                                                         -*- coding: utf-8 -*-
Changes with Apache 2.4.55

  *) mod_dav: Open the lock database read-only when possible.
     PR 36636 [Wilson Felipe <wfelipe gmail.com>, manu]

  *) mod_proxy_http2: apply the standard httpd content type handling
     to responses from the backend, as other proxy modules do. Fixes PR 66391.
     Thanks to Jérôme Billiras for providing the patch.
     [Stefan Eissing]

  *) mod_dav: mod_dav overrides dav_fs response on PUT failure. PR 35981
     [Basant Kumar Kukreja <basant.kukreja sun.com>, Alejandro Alvarez
     <alejandro.alvarez.ayllon cern.ch>]

  *) mod_proxy_hcheck: Honor worker timeout settings.  [Yann Ylavic]

  *) mod_http2: version 2.0.10 of the module, synchronizing changes
     with the gitgub version. This is a partial rewrite of how connections
     and streams are handled.
     - an APR pollset and pipes (where supported) are used to monitor
       the main connection and react to IO for request/response handling.
       This replaces the stuttered timed waits of earlier versions.
     - H2SerializeHeaders directive still exists, but has no longer an effect.
     - Clients that seemingly misbehave still get less resources allocated,
       but ongoing requests are no longer disrupted.
     - Fixed an issue since 1.15.24 that "Server" headers in proxied requests
       were overwritten instead of preserved. [PR by @daum3ns]
     - A regression in v1.15.24 was fixed that could lead to httpd child
       processes not being terminated on a graceful reload or when reaching
       MaxConnectionsPerChild. When unprocessed h2 requests were queued at
       the time, these could stall. See #212.
     - Improved information displayed in 'server-status' for H2 connections when
       Extended Status is enabled. Now one can see the last request that IO
       operations happened on and transferred IO stats are updated as well.
     - When reaching server limits, such as MaxRequestsPerChild, the HTTP/2 connection
       send a GOAWAY frame much too early on new connections, leading to invalid
       protocol state and a client failing the request. See PR65731 at
       <https://bz.apache.org/bugzilla/show_bug.cgi?id=65731>.
       The module now initializes the HTTP/2 protocol correctly and allows the
       client to submit one request before the shutdown via a GOAWAY frame
       is being announced.
     - :scheme pseudo-header values, not matching the
       connection scheme, are forwarded via absolute uris to the
       http protocol processing to preserve semantics of the request.
       Checks on combinations of pseudo-headers values/absence
       have been added as described in RFC 7540. Fixes #230.
     - A bug that prevented trailers (e.g. HEADER frame at the end) to be
       generated in certain cases was fixed. See #233 where it prevented
       gRPC responses to be properly generated.
     - Request and response header values are automatically stripped of leading
       and trialing space/tab characters. This is equivalent behaviour to what
       Apache httpd's http/1.1 parser does.
       The checks for this in nghttp2 v1.50.0+ are disabled.
     - Extensive testing in production done by Alessandro Bianchi (@alexskynet)
       on the v2.0.x versions for stability. Many thanks!
  *) mod_proxy_http2: fixed #235 by no longer forwarding 'Host:' header when
     request ':authority' is known. Improved test case that did not catch that
     the previous 'fix' was incorrect.

  *) mod_proxy_hcheck: hcmethod now allows for HTTP/1.1 requests
     using GET11, HEAD11 and/or OPTIONS11. [Jim Jagielski]

  *) mod_proxy: The AH03408 warning for a forcibly closed backend
     connection is now logged at INFO level.  [Yann Ylavic]

  *) mod_ssl: When dumping the configuration, the existence of
     certificate/key files is no longer tested.  [Joe Orton]

  *) mod_authn_core: Add expression support to AuthName and AuthType.
     [Graham Leggett]

  *) mod_ssl: when a proxy connection had handled a request using SSL, an
     error was logged when "SSLProxyEngine" was only configured in the
     location/proxy section and not the overall server. The connection
     continued to work, the error log was in error. Fixed PR66190.
     [Stefan Eissing]

  *) mod_proxy_hcheck: Re-enable workers in standard ERROR state. PR 66302.
     [Alessandro Cavaliere <alessandro.cavalier7 unibo.it>]

  *) mod_proxy_hcheck: Detect AJP/CPING support correctly. PR 66300.
     [Alessandro Cavaliere <alessandro.cavalier7 unibo.it>]

  *) mod_http2: Export mod_http2.h as public header. [Stefan Eissing]

  *) mod_md: a new directive `MDStoreLocks` can be used on cluster
     setups with a shared file system for `MDStoreDir` to order
     activation of renewed certificates when several cluster nodes are
     restarted at the same time. Store locks are not enabled by default.
     Restored curl_easy cleanup behaviour from v2.4.14 and refactored
     the use of curl_multi for OCSP requests to work with that.
     Fixes <https://github.com/icing/mod_md/issues/293>.

  *) core: Avoid an overflow on large inputs in ap_is_matchexp.  PR 66033
     [Ruediger Pluem]

  *) mod_heartmonitor: Allow "HeartbeatMaxServers 0" to use file based
     storage instead of slotmem. Needed after setting
     HeartbeatMaxServers default to the documented value 10 in 2.4.54.
     PR 66131.  [Jérôme Billiras]

  *) mod_dav: DAVlockDiscovery option to disable WebDAV lock discovery
     This is a game changer for performances if client use PROPFIND a lot,
     PR 66313. [Emmanuel Dreyfus]

Changes with Apache 2.4.54

  *) SECURITY: CVE-2022-31813: mod_proxy X-Forwarded-For dropped by
     hop-by-hop mechanism (cve.mitre.org)
     Apache HTTP Server 2.4.53 and earlier may not send the
     X-Forwarded-* headers to the origin server based on client side
     Connection header hop-by-hop mechanism.
     This may be used to bypass IP based authentication on the origin
     server/application.
     Credits: The Apache HTTP Server project would like to thank
     Gaetan Ferry (Synacktiv) for reporting this issue

  *) SECURITY: CVE-2022-30556: Information Disclosure in mod_lua with
     websockets (cve.mitre.org)
     Apache HTTP Server 2.4.53 and earlier may return lengths to
     applications calling r:wsread() that point past the end of the
     storage allocated for the buffer.
     Credits: The Apache HTTP Server project would like to thank
     Ronald Crane (Zippenhop LLC) for reporting this issue

  *) SECURITY: CVE-2022-30522: mod_sed denial of service
     (cve.mitre.org)
     If Apache HTTP Server 2.4.53 is configured to do transformations
     with mod_sed in contexts where the input to mod_sed may be very
     large, mod_sed may make excessively large memory allocations and
     trigger an abort.
     Credits: This issue was found by Brian Moussalli from the JFrog
     Security Research team

  *) SECURITY: CVE-2022-29404: Denial of service in mod_lua
     r:parsebody (cve.mitre.org)
     In Apache HTTP Server 2.4.53 and earlier, a malicious request to
     a lua script that calls r:parsebody(0) may cause a denial of
     service due to no default limit on possible input size.
     Credits: The Apache HTTP Server project would like to thank
     Ronald Crane (Zippenhop LLC) for reporting this issue

  *) SECURITY: CVE-2022-28615: Read beyond bounds in
     ap_strcmp_match() (cve.mitre.org)
     Apache HTTP Server 2.4.53 and earlier may crash or disclose
     information due to a read beyond bounds in ap_strcmp_match()
     when provided with an extremely large input buffer.  While no
     code distributed with the server can be coerced into such a
     call, third-party modules or lua scripts that use
     ap_strcmp_match() may hypothetically be affected.
     Credits: The Apache HTTP Server project would like to thank
     Ronald Crane (Zippenhop LLC) for reporting this issue

  *) SECURITY: CVE-2022-28614: read beyond bounds via ap_rwrite()
     (cve.mitre.org)
     The ap_rwrite() function in Apache HTTP Server 2.4.53 and
     earlier may read unintended memory if an attacker can cause the
     server to reflect very large input using ap_rwrite() or
     ap_rputs(), such as with mod_luas r:puts() function.
     Credits: The Apache HTTP Server project would like to thank
     Ronald Crane (Zippenhop LLC) for reporting this issue

  *) SECURITY: CVE-2022-28330: read beyond bounds in mod_isapi
     (cve.mitre.org)
     Apache HTTP Server 2.4.53 and earlier on Windows may read beyond
     bounds when configured to process requests with the mod_isapi
     module.
     Credits: The Apache HTTP Server project would like to thank
     Ronald Crane (Zippenhop LLC) for reporting this issue

  *) SECURITY: CVE-2022-26377: mod_proxy_ajp: Possible request
     smuggling (cve.mitre.org)
     Inconsistent Interpretation of HTTP Requests ('HTTP Request
     Smuggling') vulnerability in mod_proxy_ajp of Apache HTTP Server
     allows an attacker to smuggle requests to the AJP server it
     forwards requests to.  This issue affects Apache HTTP Server
     Apache HTTP Server 2.4 version 2.4.53 and prior versions.
     Credits: Ricter Z @ 360 Noah Lab

  *) mod_ssl: SSLFIPS compatible with OpenSSL 3.0.  PR 66063.
     [Petr Sumbera <petr.sumbera oracle.com>, Yann Ylavic]

  *) mod_proxy_http: Avoid 417 responses for non forwardable 100-continue.
     PR 65666.  [Yann Ylavic]

  *) mod_md:  a bug was fixed that caused very large MDomains
     with the combined DNS names exceeding ~7k to fail, as
     request bodies would contain partially wrong data from
     uninitialized memory. This would have appeared as failure
     in signing-up/renewing such configurations.
     [Stefan Eissing, Ronald Crane (Zippenhop LLC)]

  *) mod_proxy_http: Avoid 417 responses for non forwardable 100-continue.
     PR 65666.  [Yann Ylavic]

  *) MPM event: Restart children processes killed before idle maintenance.
     PR 65769.  [Yann Ylavic, Ruediger Pluem]

  *) ab: Allow for TLSv1.3 when the SSL library supports it.
     [abhilash1232 gmail.com, xiaolongx.jiang intel.com, Yann Ylavic]

  *) core: Disable TCP_NOPUSH optimization on OSX since it might introduce
     transmission delays.  PR 66019.  [Yann Ylavic]

  *) MPM event: Fix accounting of active/total processes on ungraceful restart,
     PR 66004 (follow up to PR 65626 from 2.4.52).  [Yann Ylavic]

  *) core: make ap_escape_quotes() work correctly on strings
     with more than MAX_INT/2 characters, counting quotes double.
     Credit to <generalbugs@zippenhop.com> for finding this.
     [Stefan Eissing]

  *) mod_md: the `MDCertificateAuthority` directive can take more than one URL/name of
     an ACME CA. This gives a failover for renewals when several consecutive attempts
     to get a certificate failed.
     A new directive was added: `MDRetryDelay` sets the delay of retries.
     A new directive was added: `MDRetryFailover` sets the number of errored
     attempts before an alternate CA is selected for certificate renewals.
     [Stefan Eissing]

  *) mod_http2: remove unused and insecure code. Fixes PR66037.
     Thanks to Ronald Crane (Zippenhop LLC) for reporting this.
     [Stefan Eissing]

  *) mod_proxy: Add backend port to log messages to
     ease identification of involved service.  [Rainer Jung]

  *) mod_http2: removing unscheduling of ongoing tasks when
     connection shows potential abuse by a client. This proved
     counter-productive and the abuse detection can false flag
     requests using server-side-events.
     Fixes <https://github.com/icing/mod_h2/issues/231>.
     [Stefan Eissing]

  *) mod_md: Implement full auto status ("key: value" type status output).
     Especially not only status summary counts for certificates and
     OCSP stapling but also lists. Auto status format is similar to
     what was used for mod_proxy_balancer.
     [Rainer Jung]

  *) mod_md: fixed a bug leading to failed transfers for OCSP
     stapling information when more than 6 certificates needed
     updates in the same run.  [Stefan Eissing]

  *) mod_proxy: Set a status code of 502 in case the backend just closed the
     connection in reply to our forwarded request.  [Ruediger Pluem]

  *) mod_md: a possible NULL pointer deref was fixed in
     the JSON code for persisting time periods (start+end).
     Fixes #282 on mod_md's github.
     Thanks to @marcstern for finding this.  [Stefan Eissing]

  *) mod_heartmonitor: Set the documented default value
     "10" for HeartbeatMaxServers instead of "0". With "0"
     no shared memory slotmem was initialized.  [Rainer Jung]

  *) mod_md: added support for managing certificates via a
     local tailscale daemon for users of that secure networking.
     This gives trusted certificates for tailscale assigned
     domain names in the *.ts.net space.
     [Stefan Eissing]

Changes with Apache 2.4.53

  *) SECURITY: CVE-2022-23943: mod_sed: Read/write beyond bounds
     (cve.mitre.org)
     Out-of-bounds Write vulnerability in mod_sed of Apache HTTP
     Server allows an attacker to overwrite heap memory with possibly
     attacker provided data.
     This issue affects Apache HTTP Server 2.4 version 2.4.52 and
     prior versions.
     Credits: Ronald Crane (Zippenhop LLC)

  *) SECURITY: CVE-2022-22721: core: Possible buffer overflow with
     very large or unlimited LimitXMLRequestBody (cve.mitre.org)
     If LimitXMLRequestBody is set to allow request bodies larger
     than 350MB (defaults to 1M) on 32 bit systems an integer
     overflow happens which later causes out of bounds writes.
     This issue affects Apache HTTP Server 2.4.52 and earlier.
     Credits: Anonymous working with Trend Micro Zero Day Initiative

  *) SECURITY: CVE-2022-22720: HTTP request smuggling vulnerability
     in Apache HTTP Server 2.4.52 and earlier (cve.mitre.org)
     Apache HTTP Server 2.4.52 and earlier fails to close inbound
     connection when errors are encountered discarding the request
     body, exposing the server to HTTP Request Smuggling
     Credits: James Kettle <james.kettle portswigger.net>

  *) SECURITY: CVE-2022-22719: mod_lua Use of uninitialized value of
     in r:parsebody (cve.mitre.org)
     A carefully crafted request body can cause a read to a random
     memory area which could cause the process to crash.
     This issue affects Apache HTTP Server 2.4.52 and earlier.
     Credits: Chamal De Silva

  *) core: Make sure and check that LimitXMLRequestBody fits in system memory.
     [Ruediger Pluem, Yann Ylavic]

  *) core: Simpler connection close logic if discarding the request body fails.
     [Yann Ylavic, Ruediger Pluem]

  *) mod_http2: preserve the port number given in a HTTP/1.1
     request that was Upgraded to HTTP/2. Fixes PR65881.
     [Stefan Eissing]

  *) mod_proxy: Allow for larger worker name.  PR 53218.  [Yann Ylavic]

  *) dbm: Split the loading of a dbm driver from the opening of a dbm file. When
     an attempt to load a dbm driver fails, log clearly which driver triggered
     the error (not "default"), and what the error was. [Graham Leggett]

  *) mod_proxy: Use the maxium of front end and backend timeouts instead of the
     minimum when tunneling requests (websockets, CONNECT requests).
     Backend timeouts can be configured more selectively (per worker if needed)
     as front end timeouts and typically the backend timeouts reflect the
     application requirements better.  PR 65886 [Ruediger Pluem]

  *) ap_regex: Use Thread Local Storage (TLS) to recycle ap_regexec() buffers
     when an efficient TLS implementation is available. [Yann Ylavic]

  *) core, mod_info: Add compiled and loaded PCRE versions to version
     number display.  [Rainer Jung]

  *) mod_md: do not interfere with requests to /.well-known/acme-challenge/
     resources if challenge type 'http-01' is not configured for a domain.
     Fixes <https://github.com/icing/mod_md/issues/279>.
     [Stefan Eissing]

  *) mod_dav: Fix regression when gathering properties which could lead to huge
     memory consumption proportional to the number of resources.
     [Evgeny Kotkov, Ruediger Pluem]

  *) Support pcre2 (10.x) library in place of the now end-of-life pcre (8.x)
     for regular expression evaluation. This depends on locating pcre2-config.
     [William Rowe, Petr Pisar <ppisar redhat.com>, Rainer Jung]

  *) Add the ldap function to the expression API, allowing LDAP filters and
     distinguished names based on expressions to be escaped correctly to
     guard against LDAP injection. [Graham Leggett]

  *) mod_md: the status description in MDomain's JSON, exposed in the
     md-status handler (if configured) did sometimes not carry the correct
     message when certificates needed renew.
     [Stefan Eissing]

  *) mpm_event: Fix a possible listener deadlock on heavy load when restarting
     and/or reaching MaxConnectionsPerChild.  PR 65769.  [Yann Ylavic]

Changes with Apache 2.4.52

  *) SECURITY: CVE-2021-44790: Possible buffer overflow when parsing
     multipart content in mod_lua of Apache HTTP Server 2.4.51 and
     earlier (cve.mitre.org)
     A carefully crafted request body can cause a buffer overflow in
     the mod_lua multipart parser (r:parsebody() called from Lua
     scripts).
     The Apache httpd team is not aware of an exploit for the
     vulnerability though it might be possible to craft one.
     This issue affects Apache HTTP Server 2.4.51 and earlier.
     Credits: Chamal

  *) SECURITY: CVE-2021-44224: Possible NULL dereference or SSRF in
     forward proxy configurations in Apache HTTP Server 2.4.51 and
     earlier (cve.mitre.org)
     A crafted URI sent to httpd configured as a forward proxy
     (ProxyRequests on) can cause a crash (NULL pointer dereference)
     or, for configurations mixing forward and reverse proxy
     declarations, can allow for requests to be directed to a
     declared Unix Domain Socket endpoint (Server Side Request
     Forgery).
     This issue affects Apache HTTP Server 2.4.7 up to 2.4.51
     (included).
     Credits: 漂亮鼠
     TengMA(@Te3t123)

  *) http: Enforce that fully qualified uri-paths not to be forward-proxied
     have an http(s) scheme, and that the ones to be forward proxied have a
     hostname, per HTTP specifications.  [Ruediger Pluem, Yann Ylavic]

  *) configure: OpenSSL detection will now use pkg-config data from
     .../lib64/ within the --with-ssl path. [Jean-Frederic Clere]

  *) mod_proxy_connect, mod_proxy: Do not change the status code after we
     already sent it to the client. [Ruediger Pluem]

  *) mod_http: Correctly sent a 100 Continue status code when sending an interim
     response as result of an Expect: 100-Continue in the request and not the
     current status code of the request. PR 65725 [Ruediger Pluem]

  *) mod_dav: Some DAV extensions, like CalDAV, specify both document
     elements and property elements that need to be taken into account
     when generating a property. The document element and property element
     are made available in the dav_liveprop_elem structure by calling
     dav_get_liveprop_element(). [Graham Leggett]

  *) mod_dav: Add utility functions dav_validate_root_ns(),
     dav_find_child_ns(), dav_find_next_ns(), dav_find_attr_ns() and
     dav_find_attr() so that other modules get to play too.
     [Graham Leggett]

  *) mpm_event: Restart stopping of idle children after a load peak. PR 65626.
     [Yann Ylavic, Ruediger Pluem]

  *) mod_http2: fixes 2 regressions in server limit handling.
     1. When reaching server limits, such as MaxRequestsPerChild, the
        HTTP/2 connection send a GOAWAY frame much too early on new
        connections, leading to invalid protocol state and a client
        failing the request. See PR65731.
        The module now initializes the HTTP/2 protocol correctly and
        allows the client to submit one request before the shutdown
        via a GOAWAY frame is being announced.
     2. A regression in v1.15.24 was fixed that could lead to httpd
        child processes not being terminated on a graceful reload or
        when reaching MaxConnectionsPerChild. When unprocessed h2
        requests were queued at the time, these could stall.
        See <https://github.com/icing/mod_h2/issues/212>.
     [Stefan Eissing]

  *) mod_ssl: Add build support for OpenSSL v3. [Rainer Jung,
     Stefan Fritsch, Yann Ylavic, Stefan Eissing, Joe Orton,
     Giovanni Bechis]

  *) mod_proxy_connect: Honor the smallest of the backend or client timeout
     while tunneling.  [Yann Ylavic]

  *) mod_proxy: SetEnv proxy-nohalfclose (or alike) allows to disable TCP
     half-close forwarding when tunneling protocols.  [Yann Ylavic]

  *) core: Be safe with ap_lingering_close() called with a socket NULL-ed by
     a third-party module.  PR 65627.
     [acmondor <bz.apache.org acmondor.ca>, Yann Ylavic]

  *) mod_md: Fix memory leak in case of failures to load the private key.
     PR 65620 [ Filipe Casal <filipe.casal@trailofbits.com> ]

  *) mod_md: adding v2.4.8 with the following changes
    - Added support for ACME External Account Binding (EAB).
      Use the new directive `MDExternalAccountBinding` to provide the
      server with the value for key identifier and hmac as provided by
      your CA.
      While working on some servers, EAB handling is not uniform
      across CAs. First tests with a Sectigo Certificate Manager in
      demo mode are successful. But ZeroSSL, for example, seems to
      regard EAB values as a one-time-use-only thing, which makes them
      fail if you create a seconde account or retry the creation of the
      first account with the same EAB.
    - The directive 'MDCertificateAuthority' now checks if its parameter
      is a http/https url or one of a set of known names. Those are
      'LetsEncrypt', 'LetsEncrypt-Test', 'Buypass' and 'Buypass-Test'
      for now and they are not case-sensitive.
      The default of LetsEncrypt is unchanged.
    - `MDContactEmail` can now be specified inside a `<MDomain dnsname>`
      section.
    - Treating 401 HTTP status codes for orders like 403, since some ACME
      servers seem to prefer that for accessing oders from other accounts.
    - When retrieving certificate chains, try to read the response even
      if the HTTP Content-Type is unrecognized.
    - Fixed a bug that reset the error counter of a certificate renewal
      and prevented the increasing delays in further attempts.
    - Fixed the renewal process giving up every time on an already existing
      order with some invalid domains. Now, if such are seen in a previous
      order, a new order is created for a clean start over again.
      See <https://github.com/icing/mod_md/issues/268>
    - Fixed a mixup in md-status handler when static certificate files
      and renewal was configured at the same time.

  *) mod_md: values for External Account Binding (EAB) can
     now also be configured to be read from a separate JSON
     file. This allows to keep server configuration permissions
     world readable without exposing secrets.
     [Stefan Eissing]

  *) mod_proxy_uwsgi: Remove duplicate slashes at the beginning of PATH_INFO.
     PR 65616.  [Ruediger Pluem]

Changes with Apache 2.4.51

  *) SECURITY: CVE-2021-42013: Path Traversal and Remote Code
     Execution in Apache HTTP Server 2.4.49 and 2.4.50 (incomplete
     fix of CVE-2021-41773) (cve.mitre.org)
     It was found that the fix for CVE-2021-41773 in Apache HTTP
     Server 2.4.50 was insufficient.  An attacker could use a path
     traversal attack to map URLs to files outside the directories
     configured by Alias-like directives.
     If files outside of these directories are not protected by the
     usual default configuration "require all denied", these requests
     can succeed. If CGI scripts are also enabled for these aliased
     paths, this could allow for remote code execution.
     This issue only affects Apache 2.4.49 and Apache 2.4.50 and not
     earlier versions.
     Credits: Reported by Juan Escobar from Dreamlab Technologies,
     Fernando Muñoz from NULL Life CTF Team, and Shungo Kumasaka

  *) core: Add ap_unescape_url_ex() for better decoding control, and deprecate
     unused AP_NORMALIZE_DROP_PARAMETERS flag.
     [Yann Ylavic, Ruediger Pluem, Stefan Eissing, Joe Orton]

Changes with Apache 2.4.50

  *) SECURITY: CVE-2021-41773: Path traversal and file disclosure
     vulnerability in Apache HTTP Server 2.4.49 (cve.mitre.org)
     A flaw was found in a change made to path normalization in
     Apache HTTP Server 2.4.49. An attacker could use a path
     traversal attack to map URLs to files outside the expected
     document root.
     If files outside of the document root are not protected by
     "require all denied" these requests can succeed. Additionally
     this flaw could leak the source of interpreted files like CGI
     scripts.
     This issue is known to be exploited in the wild.
     This issue only affects Apache 2.4.49 and not earlier versions.
     Credits: This issue was reported by Ash Daulton along with the
     cPanel Security Team

  *) SECURITY: CVE-2021-41524: null pointer dereference in h2 fuzzing
     (cve.mitre.org)
     While fuzzing the 2.4.49 httpd, a new null pointer dereference
     was detected during HTTP/2 request processing,
     allowing an external source to DoS the server. This requires a
     specially crafted request.
     The vulnerability was recently introduced in version 2.4.49. No
     exploit is known to the project.
     Credits: Apache httpd team would like to thank LI ZHI XIN from
     NSFocus Security Team for reporting this issue.

  *) core: AP_NORMALIZE_DECODE_UNRESERVED should normalize the second dot in
     the uri-path when it's preceded by a dot.  [Yann Ylavic]

  *) mod_md: when MDMessageCmd for a 'challenge-setup:<type>:<dnsname>'
     fails (!= 0 exit), the renewal process is aborted and an error is
     reported for the MDomain. This provides scripts that distribute
     information in a cluster to abort early with bothering an ACME
     server to validate a dns name that will not work. The common
     retry logic will make another attempt in the future, as with
     other failures.
     Fixed a bug when adding private key specs to an already working
     MDomain, see <https://github.com/icing/mod_md/issues/260>.
     [Stefan Eissing]

  *) mod_proxy: Handle UDS URIs with empty hostname ("unix:///...") as if they
     had no hostname ("unix:/...").  [Yann Ylavic]

  *) mod_md: fixed a bug in handling multiple parallel OCSP requests. These could
     run into an assertion which terminated (and restarted) the child process where
     the task was running. Eventually, all OCSP responses were collected, but not
     in the way that things are supposed to work.
     See also <https://bz.apache.org/bugzilla/show_bug.cgi?id=65567>.
     The bug was possibly triggered when more than one OCSP status needed updating
     at the same time. For example for several renewed certificates after a server
     reload.

  *) mod_rewrite: Fix UDS ("unix:") scheme for [P] rules.  PR 57691 + 65590.
     [Janne Peltonen <janne.peltonen sange.fi>]

  *) event mpm: Correctly count active child processes in parent process if
     child process dies due to MaxConnectionsPerChild.
     PR 65592 [Ruediger Pluem]

  *) mod_http2: when a server is restarted gracefully, any idle h2 worker
     threads are shut down immediately.
     Also, change OpenSSL API use for deprecations in OpenSSL 3.0.
     Adds all other, never proposed code changes to make a clean
     sync of http2 sources. [Stefan Eissing]

  *) mod_dav: Correctly handle errors returned by dav providers on REPORT
     requests. [Ruediger Pluem]

  *) core: do not install core input/output filters on secondary
     connections. [Stefan Eissing]

  *) core: Add ap_pre_connection() as a wrapper to ap_run_pre_connection()
     and use it to prevent that failures in running the pre_connection
     hook cause crashes afterwards. [Ruediger Pluem]

  *) mod_speling: Add CheckBasenameMatch PR 44221.  [Christophe Jaillet]

Changes with Apache 2.4.49

  *) SECURITY: CVE-2021-40438 (cve.mitre.org)
     mod_proxy: Server Side Request Forgery (SSRF) vulnerability [Yann Ylavic]

  *) SECURITY: CVE-2021-39275 (cve.mitre.org)
     core: ap_escape_quotes buffer overflow

  *) SECURITY: CVE-2021-36160 (cve.mitre.org)
     mod_proxy_uwsgi: Out of bound read vulnerability [Yann Ylavic]

  *) SECURITY: CVE-2021-34798 (cve.mitre.org)
     core: null pointer dereference on malformed request

  *) SECURITY: CVE-2021-33193 (cve.mitre.org)
     mod_http2: Request splitting vulnerability with mod_proxy [Stefan Eissing]

  *) core/mod_proxy/mod_ssl:
     Adding `outgoing` flag to conn_rec, indicating a connection is
     initiated by the server to somewhere, in contrast to incoming
     connections from clients.
     Adding 'ap_ssl_bind_outgoing()` function that marks a connection
     as outgoing and is used by mod_proxy instead of the previous
     optional function `ssl_engine_set`. This enables other SSL
     module to secure proxy connections.
     The optional functions `ssl_engine_set`, `ssl_engine_disable` and
     `ssl_proxy_enable` are now provided by the core to have backward
     compatibility with non-httpd modules that might use them. mod_ssl
     itself no longer registers these functions, but keeps them in its
     header for backward compatibility.
     The core provided optional function wrap any registered function
     like it was done for `ssl_is_ssl`.
     [Stefan Eissing]

  *) mod_ssl: Support logging private key material for use with
     wireshark via log file given by SSLKEYLOGFILE environment
     variable.  Requires OpenSSL 1.1.1.  PR 63391.  [Joe Orton]

  *) mod_proxy: Do not canonicalize the proxied URL when both "nocanon" and
     "ProxyPassInterpolateEnv On" are configured.  PR 65549.
     [Joel Self <joelself gmail.com>]

  *) mpm_event: Fix children processes possibly not stopped on graceful
     restart.  PR 63169.  [Joel Self <joelself gmail.com>]

  *) mod_proxy: Fix a potential infinite loop when tunneling Upgrade(d)
     protocols from mod_proxy_http, and a timeout triggering falsely when
     using mod_proxy_wstunnel, mod_proxy_connect or mod_proxy_http with
     upgrade= setting.  PRs 65521 and 65519.  [Yann Ylavic]

  *) mod_unique_id: Reduce the time window where duplicates may be generated
     PR 65159
     [Christophe Jaillet]

  *) mpm_prefork: Block signals for child_init hooks to prevent potential
     threads created from there to catch MPM's signals.
     [Ruediger Pluem, Yann Ylavic]

  *) Revert "mod_unique_id: Fix potential duplicated ID generation under heavy load.
     PR 65159" added in 2.4.47.
     This causes issue on Windows.
     [Christophe Jaillet]

  *) mod_proxy_uwsgi: Fix PATH_INFO setting for generic worker.  [Yann Ylavic]

  *) mod_md: Certificate/keys pairs are verified as matching before a renewal is accepted
     as successful or a staged renewal is replacing the existing certificates.
     This avoid potential mess ups in the md store file system to render the active
     certificates non-working. [@mkauf]

  *) mod_proxy: Faster unix socket path parsing in the "proxy:" URL.
     [Yann Ylavic]

  *) mod_ssl: tighten the handling of ALPN for outgoing (proxy)
     connections. If ALPN protocols are provided and sent to the
     remote server, the received protocol selected is inspected
     and checked for a match. Without match, the peer handshake
     fails.
     An exception is the proposal of "http/1.1" where it is
     accepted if the remote server did not answer ALPN with
     a selected protocol. This accommodates for hosts that do
     not observe/support ALPN and speak http/1.x be default.

  *) mod_proxy: Fix possible reuse/merging of Proxy(Pass)Match worker instances
     with others when their URLs contain a '$' substitution.  PR 65419 + 65429.
     [Yann Ylavic]

  *) mod_dav: Add method_precondition hook. WebDAV extensions define
     conditions that must exist before a WebDAV method can be executed.
     This hook allows a WebDAV extension to verify these preconditions.
     [Graham Leggett]

  *) Add hooks deliver_report and gather_reports to mod_dav.h. Allows other
     modules apart from versioning implementations to handle the REPORT method.
     [Graham Leggett]

  *) Add dav_get_provider(), dav_open_lockdb(), dav_close_lockdb() and
     dav_get_resource() to mod_dav.h. [Graham Leggett]

  *) core: fix ap_escape_quotes substitution logic. [Eric Covener]

  *) core/mpm: add hook 'child_stopping` that gets called when the MPM is
     stopping a child process. The additional `graceful` parameter allows
     registered hooks to free resources early during a graceful shutdown.
     [Yann Ylavic, Stefan Eissing]

  *) mod_proxy: Fix icomplete initialization of BalancerMember(s) from the
     balancer-manager, which can lead to a crash.  [Yann Ylavic]

  *) mpm_event: Fix graceful stop/restart of children processes if connections
     are in lingering close for too long.  [Yann Ylavic]

  *) mod_md: fixed a potential null pointer dereference if ACME/OCSP
     server returned 2xx responses without content type. Reported by chuangwen.
     [chuangwen, Stefan Eissing]

  *) mod_md:
     - Domain names in `<MDomain ...>` can now appear in quoted form.
     - Fixed a failure in ACME challenge selection that aborted further searches
       when the tls-alpn-01 method did not seem to be suitable.
     - Changed the tls-alpn-01 setup to only become unsuitable when none of the
       dns names showed support for a configured 'Protocols ... acme-tls/1'. This
       allows use of tls-alpn-01 for dns names that are not mapped to a VirtualHost.
     [Stefan Eissing]

  *) Add CPING to health check logic. [Jean-Frederic Clere]

  *) core: Split ap_create_request() from ap_read_request(). [Graham Leggett]

  *) core, h2: common ap_parse_request_line() and ap_check_request_header()
     code. [Yann Ylavic]

  *) core: Add StrictHostCheck to allow unconfigured hostnames to be
     rejected. [Eric Covener]

  *) htcacheclean: Improve help messages.  [Christophe Jaillet]

Changes with Apache 2.4.48

  *) SECURITY: CVE-2021-31618 (cve.mitre.org)
     mod_http2: Fix a potential NULL pointer dereference [Ivan Zhakov]

  *) mod_proxy_wstunnel: Add ProxyWebsocketFallbackToProxyHttp to opt-out the
     fallback to mod_proxy_http for WebSocket upgrade and tunneling.
     [Yann Ylavic]

  *) mod_proxy: Fix flushing of THRESHOLD_MIN_WRITE data while tunneling.
     BZ 65294.  [Yann Ylavic]

  *) core: Fix a regression that stripped the ETag header from 304 responses.
     PR 61820 [Ruediger Pluem, Roy T. Fielding]

  *) core: Adding SSL related inquiry functions to the server API.
     These function are always available, even when no module providing
     SSL is loaded. They provide their own "shadowing" implementation for
     the optional functions of similar name that mod_ssl and impersonators
     of mod_ssl provide.
     This enables loading of several SSL providing modules when all but
     one of them registers itself into the new hooks. Two old-style SSL
     modules will not work, as they replace the others optional functions
     with their own.
     Modules using the old-style optional functions will continue to work
     as core supplies its own versions of those.
     The following has been added so far:
     - ap_ssl_conn_is_ssl() to query if a connection is using SSL.
     - ap_ssl_var_lookup() to query SSL related variables for a
       server/connection/request.
     - Hooks for 'ssl_conn_is_ssl' and 'ssl_var_lookup' where modules
       providing SSL can install their own value supplying functions.
     - ap_ssl_add_cert_files() to enable other modules like mod_md to provide
       certificate and keys for an SSL module like mod_ssl.
     - ap_ssl_add_fallback_cert_files() to enable other modules like mod_md to
       provide a fallback certificate in case no 'proper' certificate is
       available for an SSL module like mod_ssl.
     - ap_ssl_answer_challenge() to enable other modules like mod_md to
       provide a certificate as used in the RFC 8555 'tls-alpn-01' challenge
       for the ACME protocol for an SSL module like mod_ssl. The function
       and its hook provide PEM encoded data instead of file names.
     - Hooks for 'ssl_add_cert_files', 'ssl_add_fallback_cert_files' and
       'ssl_answer_challenge' where modules like mod_md can provide providers
       to the above mentioned functions.
     - These functions reside in the new 'http_ssl.h' header file.
     [Stefan Eissing]

  *) core/mod_ssl/mod_md: adding OCSP response provisioning as core feature. This
     allows modules to access and provide OCSP response data without being tied
     of each other. The data is exchanged in standard, portable formats (PEM encoded
     certificates and DER encoded responses), so that the actual SSL/crypto
     implementations used by the modules are independant of each other.
     Registration and retrieval happen in the context of a server (server_rec)
     which modules may use to decide if they are configured for this or not.
     The area of changes:
     1. core: defines 2 functions in include/http_ssl.h, so that modules may
        register a certificate, together with its issuer certificate for OCSP
        response provisioning and ask for current response data (DER bytes) later.
        Also, 2 hooks are defined that allow modules to implement this OCSP
        provisioning.
     2. mod_ssl uses the new functions, in addition to what it did already, to
        register its certificates this way. If no one is interested in providing
        OCSP, it falls back to its own (if configured) stapling implementation.
     3. mod_md registers itself at the core hooks for OCSP provisioning. Depending
        on configuration, it will accept registrations of its own certificates only,
        all certificates or none.
     [Stefan Eissing]

 *) mod_md: v2.4.0 with improvements and bugfixes
     - MDPrivateKeys allows the specification of several types. Beside "RSA" plus
     optional key lengths elliptic curves can be configured. This means you can
     have multiple certificates for a Managed Domain with different key types.
     With ```MDPrivateKeys secp384r1 rsa2048``` you get one ECDSA  and one RSA
     certificate and all modern client will use the shorter ECDSA, while older
     client will get the RSA certificate.
     Many thanks to @tlhackque who pushed and helped on this.
     - Support added for MDomains consisting of a wildcard. Configuring
     ```MDomain *.host.net``` will match all virtual hosts matching that pattern
     and obtain one certificate for it (assuming you have 'dns-01' challenge
     support configured). Addresses #239.
     - Removed support for ACMEv1 servers. The only known installation used to
     be Let's Encrypt which has disabled that version more than a year ago for
     new accounts.
     - Andreas Ulm (<https://github.com/root360-AndreasUlm>) implemented the
     ```renewing``` call to ```MDMessageCmd``` that can deny a certificate
     renewal attempt. This is useful in clustered installations, as
     discussed in #233).
     - New event ```challenge-setup:<type>:<domain>```, triggered when the
     challenge data for a domain has been created. This is invoked before the
     ACME server is told to check for it. The type is one of the ACME challenge
     types. This is invoked for every DNS name in a MDomain.
     - The max delay for retries has been raised to daily (this is like all
     retries jittered somewhat to avoid repeats at fixed time of day).
     - Certain error codes reported by the ACME server that indicate a problem
     with the configured data now immediately switch to daily retries. For
     example: if the ACME server rejects a contact email or a domain name,
     frequent retries will most likely not solve the problem. But daily retries
     still make sense as there might be an error at the server and un-supervised
     certificate renewal is the goal. Refs #222.
     - Test case and work around for domain names > 64 octets. Fixes #227.
     When the first DNS name of an MD is longer than 63 octets, the certificate
     request will not contain a CN field, but leave it up to the CA to choose one.
     Currently, Lets Encrypt looks for a shorter name in the SAN list given and
     fails the request if none is found. But it is really up to the CA (and what
     browsers/libs accept here) and may change over the years. That is why
     the decision is best made at the CA.
     - Retry delays now have a random +/-[0-50]% modification applied to let
     retries from several servers spread out more, should they have been
     restarted at the same time of day.
     - Fixed several places where the 'badNonce' return code from an ACME server
     was not handled correctly. The test server 'pebble' simulates this behaviour
     by default and helps nicely in verifying this behaviour. Thanks, pebble!
     - Set the default `MDActivationDelay` to 0. This was confusing to users that
     new certificates were deemed not usably before a day of delay. When clocks are
     correct, using a new certificate right away should not pose a problem.
     - When handling ACME authorization resources, the module no longer requires
     the server to return a "Location" header, as was necessary in ACMEv1.
     Fixes #216.
     - Fixed a theoretical uninitialized read when testing for JSON error responses
     from the ACME CA. Reported at <https://bz.apache.org/bugzilla/show_bug.cgi?id=64297>.
     - ACME problem reports from CAs that include parameters in the Content-Type
     header are handled correctly. (Previously, the problem text would not be
     reported and retries could exceed CA limits.)
     - Account Update transactions to V2 CAs now use the correct POST-AS-GET method.
     Previously, an empty JSON object was sent - which apparently LE accepted,
     but others reject.
     [Stefan Eissing, @tlhackque, Andreas Ulm]

Changes with Apache 2.4.47

  *) SECURITY: CVE-2021-30641 (cve.mitre.org)
     Unexpected <Location> section matching with 'MergeSlashes OFF'

  *) SECURITY: CVE-2020-35452 (cve.mitre.org)
     mod_auth_digest: possible stack overflow by one nul byte while validating
     the Digest nonce.  [Yann Ylavic]

  *) SECURITY: CVE-2021-26691 (cve.mitre.org)
     mod_session: Fix possible crash due to NULL pointer dereference, which
     could be used to cause a Denial of Service with a malicious backend
     server and SessionHeader.  [Yann Ylavic]

  *) SECURITY: CVE-2021-26690 (cve.mitre.org)
     mod_session: Fix possible crash due to NULL pointer dereference, which
     could be used to cause a Denial of Service.  [Yann Ylavic]

  *) SECURITY: CVE-2020-13950 (cve.mitre.org)
     mod_proxy_http: Fix possible crash due to NULL pointer dereference, which
     could be used to cause a Denial of Service.  [Yann Ylavic]

  *) SECURITY: CVE-2020-13938 (cve.mitre.org)
     Windows: Prevent local users from stopping the httpd process [Ivan Zhakov]

  *) SECURITY: CVE-2019-17567 (cve.mitre.org)
     mod_proxy_wstunnel, mod_proxy_http: Handle Upgradable protocols end-to-end
     negotiation.  [Yann Ylavic]

  *) mod_dav_fs: Improve logging output when failing to open files for
     writing.  PR 64413.  [Bingyu Shen <ahshenbingyu gmail.com>]

  *) mod_http2: Fixed a race condition that could lead to streams being
     aborted (RST to the client), although a response had been produced.
     [Stefan Eissing]

  *) mod_lua: Add support to Lua 5.4  [Joe Orton, Giovanni Bechis, Ruediger Pluem]

  *) MPM event/worker: Fix possible crash in child process on early signal
     delivery.  PR 64533.  [Ruediger Pluem]

  *) mod_http2: sync with github standalone version 1.15.17
     - Log requests and sent the configured error response in case of early detected
       errors like too many or too long headers. [Ruediger Pluem]
     - new option 'H2OutputBuffering on/off' which controls the buffering of stream output.
       The default is on, which is the behaviour of older mod-h2 versions. When off, all
       bytes are made available immediately to the main connection for sending them
       out to the client. This fixes interop issues with certain flavours of gRPC, see
       also <https://github.com/icing/mod_h2/issues/207>.
       [Stefan Eissing]

  *) mod_unique_id: Fix potential duplicated ID generation under heavy load.
     PR 65159
     [Jonas Müntener <jonas.muentener ergon.ch>, Christophe Jaillet]

  *) "[mod_dav_fs etag handling] should really honor the FileETag setting".
     - It now does.
     - Add "Digest" to FileETag directive, allowing a strong ETag to be
       generated using a file digest.
     - Add ap_make_etag_ex() and ap_set_etag_fd() to allow full control over
       ETag generation.
     - Add concept of "binary notes" to request_rec, allowing packed bit flags
       to be added to a request.
     - First binary note - AP_REQUEST_STRONG_ETAG - allows modules to force
       the ETag to a strong ETag to comply with RFC requirements, such as those
       mandated by various WebDAV extensions.
     [Graham Leggett]

  *) mod_proxy_http: Fix a possibly crash when the origin connection gets
     interrupted before completion.  PR 64234.
     [Barnim Dzwillo <dzwillo strato.de>, Ruediger Pluem]

  *) mod_ssl: Do not keep connections to OCSP responders alive when doing
     OCSP requests.  PR 64135.  [Ruediger Pluem]

  *) mod_ssl: Improve the coalescing filter to buffer into larger TLS
     records, and avoid revealing the HTTP header size via TLS record
     boundaries (for common response generators).
     [Joe Orton, Ruediger Pluem]

  *) mod_proxy_hcheck: Don't pile up health checks if the previous one did
     not finish before hcinterval.  PR 63010.  [Yann Ylavic]

  *) mod_session: Improve session parsing.  [Yann Yalvic]

  *) mod_authnz_ldap: Prevent authentications with empty passwords for the
     initial bind to fail with status 500. [Ruediger Pluem]

  *) mod_proxy_fcgi: Honor "SetEnv proxy-sendcl" to forward a chunked
     Transfer-Encoding from the client, spooling the request body when needed
     to provide a Content-Length to the backend.  PR 57087.  [Yann Ylavic]

  *) mod_proxy: Improve tunneling loop to support half closed connections and
     pending data draining (for protocols like rsync). PR 61616. [Yann Ylavic]

  *) mod_proxy_wstunnel: Leave Upgrade requests handling to mod_proxy_http,
     allowing for (non-)Upgrade negotiation with the origin server.
     [Yann Ylavic]

  *) mod_proxy: Allow ProxyErrorOverride to be restricted to specific status
     codes.  PR63628. [Martin Drößler <mail martindroessler.de>]

  *) core: Add ReadBufferSize, FlushMaxThreshold and FlushMaxPipelined
     directives.  [Yann Ylavic]

  *) core: Ensure that aborted connections are logged as such. PR 62823
     [Arnaud Grandville <contact@grandville.net>]

  *) http: Allow unknown response status' lines returned in the form of
     "HTTP/x.x xxx Status xxx".  [Yann Ylavic]

  *) mod_proxy_http: Fix 100-continue deadlock for spooled request bodies,
     leading to Request Timeout (408).  PR 63855.  [Yann Ylavic]

  *) core: Remove headers on 304 Not Modified as specified by RFC7234, as
     opposed to passing an explicit subset of headers. PR 61820.
     [Giovanni Bechis]

  *) mpm_event: Don't reset connections after lingering close, restoring prior
     to 2.4.28 behaviour.  [Yann Ylavic]

  *) mpm_event: Kill connections in keepalive state only when there is no more
     workers available, not when the maximum number of connections is reached,
     restoring prior to 2.4.30 behaviour.  [Yann Ylavic]

  *) mod_unique_id: Use base64url encoding for UNIQUE_ID variable,
     avoiding the use of '@'.  PR 57044.
     [Michael Kaufmann <apache-bugzilla michael-kaufmann.ch>]

  *) mod_rewrite: Extend the [CO] (cookie) flag of RewriteRule to accept a
     SameSite attribute. [Eric Covener]

  *) mod_proxy: Add proxy check_trans hook.  This allows proxy
     modules to decline request handling at early stage.

  *) mod_proxy_wstunnel: Decline requests without an Upgrade
     header so ws/wss can be enabled overlapping with later
     http/https.

  *) mod_http2: Log requests and sent the configured error response in case of
     early detected errors like too many or too long headers.
     [Ruediger Pluem, Stefan Eissing]

  *) mod_md: Lowered the required minimal libcurl version from 7.50 to 7.29
     as proposed by <alexander.gerasimov codeit.pro>. [Stefan Eissing]

  *) mod_ssl: Fix request body buffering with PHA in TLSv1.3.  [Joe Orton]

  *) mod_proxy_uwsgi: Fix a crash when sending environment variables with no
     value. PR 64598 [Ruediger Pluem]

  *) mod_proxy: Recognize parameters from ProxyPassMatch workers with dollar
     substitution, such that they apply to the backend connection.  Note that
     connection reuse is disabled by default to avoid compatibility issues.
     [Takashi Sato, Jan Kaluza, Eric Covener, Yann Ylavic, Jean-Frederic Clere]

Changes with Apache 2.4.46

  *) SECURITY: CVE-2020-11984 (cve.mitre.org)
     mod_proxy_uwsgi: Malicious request may result in information disclosure
     or RCE of existing file on the server running under a malicious process
     environment. [Yann Ylavic]

  *) SECURITY: CVE-2020-11993 (cve.mitre.org)
     mod_http2: when throttling connection requests, log statements
     where possibly made that result in concurrent, unsafe use of
     a memory pool. [Stefan Eissing]

  *) SECURITY: CVE-2020-9490 (cve.mitre.org)
     mod_http2: a specially crafted value for the 'Cache-Digest' header
     request would result in a crash when the server actually tries
     to HTTP/2 PUSH a resource afterwards. [Stefan Eissing]

  *) mod_proxy_fcgi: Fix missing APLOGNO macro argument
     [Eric Covener, Christophe Jaillet]

Changes with Apache 2.4.45

  *) mod_http2: remove support for abandoned http-wg draft
     <https://datatracker.ietf.org/doc/draft-kazuho-h2-cache-digest/>.
     [Stefan Eissing]

Changes with Apache 2.4.44

  *) mod_proxy_uwsgi: Error out on HTTP header larger than 16K (hard
     protocol limit).  [Yann Ylavic]

  *) mod_http2:
     Fixes <https://github.com/icing/mod_h2/issues/200>:
     "LimitRequestFields 0" now disables the limit, as documented.
     Fixes <https://github.com/icing/mod_h2/issues/201>:
     Do not count repeated headers with same name against the field
     count limit. The are merged internally, as if sent in a single HTTP/1 line.
     [Stefan Eissing]

  *) mod_http2: Avoid segfaults in case of handling certain responses for
     already aborted connections.  [Stefan Eissing, Ruediger Pluem]

  *) mod_http2: The module now handles master/secondary connections and has marked
     methods according to use. [Stefan Eissing]

  *) core: Drop an invalid Last-Modified header value coming
     from a FCGI/CGI script instead of replacing it with Unix epoch.
     [Yann Ylavic, Luca Toscano]

  *) Add support for strict content-length parsing through addition of
     ap_parse_strict_length() [Yann Ylavic]

  *) mod_proxy_fcgi: ProxyFCGISetEnvIf unsets variables when expression
     evaluates to false.  PR64365. [Michael König <mail ikoenig.net>]

  *) mod_proxy_http: flush spooled request body in one go to avoid
     leaking (or long lived) temporary file. PR 64452. [Yann Ylavic]

  *) mod_ssl: Fix a race condition and possible crash when using a proxy client
     certificate (SSLProxyMachineCertificateFile).
     [Armin Abfalterer <a.abfalterer gmail.com>]

  *) mod_ssl: Fix memory leak in stapling code. PR63687. [Stefan Eissing]

  *) mod_http2: Fixed regression that no longer set H2_STREAM_ID and H2_STREAM_TAG.
     PR64330 [Stefan Eissing]

  *) mod_http2: Fixed regression that caused connections to close when mod_reqtimeout
     was configured with a handshake timeout. Fixes gitub issue #196.
     [Stefan Eissing]

  *) mod_proxy_http2: the "ping" proxy parameter
     (see <https://httpd.apache.org/docs/2.4/mod/mod_proxy.html>) is now used
     when checking the liveliness of a new or reused h2 connection to the backend.
     With short durations, this makes load-balancing more responsive. The module
     will hold back requests until ping conditions are met, using features of the
     HTTP/2 protocol alone. [Ruediger Pluem, Stefan Eissing]

  *) core: httpd is no longer linked against -lsystemd if mod_systemd
     is enabled (and built as a DSO).  [Rainer Jung]

  *) mod_proxy_http2: respect ProxyTimeout settings on backend connections
     while waiting on incoming data. [Ruediger Pluem, Stefan Eissing]

Changes with Apache 2.4.43

  *) mod_ssl: Fix memory leak of OCSP stapling response. [Yann Ylavic]

Changes with Apache 2.4.42

  *) SECURITY: CVE-2020-1934 (cve.mitre.org)
     mod_proxy_ftp: Use of uninitialized value with malicious backend FTP
     server. [Eric Covener]

  *) SECURITY: CVE-2020-1927 (cve.mitre.org)
     rewrite, core: Set PCRE_DOTALL flag by default to avoid unpredictable
     matches and substitutions with encoded line break characters.
     The fix for CVE-2019-10098 was not effective.  [Ruediger Pluem]

  *) mod_proxy_http: Fix the forwarding of requests with content body when a
     balancer member is unavailable; the retry on the next member was issued
     with an empty body (regression introduced in 2.4.41). PR63891.
     [Yann Ylavic]

  *) core: Use a temporary file when writing the pid file, avoiding
     startup failure if an empty pidfile is left over from a
     previous crashed or aborted invocation of httpd.  PR 63140.
     [Nicolas Carrier <carrier.nicolas0 gmail.com>, Joe Orton]

  *) mod_http2: Fixes issue where mod_unique_id would generate non-unique request
     identifier under load, see <https://github.com/icing/mod_h2/issues/195>.
     [Michael Kaufmann, Stefan Eissing]

  *) mod_proxy_hcheck: Allow healthcheck expressions to use %{Content-Type}.
     PR64140. [Renier Velazco <renier.velazco upr.edu>]

  *) mod_authz_groupfile: Drop AH01666 from loglevel "error" to "info".
     PR64172.

  *) mod_usertrack: Add CookieSameSite, CookieHTTPOnly, and CookieSecure
     to allow customization of the usertrack cookie. PR64077.
     [Prashant Keshvani <prashant2400 gmail.com>, Eric Covener]

  *) mod_proxy_ajp: Add "secret" parameter to proxy workers to implement legacy
     AJP13 authentication.  PR 53098. [Dmitry A. Bakshaev <dab1818 gmail com>]

  *) mpm_event: avoid possible KeepAliveTimeout off by -100 ms.
     [Eric Covener, Yann Ylavic]

  *) Add a config layout for OpenWRT. [Graham Leggett]

  *) Add support for cross compiling to apxs. If apxs is being executed from
     somewhere other than its target location, add that prefix to includes and
     library directories. Without this, apxs would fail to find config_vars.mk
     and exit. [Graham Leggett]

  *) mod_ssl: Disable client verification on ACME ALPN challenges. Fixes github
     issue mod_md#172 (https://github.com/icing/mod_md/issues/172).
     [Michael Kaufmann <mail michael-kaufmann.ch>, Stefan Eissing]

  *) mod_ssl: use OPENSSL_init_ssl() to initialise OpenSSL on versions 1.1+.
     [Graham Leggett]

  *) mod_ssl: Support use of private keys and certificates from an
     OpenSSL ENGINE via PKCS#11 URIs in SSLCertificateFile/KeyFile.
     [Anderson Sasaki <ansasaki redhat.com>, Joe Orton]

  *) mod_md:
     - Prefer MDContactEmail directive to ServerAdmin for registration. New directive
       thanks to Timothe Litt (@tlhackque).
     - protocol check for pre-configured "tls-alpn-01" challenge has been improved. It will now
       check all matching virtual hosts for protocol support. Thanks to @mkauf.
     - Corrected a check when OCSP stapling was configured for hosts
       where the responsible MDomain is not clear, by Michal Karm Babacek (@Karm).
     - Softening the restrictions where mod_md configuration directives may appear. This should
       allow for use in <If> and <Macro> sections. If all possible variations lead to the configuration
       you wanted in the first place, is another matter.
     [Michael Kaufmann <mail michael-kaufmann.ch>, Timothe Litt (@tlhackque),
      Michal Karm Babacek (@Karm), Stefan Eissing (@icing)]

  *) test: Added continuous testing with Travis CI.
     This tests various scenarios on Ubuntu with the full test suite.
     Architectures tested: amd64, s390x, ppc64le, arm64
     The tests pass successfully.
     [Luca Toscano, Joe Orton, Mike Rumph, and others]

  *) core: Be stricter in parsing of Transfer-Encoding headers.
     [ZeddYu <zeddyu.lu gmail.com>, Eric Covener]

  *) mod_ssl: negotiate the TLS protocol version per name based vhost
     configuration, when linked with OpenSSL-1.1.1 or later. The base vhost's
     SSLProtocol (from the first vhost declared on the IP:port) is now only
     relevant if no SSLProtocol is declared for the vhost or globally,
     otherwise the vhost or global value apply.  [Yann Ylavic]

  *) mod_cgi, mod_cgid: Fix a memory leak in some error cases with large script
     output.  PR 64096.  [Joe Orton]

  *) config: Speed up graceful restarts by using pre-hashed command table. PR 64066.
     [Giovanni Bechis <giovanni paclan.it>, Jim Jagielski]

  *) mod_systemd: New module providing integration with systemd.  [Jan Kaluza]

  *) mod_lua: Add r:headers_in_table, r:headers_out_table, r:err_headers_out_table,
     r:notes_table, r:subprocess_env_table as read-only native table alternatives
     that can be iterated over. [Eric Covener]

  *) mod_http2: Fixed rare cases where a h2 worker could deadlock the main connection.
     [Yann Ylavic, Stefan Eissing]

  *) mod_lua: Accept nil assignments to the exposed tables (r.subprocess_env,
     r.headers_out, etc) to remove the key from the table. PR63971.
     [Eric Covener]

  *) mod_http2: Fixed interaction with mod_reqtimeout. A loaded mod_http2 was disabling the
     ssl handshake timeouts. Also, fixed a mistake of the last version that made `H2Direct`
     always `on`, regardless of configuration. Found and reported by
     <Armin.Abfalterer@united-security-providers.ch> and
     <Marcial.Rion@united-security-providers.ch>. [Stefan Eissing]

  *) mod_http2: Multiple field length violations in the same request no longer cause
     several log entries to be written. [@mkauf]

  *) mod_ssl: OCSP does not apply to proxy mode.  PR 63679.
     [Lubos Uhliarik <luhliari redhat.com>, Yann Ylavic]

  *) mod_proxy_html, mod_xml2enc: Fix build issues with macOS due to r1864469
     [Jim Jagielski]

  *) mod_authn_socache: Increase the maximum length of strings that can be cached by
     the module from 100 to 256.  PR 62149 [<thorsten.meinl knime.com>]

  *) mod_proxy: Fix crash by resolving pool concurrency problems. PR 63503
     [Ruediger Pluem, Eric Covener]

  *) core: On Windows, fix a start-up crash if <IfFile ...> is used with a path that is not
     valid (For example, testing for a file on a flash drive that is not mounted)
     [Christophe Jaillet]

  *) mod_deflate, mod_brotli: honor "Accept-Encoding: foo;q=0" as per RFC 7231; which
     means 'foo' is "not acceptable".  PR 58158 [Chistophe Jaillet]

  *) mod_md v2.2.3:
     - Configuring MDCAChallenges replaces any previous existing challenge configuration. It
       had been additive before which was not the intended behaviour. [@mkauf]
     - Fixing order of ACME challenges used when nothing else configured. Code now behaves as
       documented for `MDCAChallenges`. Fixes #156. Thanks again to @mkauf for finding this.
     - Fixing a potential, low memory null pointer dereference [thanks to @uhliarik].
     - Fixing an incompatibility with a change in libcurl v7.66.0 that added unwanted
       "transfer-encoding" to POST requests. This failed in direct communication with
       Let's Encrypt boulder server. Thanks to @mkauf for finding and fixing. [Stefan Eissing]

  *) mod_md: Adding the several new features.
     The module offers an implementation of OCSP Stapling that can replace fully or
     for a limited set of domains the existing one from mod_ssl. OCSP handling
     is part of mod_md's monitoring and message notifications. If can be used
     for sites that do not have ACME certificates.
     The url for a CTLog Monitor can be configured. It is used in the server-status
     to link to the external status page of a certificate.
     The MDMessageCmd is called with argument "installed" when a new certificate
     has been activated on server restart/reload. This allows for processing of
     the new certificate, for example to applications that require it in different
     locations or formats.
     [Stefan Eissing]

  *) mod_proxy_balancer: Fix case-sensitive referer check related to CSRF/XSS
     protection. PR 63688. [Armin Abfalterer <a.abfalterer gmail.com>]

Changes with Apache 2.4.41

  *) SECURITY: CVE-2019-10097 (cve.mitre.org)
     mod_remoteip: Fix stack buffer overflow and NULL pointer deference
     when reading the PROXY protocol header.  [Joe Orton,
     Daniel McCarney <cpu letsencrypt.org>]

  *) SECURITY: CVE-2019-9517 (cve.mitre.org)
     mod_http2: a malicious client could perform a DoS attack by flooding
        a connection with requests and basically never reading responses
        on the TCP connection. Depending on h2 worker dimensioning, it was
        possible to block those with relatively few connections. [Stefan Eissing]

  *) SECURITY: CVE-2019-10098 (cve.mitre.org)
     rewrite, core: Set PCRE_DOTALL flag by default to avoid unpredictable
     matches and substitutions with encoded line break characters.
     [Yann Ylavic]

  *) SECURITY: CVE-2019-10092 (cve.mitre.org)
     Remove HTML-escaped URLs from canned error responses to prevent misleading
     text/links being displayed via crafted links. [Eric Covener]

  *) SECURITY: CVE-2019-10082 (cve.mitre.org)
     mod_http2: Using fuzzed network input, the http/2 session
     handling could be made to read memory after being freed,
     during connection shutdown. [Stefan Eissing]

  *) SECURITY: CVE-2019-10081 (cve.mitre.org)
     mod_http2: HTTP/2 very early pushes, for example configured with "H2PushResource",
        could lead to an overwrite of memory in the pushing request's pool,
        leading to crashes. The memory copied is that of the configured push
        link header values, not data supplied by the client. [Stefan Eissing]

  *) mod_proxy_balancer: Improve balancer-manager protection against
     XSS/XSRF attacks from trusted users.  [Joe Orton,
     Niels Heinen <heinenn google.com>]

  *) mod_session: Introduce SessionExpiryUpdateInterval which allows to
     configure the session/cookie expiry's update interval. PR 57300.
     [Paul Spangler <paul.spangler ni.com>]

  *) modules/filters: Fix broken compilation when using old GCC (<4.2.x).
     PR 63633.  [Rainer Jung, Joe Orton]

  *) mod_ssl: Fix startup failure in 2.4.40 with SSLCertificateChainFile
     configured for a domain managed by mod_md.  [Stefan Eissing]

Changes with Apache 2.4.40

  *) core, mod_rewrite: Set PCRE_DOTALL by default. Revert via
     RegexDefaultOptions -DOTALL [Yann Ylavic]

  *) core: Remove request details from built-in error documents [Eric Covener]

  *) mod_http2: core setting "LimitRequestFieldSize" is not additionally checked on
     merged header fields, just as HTTP/1.1 does. [Stefan Eissing, Michael Kaufmann]

  *) mod_http2: fixed a bug that prevented proper stream cleanup when connection
     throttling was in place. Stream resets by clients on streams initiated by them
     are counted as possible trigger for throttling. [Stefan Eissing]

  *) mod_http2/mpm_event: Fixes the behaviour when a HTTP/2 connection has nothing
     more to write with streams ongoing (flow control block). The timeout waiting
     for the client to send WINODW_UPDATE was incorrectly KeepAliveTimeout and not
     Timeout as it should be. Fixes PR 63534. [Yann Ylavic, Stefan Eissing]

  *) mod_proxy_balancer: Load balancer required byrequests when bytraffic chosen.
     PR 62372. [Jim Jagielski]

  *) mod_proxy_hcheck: Create the configuration for mod_proxy_hcheck
     when used in BalancerMember. PR 60757. [Jean-Frederic Clere]

  *) mod_proxy_hcheck: Mute extremely frequent debug message. [Yann Ylavic]

  *) mod_ssl/mod_md: reversing dependency by letting mod_ssl offer hooks for
     adding certificates and keys to a virtual host. An additional hook allows
     answering special TLS connections as used in ACME challenges.
     Adding 2 new hooks for init/get of OCSP stapling status information when
     other modules want to provide those. Falls back to own implementation with
     same behaviour as before.
     [Stefan Eissing]

  *) mod_md: new features
     - protocol
       - supports the ACMEv2 protocol. It is the default and will be used on the next
         certificate renewal, unless another "MDCertificateAuthority" is configured
       - ACMEv2 endpoints use the GET via empty POST way of accessing resources, see
         announcement by Let's Encrypt:
         https://community.letsencrypt.org/t/acme-v2-scheduled-deprecation-of-unauthenticated-resource-gets/74380
     - challenges
       - new challenge method 'tls-alpn-01' implemented
       - challenge type 'tls-sni-01' has been removed as CAs do not offer this any longer
       - supports command configuration to setup/teardown 'dns-01' challenges
       - supports wildcard certificates when dns challenges are configured
     - status information and monitoring
       - a domain exposes its status at https://<domain>/.httpd/certificate-status
       - Managed Domains are now in Apache's 'server-status' page
       - A new handler 'md-status' exposes verbose status information in JSON format
     - new directives
       - "MDCertificateFile" and "MDCertificateKeyFile" to configure a
         Managed Domain that uses static files. Auto-renewal is turned off for those.
       - "MDMessageCmd" that is invoked on several events: 'renewed', 'expiring' and
         'errored'.
       - "MDWarnWindow" directive to configure when expiration warnings shall be issued.
     [Stefan Eissing]

  *) mod_mime_magic: Fix possible corruption of returned strings.
     [Christophe Jaillet]

  *) Default "conf/magic": Fix pattern for "audio/x-wav" for WAV files,
     remove "audio/unknown" pattern for other RIFF files.
     [Àngel Ollé Blázquez <aollebla redhat.com>]

  *) mod_proxy_http2: fixing a potential NULL pointer use in logging.
     [Christophe Jaillet, Dr Silvio Cesare InfoSect]

  *) mod_dav: Reduce the amount of memory needed when doing PROPFIND's on large
     collections by improving the memory management. [Joe Orton, Ruediger Pluem]

  *) mod_proxy_http2: adding support for handling trailers in both directions.
     PR 63502. [Stefan Eissing]

  *) mod_proxy_http: forward 100-continue, and minimize race conditions when
     reusing backend connections. PR 60330. [Yann Ylavic, Jean-Frederic Clere]

  *) mod_proxy_balancer: Fix some HTML syntax issues.  [Christophe Jaillet]

  *) When using mod_status with the Event MPM, report the number of requests
     associated with an active connection in the "ACC" field. Previously
     zero was always reported with this MPM.  PR60647. [Eric Covener]

  *) mod_http2: remove the no longer existing h2_ngn_shed.c from Cmake.
     [Stefan Eissing]

  *) mod_proxy/ssl: Proxy SSL client certificate configuration and other proxy
     SSL configurations broken inside <Proxy> context.  PR 63430.
     [Ruediger Pluem, Yann Ylavic]

  *) mod_proxy: allow SSLProxyCheckPeer* usage for all proxy modules.
     PR 61857.  [Markus Gausling <markusgausling googlemail.com>, Yann Ylavic]

  *) mod_reqtimeout: Fix default rates missing (not applied) in 2.4.39.
     PR 63325. [Yann Ylavic]

  *) mod_info: Fix output of server settings for PIPE_BUF in mod_info in
     the rare case that PIPE_BUF is defined. [Rainer Jung]

  *) mod_md: Store permissions are enforced on file creation, enforcing restrictions in
     spite of umask. Fixes <https://github.com/icing/mod_md/issues/117>. [Stefan Eissing]

Changes with Apache 2.4.39

  *) SECURITY: CVE-2019-0197 (cve.mitre.org)
     mod_http2: fixes a possible crash when HTTP/2 was enabled for a http:
     host or H2Upgrade was enabled for h2 on a https: host. An Upgrade
     request from http/1.1 to http/2 that was not the first request on a
     connection could lead to a misconfiguration and crash. Servers that
     never enabled the h2 protocol or only enabled it for https: and
     did not set "H2Upgrade on" are unaffected by this issue.
     [Stefan Eissing]

  *) SECURITY: CVE-2019-0196 (cve.mitre.org)
     mod_http2: using fuzzed network input, the http/2 request
     handling could be made to access freed memory in string
     comparison when determining the method of a request and
     thus process the request incorrectly. [Stefan Eissing]

  *) SECURITY: CVE-2019-0211 (cve.mitre.org)
     MPMs unix: Fix a local privilege escalation vulnerability by not
     maintaining each child's listener bucket number in the scoreboard,
     preventing unprivileged code like scripts run by/on the server (e.g. via
     mod_php) from modifying it persistently to abuse the privileged main
     process.  [Charles Fol <folcharles gmail.com>, Yann Ylavic]

  *) SECURITY: CVE-2019-0217 (cve.mitre.org)
     mod_auth_digest: Fix a race condition checking user credentials which
     could allow a user with valid credentials to impersonate another,
     under a threaded MPM.  PR 63124.  [Simon Kappel <simon.kappel axis.com>]

  *) SECURITY: CVE-2019-0215 (cve.mitre.org)
     mod_ssl: Fix access control bypass for per-location/per-dir client
     certificate verification in TLSv1.3.

  *) SECURITY: CVE-2019-0220 (cve.mitre.org)
     Merge consecutive slashes in URL's. Opt-out with
     `MergeSlashes OFF`. [Eric Covener]

  *) mod_proxy/ssl: Cleanup per-request SSL configuration anytime a backend
     connection is recycled/reused to avoid a possible crash with some SSLProxy
     configurations in <Location> or <Proxy> context. PR 63256. [Yann Ylavic]

  *) mod_log_config: Support %{c}h for conn-hostname, %h for useragent_host
     PR 55348

  *) mod_socache_redis: Support for Redis as socache storage provider.

  *) core: new configuration option 'MergeSlashes on|off' that controls handling of
     multiple, consecutive slash ('/') characters in the path component of the request URL.
     [Eric Covener]

  *) mod_http2: when SSL renegotiation is inhibited and a 403 ErrorDocument is
     in play, the proper HTTP/2 stream reset did not trigger with H2_ERR_HTTP_1_1_REQUIRED.
     Fixed. [Michael Kaufmann]

  *) mod_http2: new configuration directive: `H2Padding numbits` to control
     padding of HTTP/2 payload frames. 'numbits' is a number from 0-8,
     controlling the range of padding bytes added to a frame. The actual number
     added is chosen randomly per frame. This applies to HEADERS, DATA and PUSH_PROMISE
     frames equally. The default continues to be 0, e.g. no padding. [Stefan Eissing]

  *) mod_http2: ripping out all the h2_req_engine internal features now that mod_proxy_http2
     has no more need for it. Optional functions are still declared but no longer implemented.
     While previous mod_proxy_http2 will work with this, it is recommended to run the matching
     versions of both modules. [Stefan Eissing]

  *) mod_proxy_http2: changed mod_proxy_http2 implementation and fixed several bugs which
     resolve PR63170. The proxy module does now a single h2 request on the (reused)
     connection and returns. [Stefan Eissing]

  *) mod_http2/mod_proxy_http2: proxy_http2 checks correct master connection aborted status
     to trigger immediate shutdown of backend connections. This is now always signalled
     by mod_http2 when the the session is being released.
     proxy_http2 now only sends a PING frame to the backend when there is not already one
     in flight. [Stefan Eissing]

  *) mod_proxy_http2: fixed an issue where a proxy_http2 handler entered an infinite
     loop when encountering certain errors on the backend connection.
     See <https://bz.apache.org/bugzilla/show_bug.cgi?id=63170>. [Stefan Eissing]

  *) mod_http2: Configuration directives H2Push and H2Upgrade can now be specified per
     Location/Directory, e.g. disabling PUSH for a specific set of resources. [Stefan Eissing]

  *) mod_http2: HEAD requests to some module such as mod_cgid caused the stream to
     terminate improperly and cause a HTTP/2 PROTOCOL_ERROR.
     Fixes <https://github.com/icing/mod_h2/issues/167>. [Michael Kaufmann]

  *) http: Fix possible empty response with mod_ratelimit for HEAD requests.
     PR 63192. [Yann Ylavic]

  *) mod_cache_socache: Avoid reallocations and be safe with outgoing data
     lifetime. [Yann Ylavic]

  *) mod_http2: enable re-use of slave connections again. Fixed slave connection
     keepalives counter. [Stefan Eissing]

  *) mod_reqtimeout: Allow to configure (TLS-)handshake timeouts.
     PR 61310. [Yann Ylavic]

  *) core: Split out the ability to parse wildcard files and directories
     from the Include/IncludeOptional directives into a generic set of
     functions ap_dir_nofnmatch() and ap_dir_fnmatch(). [Graham Leggett]

  *) mod_proxy_wstunnel: Fix websocket proxy over UDS.
     PR 62932 <pavel dcmsys.com>

  *) mod_ssl: Don't unset FIPS mode on restart unless it's forced by
     configuration (SSLFIPS on) and not active by default in OpenSSL.
     PR 63136. [Yann Ylavic]

Changes with Apache 2.4.38

  *) SECURITY: CVE-2018-17199 (cve.mitre.org)
     mod_session: mod_session_cookie does not respect expiry time allowing
     sessions to be reused.  [Hank Ibell]

  *) SECURITY: CVE-2018-17189 (cve.mitre.org)
     mod_http2: fixes a DoS attack vector. By sending slow request bodies
     to resources not consuming them, httpd cleanup code occupies a server
     thread unnecessarily. This was changed to an immediate stream reset
     which discards all stream state and incoming data.  [Stefan Eissing]

  *) SECURITY: CVE-2019-0190 (cve.mitre.org)
     mod_ssl: Fix infinite loop triggered by a client-initiated
     renegotiation in TLSv1.2 (or earlier) with OpenSSL 1.1.1 and
     later.  PR 63052.  [Joe Orton]

  *) mod_ssl: Clear retry flag before aborting client-initiated renegotiation.
     PR 63052 [Joe Orton]

  *) mod_negotiation: Treat LanguagePriority as case-insensitive to match
     AddLanguage behavior and HTTP specification. PR 39730 [Christophe Jaillet]

  *) mod_md: incorrect behaviour when synchronizing ongoing ACME challenges
     have been fixed. [Michael Kaufmann, Stefan Eissing]

  *) mod_setenvif: We can have expressions that become true if a regex pattern
     in the expression does NOT match. In this case val is NULL
     and we should just set the value for the environment variable
     like in the pattern case. [Ruediger Pluem]

  *) mod_session: Always decode session attributes early. [Hank Ibell]

  *) core: Incorrect values for environment variables are substituted when
     multiple environment variables are specified in a directive. [Hank Ibell]

  *) mod_rewrite: Only create the global mutex used by "RewriteMap prg:" when
     this type of map is present in the configuration.  PR62311.
     [Hank Ibell <hwibell gmail.com>]

  *) mod_dav: Fix invalid Location header when a resource is created by
     passing an absolute URI on the request line [Jim Jagielski]

  *) mod_session_cookie: avoid duplicate Set-Cookie header in the response.
     [Emmanuel Dreyfus <manu@netbsd.org>, Luca Toscano]

  *) mod_ssl: clear *SSL errors before loading certificates and checking
     afterwards. Otherwise errors are reported when other SSL using modules
     are in play. Fixes PR 62880. [Michael Kaufmann]

  *) mod_ssl: Fix the error code returned in an error path of
     'ssl_io_filter_handshake()'. This messes-up error handling performed
     in 'ssl_io_filter_error()' [Yann Ylavic]

  *) mod_ssl: Fix $HTTPS definition for "SSLEngine optional" case, and fix
     authz provider so "Require ssl" works correctly in HTTP/2.
     PR 61519, 62654.  [Joe Orton, Stefan Eissing]

  *) mod_proxy: If ProxyPassReverse is used for reverse mapping of relative
     redirects, subsequent ProxyPassReverse statements, whether they are
     relative or absolute, may fail.  PR 60408.  [Peter Haworth <pmh1wheel gmail.com>]

  *) mod_lua: Now marked as a stable module [https://s.apache.org/Xnh1]

Changes with Apache 2.4.37

  *) mod_ssl: Fix HTTP/2 failures when using OpenSSL 1.1.1. [Rainer Jung]

  *) mod_ssl: Fix crash during SSL renegotiation with OptRenegotiate set,
     when client certificates are available from the original handshake
     but were originally not verified and should get verified now.
     This is a regression in 2.4.36 (unreleased). [Ruediger Pluem]

  *) mod_ssl: Correctly merge configurations that have client certificates set
     by SSLProxyMachineCertificate{File|Path}. [Ruediger Pluem]

Changes with Apache 2.4.36

  *) mod_brotli, mod_deflate: Restore the separate handling of 304 Not Modified
     responses. Regression introduced in 2.4.35.

  *) mod_proxy_scgi, mod_proxy_uwsgi: improve error handling when sending the
     body of the response. [Jim Jagielski]

  *) mpm_event: Stop issuing AH00484 "server reached MaxRequestWorkers..." when
     there are still idle threads available. When there are less idle threads than
     MinSpareThreads, issue new one-time message AH10159. Matches worker MPM.
     [Eric Covener]

  *) mod_http2: adding defensive code for stream EOS handling, in case the request handler
     missed to signal it the normal way (eos buckets). Addresses github issues
     https://github.com/icing/mod_h2/issues/164, https://github.com/icing/mod_h2/issues/167
     and https://github.com/icing/mod_h2/issues/170. [Stefan Eissing]

  *) ab: Add client certificate support.  PR 55774.  [Graham Leggett]

  *) ab: Disable printing temp key for OpenSSL before
     version 1.0.2. SSL_get_server_tmp_key is not available
     there. [Rainer Jung]

  *) mod_ssl: Fix a regression that the configuration settings for verify mode
     and verify depth were taken from the frontend connection in case of
     connections by the proxy to the backend. PR 62769. [Ruediger Pluem]

  *) MPMs: Initialize all runtime/asynchronous objects on a dedicated pool and
     before signals handling to avoid lifetime issues on restart or shutdown.
     PR 62658. [Yann Ylavic]

  *) mod_ssl: Add support for OpenSSL 1.1.1 and TLSv1.3.  TLSv1.3 has
     behavioural changes compared to v1.2 and earlier; client and
     configuration changes should be expected.  SSLCipherSuite is
     enhanced for TLSv1.3 ciphers, but applies at vhost level only.
     [Stefan Eissing, Yann Ylavic, Ruediger Pluem, Joe Orton]

  *) mod_auth_basic: Be less tolerant when parsing the credencial. Only spaces
     should be accepted after the authorization scheme. \t are also tolerated.
     [Christophe Jaillet]

  *) mod_socache_redis: New socache submodule provider to allow use
     of Redis as storage backend. [Jim Jagielski]

  *) mod_proxy_hcheck: Fix issues with interval determination. PR 62318
     [Jim Jagielski]

  *) mod_proxy_hcheck: Fix issues with TCP health checks. PR 61499
     [Dominik Stillhard <dominik.stillhard united-security-providers.ch>]

  *) mod_proxy_hcheck: take balancer's SSLProxy* directives into account.
     [Jim Jagielski]

  *) mod_status, mod_echo: Fix the display of client addresses.
    They were truncated to 31 characters which is not enough for IPv6 addresses.
    This is done by deprecating the use of the 'client' field and using
    the new 'client64' field in worker_score.
    PR 54848 [Bernhard Schmidt <berni birkenwald de>, Jim Jagielski]

Changes with Apache 2.4.35

  *) http: Enforce consistently no response body with both 204 and 304
     statuses.  [Yann Ylavic]

  *) mod_status: Cumulate CPU time of exited child processes in the
     "cu" and "cs" values. Add CPU time of the parent process to the
     "c" and "s" values.
     [Rainer Jung]

  *) mod_proxy: Improve the balancer member data shown in mod_status when
     "ProxyStatus" is "On": add "busy" count and show byte counts in
     auto mode always in units of kilobytes.  [Rainer Jung]

  *) mod_status: Add cumulated response duration time in milliseconds.
     [Rainer Jung]

  *) mod_status: Complete the data shown for async MPMs in "auto" mode.
     Added number of processes, number of stopping processes and number
     of busy and idle workers.  [Rainer Jung]

  *) mod_ratelimit: Don't interfere with "chunked" encoding, fixing regression
     introduced in 2.4.34.  PR 62568.  [Yann Ylavic]

  *) mod_proxy: Remove load order and link dependency between mod_lbmethod_*
     modules and mod_proxy. PR 62557. [Ruediger Pluem, William Rowe]

  *) Allow the argument to <IfFile>, <IfDefine>, <IfSection>, <IfDirective>,
     and <IfModule> to be quoted.  This is primarily for the benefit of
     <IfFile>. [Eric Covener]

  *) mod_watchdog: Correct some log messages.  [Rainer Jung]

  *) mod_md: When the last domain name from an MD is moved to another one,
     that now empty MD gets moved to the store archive. PR 62572.
     [Stefan Eissing]

  *) mod_ssl: Fix merging of SSLOCSPOverrideResponder.  [Jeff Trawick,
     [Frank Meier <frank meier ergon.ch>]

  *) mod_proxy_balancer: Restore compatibility with APR 1.4.  [Joe Orton]

Changes with Apache 2.4.34

  *) SECURITY: CVE-2018-8011 (cve.mitre.org)
     mod_md: DoS via Coredumps on specially crafted requests

  *) SECURITY: CVE-2018-1333 (cve.mitre.org)
     mod_http2: DoS for HTTP/2 connections by specially crafted requests

  *) Introduce zh-cn and zh-tw (simplified and traditional Chinese) error
     document translations. [CodeingBoy, popcorner]

  *) event: avoid possible race conditions with modules on the child pool.
     [Stefan Fritsch]

  *) mod_proxy: Fix a corner case where the ProxyPassReverseCookieDomain or
     ProxyPassReverseCookiePath directive could fail to update correctly
     'domain=' or 'path=' in the 'Set-Cookie' header.  PR 61560.
     [Christophe Jaillet]

  *) mod_ratelimit: fix behavior when proxing content. PR 62362.
     [Luca Toscano, Yann Ylavic]

  *) core: Re-allow '_' (underscore) in hostnames.
     [Eric Covener]

  *) mod_authz_core: If several parameters are used in a AuthzProviderAlias
     directive, if these parameters are not enclosed in quotation mark, only
     the first one is handled. The other ones are silently ignored.
     Add a message to warn about such a spurious configuration.
     PR 62469 [Hank Ibell <hwibell gmail.com>, Christophe Jaillet]

  *) mod_md: improvements and bugfixes
     - MDNotifyCmd now takes additional parameter that are passed on to the called command.
     - ACME challenges have better checks for interference with other modules
     - ACME challenges are only handled for domains managed by the module, allowing
       other ACME clients to operate for other domains in the server.
     - better libressl integration

  *) mod_proxy_wstunnel: Add default schema ports for 'ws' and 'wss'.
     PR 62480. [Lubos Uhliarik <luhliari redhat.com>}

  *) logging: Some early logging-related startup messages could be lost
     when using syslog for the global ErrorLog. [Eric Covener]

  *) mod_cache: Handle case of an invalid Expires header value RFC compliant
     like the case of an Expires time in the past: allow to overwrite the
     non-caching decision using CacheStoreExpired and respect Cache-Control
     "max-age" and "s-maxage".  [Rainer Jung]

  *) mod_xml2enc: Fix forwarding of error metadata/responses. PR 62180.
     [Micha Lenk <micha lenk.info>, Yann Ylavic]

  *) mod_proxy_http: Fix response header thrown away after the previous one
     was considered too large and truncated. PR 62196. [Yann Ylavic]

  *) core: Add and handle AP_GETLINE_NOSPC_EOL flag for ap_getline() family
     of functions to consume the end of line when the buffer is exhausted.
     PR 62198. [Yann Ylavic]

  *) mod_proxy_http: Add new worker parameter 'responsefieldsize' to
     allow maximum HTTP response header size to be increased past 8192
     bytes.  PR 62199.  [Hank Ibell <hwibell gmail.com>]

  *) mod_ssl: Extend SSLOCSPEnable with mode 'leaf' that only checks the leaf
     of a certificate chain.  PR62112.
     [Ricardo Martin Camarero <rickyepoderi yahoo.es>]

  *) http: Fix small memory leak per request when handling persistent
     connections.  [Ruediger Pluem, Joe Orton]

  *) mod_proxy_html: Fix variable interpolation and memory allocation failure
     in ProxyHTMLURLMap.  PR 62344.  [Ewald Dieterich <ewald mailbox.org>]

  *) mod_remoteip: Fix RemoteIP{Trusted,Internal}ProxyList loading broken by 2.4.30.
     PR 62220.  [Chritophe Jaillet, Yann Ylavic]

  *) mod_remoteip: When overriding the useragent address from X-Forwarded-For,
     zero out what had been initialized as the connection-level port.  PR59931.
     [Hank Ibell <hwibell gmail.com>]

  *) core: In ONE_PROCESS/debug mode, cleanup everything when exiting.
     [Yann Ylavic]

  *) mod_proxy_balancer: Add hot spare member type and corresponding flag (R).
     Hot spare members are used as drop-in replacements for unusable workers
     in the same load balancer set. This differs from hot standbys which are
     only used when all workers in a set are unusable. PR 61140. [Jim Riggs]

  *) suexec: Add --enable-suexec-capabilites support on Linux, to use
     setuid/setgid capability bits rather than a setuid root binary.
     [Joe Orton]

  *) suexec: Add support for logging to syslog as an alternative to
     logging to a file; use --without-suexec-logfile --with-suexec-syslog.
     [Joe Orton]

  *) mod_ssl: Restore 2.4.29 behaviour in SSL vhost merging/enabling
     which broke some rare but previously-working configs.  [Joe Orton]

  *) core, log: improve sanity checks for the ErrorLog's syslog config, and
     explicitly allow only lowercase 'syslog' settings. PR 62102
     [Luca Toscano, Jim Riggs, Christophe Jaillet]

  *) mod_http2: accurate reporting of h2 data input/output per request via
     mod_logio. Fixes an issue where output sizes where counted n-times on
     reused slave connections.  [Stefan Eissing]
     See github issue: https://github.com/icing/mod_h2/issues/158

  *) mod_http2: Fix unnecessary timeout waits in case streams are aborted.
     [Stefan Eissing]

  *) mod_http2: restoring the v1.10.16 keepalive timeout behaviour of mod_http2.
     [Stefan Eissing]

  *) mod_proxy: Do not restrict the maximum pool size for backend connections
     any longer by the maximum number of threads per process and use a better
     default if mod_http2 is loaded.
     [Yann Ylavic, Ruediger Pluem, Stefan Eissing, Gregg Smith]

  *) mod_slotmem_shm: Add generation number to shm filename to fix races
     with graceful restarts. PRs 62044 and 62308.  [Jim Jagielski, Yann Ylavic]

  *) core: Preserve the original HTTP request method in the '%<m' LogFormat
     when an path-based ErrorDocument is used.  PR 62186.
     [Micha Lenk <micha lenk.info>]

  *) mod_remoteip: make proxy-protocol work on slave connections, e.g. in
     HTTP/2 requests.  [Stefan Eissing]
     See also https://github.com/roadrunner2/mod-proxy-protocol/issues/6

  *) mod_ssl: Fix merging of proxy SSL context outside <Proxy> sections,
     regression introduced in 2.4.30. PR 62232. [Rainer Jung, Yann Ylavic]

  *) mod_md: Fix compilation with OpenSSL before version 1.0.2.  [Rainer Jung]

  *) mod_dumpio: do nothing below log level TRACE7.  [Yann Ylavic]

  *) mod_remoteip: Restore compatibility with APR 1.4 (apr_sockaddr_is_wildcard).
     [Eric Covener]

  *) core: On ECBDIC platforms, some errors related to oversized headers
     may be misreported or be logged as ASCII escapes.  PR 62200
     [Hank Ibell <hwibell gmail.com>]

  *) mod_ssl: Fix cmake-based build.  PR 62266.  [Rainer Jung]

  *) core: Add <IfFile>, <IfDirective> and <IfSection> conditional
     section containers.  [Eric Covener, Joe Orton]

  *) rotatelogs: Add -D option to create parent directories.  PR 46669.
     [Philippe Lantin <plantin cobaltgroup.com>, Ben Reser, Rainer Jung]

Changes with Apache 2.4.33

  *) core: Fix request timeout logging and possible crash for error_log hooks.
     [Yann Ylavic]

  *) mod_slomem_shm: Fix failure to create balancers's slotmems in Windows MPM,
     where children processes need to attach them instead since they are owned
     by the parent process already.  [Yann Ylavic]

  *) ab: try all destination socket addresses returned by
     apr_sockaddr_info_get instead of failing on first one when not available.
     Needed for instance if localhost resolves to both ::1 and 127.0.0.1
     e.g. if both are in /etc/hosts.  [Jan Kaluza]

  *) ab: Use only one connection to determine working destination socket
     address.  [Jan Kaluza]

  *) ab: LibreSSL doesn't have or require Windows applink.c.  [Gregg L. Smith]

  *) htpasswd/htdigest: Disable support for bcrypt on EBCDIC platforms.
     apr-util's bcrypt implementation doesn't tolerate EBCDIC.  [Eric Covener]

  *) htpasswd/htdbm: report the right limit when get_password() overflows.
     [Yann Ylavic]

  *) htpasswd: Don't fail in -v mode if password file is unwritable.
     PR 61631.  [Joe Orton]

  *) htpasswd: don't point to (unused) stack memory on output
     to make static analysers happy.  PR 60634.
     [Yann Ylavic, reported by shqking and Zhenwei Zou]

Changes with Apache 2.4.32

  *) mod_access_compat: Fail if a comment is found in an Allow or Deny
     directive.  [Jan Kaluza]

  *) mod_authz_host: Ignore comments after "Require host", logging a
     warning, or logging an error if the line is otherwise empty.
     [Jan Kaluza, Joe Orton]

  *) rotatelogs: Fix expansion of %Z in localtime (-l) mode, and fix
     Y2K38 bug.  [Joe Orton]

  *) mod_ssl: Support SSL DN raw variable extraction without conversion
     to UTF-8, using _RAW suffix on variable names.  [Joe Orton]

  *) ab: Fix https:// connection failures (regression in 2.4.30); fix
     crash generating CSV output for large -n.  [Joe Orton, Jan Kaluza]

Changes with Apache 2.4.31 (not released)

  *) mod_proxy_fcgi: Add the support for mod_proxy's flushpackets and flushwait
     parameters. [Luca Toscano, Ruediger Pluem, Yann Ylavic]

  *) mod_ldap: Avoid possible crashes, hangs, and busy loops due to
     improper merging of the cache lock in vhost config.
     PR 43164 [Eric Covener]

  *) mpm_event: Do lingering close in worker(s).  [Yann Ylavic]

  *) mpm_queue: Put fdqueue code in common for MPMs event and worker.
     [Yann Ylavic]

Changes with Apache 2.4.30 (not released)

  *) SECURITY: CVE-2017-15710 (cve.mitre.org)
     Out of bound write in mod_authnz_ldap with AuthLDAPCharsetConfig enabled
     [Eric Covener, Luca Toscano, Yann Ylavic]

  *) SECURITY: CVE-2018-1283 (cve.mitre.org)
     mod_session: CGI-like applications that intend to read from mod_session's
     'SessionEnv ON' could be fooled into reading user-supplied data instead.
     [Yann Ylavic]

  *) SECURITY: CVE-2018-1303 (cve.mitre.org)
     mod_cache_socache: Fix request headers parsing to avoid a possible crash
     with specially crafted input data.  [Ruediger Pluem]

  *) SECURITY: CVE-2018-1301 (cve.mitre.org)
     core: Possible crash with excessively long HTTP request headers.
     Impractical to exploit with a production build and production LogLevel.
     [Yann Ylavic]

  *) SECURITY: CVE-2017-15715 (cve.mitre.org)
     core: Configure the regular expression engine to match '$' to the end of
     the input string only, excluding matching the end of any embedded
     newline characters. Behavior can be changed with new directive
     'RegexDefaultOptions'. [Yann Ylavic]

  *) SECURITY: CVE-2018-1312 (cve.mitre.org)
     mod_auth_digest: Fix generation of nonce values to prevent replay
     attacks across servers using a common Digest domain. This change
     may cause problems if used with round robin load balancers. PR 54637
     [Stefan Fritsch]

  *) SECURITY: CVE-2018-1302 (cve.mitre.org)
     mod_http2: Potential crash w/ mod_http2.
     [Stefan Eissing]

  *) mod_proxy: Provide an RFC1035 compliant version of the hostname in the
     proxy_worker_shared structure. PR62085 [Graham Leggett]

  *) mod_proxy: Worker schemes and hostnames which are too large are no
     longer fatal errors; it is logged and the truncated values are stored.
     [Jim Jagielski]

  *) mod_proxy: Allow setting options to globally defined balancer from
     ProxyPass used in VirtualHost. Balancers are now merged using the new
     merge_balancers method which merges the balancers options.  [Jan Kaluza]

  *) logresolve: Fix incorrect behavior or segfault if -c flag is used
     Fixes: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=823259
     [Stefan Fritsch]

  *) mod_remoteip: Add support for PROXY protocol (code donated by Cloudzilla).
     Add ability for PROXY protocol processing to be optional to donated code.
     See also: http://www.haproxy.org/download/1.5/doc/proxy-protocol.txt
     [Cloudzilla/roadrunner2@GitHub, Jim Jagielski, Daniel Ruggeri]

  *) mod_proxy, mod_ssl: Handle SSLProxy* directives in <Proxy> sections,
     allowing per backend TLS configuration.  [Yann Ylavic]

  *) mod_proxy_uwsgi: Add in UWSGI proxy (sub)module. [Roberto De Ioris,
     Jim Jagielski]

  *) mod_proxy_balancer,mod_slotmem_shm: Rework SHM reuse/deletion to not
     depend on the number of restarts (non-Unix systems) and preserve shared
     names as much as possible on configuration changes for SHMs and persisted
     files.  PR 62044.  [Yann Ylavic, Jim Jagielski]

  *) mod_http2: obsolete code removed, no more events on beam pool destruction,
     discourage content encoders on http2-status response (where they do not work).
     [Stefan Eissing]

  *) mpm_event: Let the listener thread do its maintenance job on resources
     shortage.  PR 61979.  [Yann Ylavic]

  *) mpm_event: Wakeup the listener to re-enable listening sockets.
     [Yann Ylavic]

  *) mod_ssl: The SSLCompression directive will now give an error if used
     with an OpenSSL build which does not support any compression methods.
     [Joe Orton]

  *) mpm_event,worker: Mask signals for threads created by modules in child
     init, so that they don't receive (implicitly) the ones meant for the MPM.
     PR 62009. [Armin Abfalterer <a.abfalterer gmail com>, Yann Ylavic]

  *) mod_md: new experimental, module for managing domains across virtual hosts,
     implementing the Let's Encrypt ACMEv1 protocol to signup and renew
     certificates. Please read the modules documentation for further instructions
     on how to use it. [Stefan Eissing]

  *) mod_proxy_html: skip documents shorter than 4 bytes
     PR 56286 [Micha Lenk <micha lenk info>]

  *) core, mpm_event: Avoid a small memory leak of the scoreboard handle, for
     the lifetime of the connection, each time it is processed by MPM event.
     [Yann Ylavic]

  *) mpm_event: Update scoreboard status for KeepAlive state.  [Yann Ylavic]

  *) mod_ldap: Fix a case where a full LDAP cache would continually fail to
     purge old entries and log AH01323. PR61891.
     [Hendrik Harms <hendrik.harms gmail.com>]

  *) mpm_event: close connections not reported as handled by any module to
     avoid losing track of them and leaking scoreboard entries.  PR 61551.
     [Yann Ylavic]

  *) core: A signal received while stopping could have crashed the main
     process.  PR 61558.  [Yann Ylavic]

  *) mod_ssl: support for mod_md added. [Stefan Eissing]

  *) mod_proxy_html: process parsed comments immediately.
     Fixes bug (seen in the wild when used with IBM's HTTPD bundle)
     where parsed comments may be lost. [Nick Kew]

  *) mod_proxy_html: introduce doctype for HTML 5 [Nick Kew]

  *) mod_proxy_html: fix typo-bug processing "strict" vs "transitional"
     HTML/XHTML.  PR 56457  [Nick Kew]

  *) mpm_event: avoid a very unlikely race condition between the listener and
     the workers when the latter fails to add a connection to the pollset.
     [Yann Ylavic]

  *) core: silently ignore a not existent file path when IncludeOptional
     is used. PR 57585. [Alberto Murillo Silva <powerbsd yahoo.com>, Luca Toscano]

  *) mod_macro: fix usability of globally defined macros in .htaccess files.
     PR 57525.  [Jose Kahan <jose w3.org>, Yann Ylavic]

  *) mod_rewrite, core: add the Vary header when a condition evaluates to true
     and the related RewriteRule is used in a Directory context
     (triggering an internal redirect). [Luca Toscano]

  *) ab: Make the TLS layer aware that the underlying socket is nonblocking,
     and use/handle POLLOUT where needed to avoid busy IOs and recover write
     errors when appropriate.  [Yann Ylavic]

  *) ab: Keep reading nonblocking to exhaust TCP or SSL buffers when previous
     read was incomplete (the SSL case can cause the next poll() to timeout
     since data are buffered already).  PR 61301 [Luca Toscano, Yann Ylavic]

  *) mod_http2: avoid unnecessary data retrieval for a trace log. Allow certain
     information retrievals on null bucket beams where it makes sense. [Stefan Eissing]

Changes with Apache 2.4.29

  *) mod_unique_id: Use output of the PRNG rather than IP address and
     pid, avoiding sleep() call and possible DNS issues at startup,
     plus improving randomness for IPv6-only hosts.  [Jan Kaluza]

  *) mod_rewrite, core: Avoid the 'Vary: Host' response header when HTTP_HOST
     is used in a condition that evaluates to true. PR 58231 [Luca Toscano, Yann Ylavic]

  *) mod_http2: v0.10.12, removed optimization for mutex handling in bucket
     beams that could lead to assertion failure in edge cases.
     [Stefan Eissing]

  *) mod_proxy: Fix regression for non decimal loadfactor parameter introduced
     in 2.4.28.  [Jim Jagielski]

  *) mod_authz_dbd: fix a segmentation fault if AuthzDBDQuery is not set.
     PR 61546.  [Lubos Uhliarik <luhliari redhat.com>]

  *) mod_rewrite: Add support for starting External Rewriting Programs
     as non-root user on UNIX systems by specifying username and group
     name as third argument of RewriteMap directive.  [Jan Kaluza]

  *) core: Rewrite the Content-Length filter to avoid excessive memory
     consumption. Chunked responses will be generated in more cases
     than in previous releases.  PR 61222.  [Joe Orton, Ruediger Pluem]

  *) mod_ssl: Fix SessionTicket callback return value, which does seem to
     matter with OpenSSL 1.1. [Yann Ylavic]

Changes with Apache 2.4.28

  *) SECURITY: CVE-2017-9798 (cve.mitre.org)
     Corrupted or freed memory access. <Limit[Except]> must now be used in the
     main configuration file (httpd.conf) to register HTTP methods before the
     .htaccess files.  [Yann Ylavic]

  *) event: Avoid possible blocking in the listener thread when shutting down
     connections. PR 60956.  [Yann Ylavic]

  *) mod_speling: Don't embed referer data in a link in error page.
     PR 38923 [Nick Kew]

  *) htdigest: prevent a buffer overflow when a string exceeds the allowed max
     length in a password file. PR 61511.
     [Luca Toscano, Hanno Böck <hanno hboeck de>]

  *) mod_proxy: loadfactor parameter can now be a decimal number (eg: 1.25).
     [Jim Jagielski]

  *) mod_proxy_wstunnel: Allow upgrade to any protocol dynamically.
     PR 61142.

  *) mod_watchdog/mod_proxy_hcheck: Time intervals can now be specified
     down to the millisecond. Supports 'mi' (minute), 'ms' (millisecond),
     's' (second) and 'hr' (hour!) time suffixes. [Jim Jagielski]

  *) mod_http2: Fix for stalling when more than 32KB are written to a
     suspended stream.  [Stefan Eissing]

  *) build: allow configuration without APR sources.  [Jacob Champion]

  *) mod_ssl, ab: Fix compatibility with LibreSSL.  PR 61184.
     [Bernard Spil <brnrd freebsd.org>, Michael Schlenker <msc contact.de>,
      Yann Ylavic]

  *) core/log: Support use of optional "tag" in syslog entries.
     PR 60525. [Ben Rubson <ben.rubson gmail.com>, Jim Jagielski]

  *) mod_proxy: Fix ProxyAddHeaders merging.  [Joe Orton]

  *) core: Disallow multiple Listen on the same IP:port when listener buckets
     are configured (ListenCoresBucketsRatio > 0), consistently with the single
     bucket case (default), thus avoiding the leak of the corresponding socket
     descriptors on graceful restart.  [Yann Ylavic]

  *) event: Avoid listener periodic wake ups by using the pollset wake-ability
     when available.  PR 57399.  [Yann Ylavic, Luca Toscano]

  *) mod_proxy_wstunnel: Fix detection of unresponded request which could have
     led to spurious HTTP 502 error messages sent on upgrade connections.
     PR 61283.  [Yann Ylavic]

Changes with Apache 2.4.27

  *) SECURITY: CVE-2017-9789 (cve.mitre.org)
     mod_http2: Read after free. When under stress, closing many connections,
     the HTTP/2 handling code would sometimes access memory after it has been
     freed, resulting in potentially erratic behaviour.
     [Stefan Eissing]

  *) SECURITY: CVE-2017-9788 (cve.mitre.org)
     mod_auth_digest: Uninitialized memory reflection.  The value placeholder
     in [Proxy-]Authorization headers type 'Digest' was not initialized or
     reset before or between successive key=value assignments.
     [William Rowe]

  *) COMPATIBILITY: mod_lua: Remove the undocumented exported 'apr_table'
     global variable when using Lua 5.2 or later. This was exported as a
     side effect from luaL_register, which is no longer supported as of
     Lua 5.2 which deprecates pollution of the global namespace.
     [Rainer Jung]

  *) COMPATIBILITY: mod_http2: Disable and give warning when using Prefork.
     The server will continue to run, but HTTP/2 will no longer be negotiated.
     [Stefan Eissing]

  *) COMPATIBILITY: mod_proxy_fcgi: Revert to 2.4.20 FCGI behavior for the
     default ProxyFCGIBackendType, fixing a regression with PHP-FPM. PR 61202.
     [Jacob Champion, Jim Jagielski]

  *) mod_lua: Improve compatibility with Lua 5.1, 5.2 and 5.3.
     PR58188, PR60831, PR61245. [Rainer Jung]

  *) mod_http2: Simplify ready queue, less memory and better performance. Update
     mod_http2 version to 1.10.7. [Stefan Eissing]

  *) Allow single-char field names inadvertently disallowed in 2.4.25.
     PR 61220. [Yann Ylavic]

  *) htpasswd / htdigest: Do not apply the strict permissions of the temporary
     passwd file to a possibly existing passwd file. PR 61240. [Ruediger Pluem]

  *) core: Avoid duplicate HEAD in Allow header.
     This is a regression in 2.4.24 (unreleased), 2.4.25 and 2.4.26.
     PR 61207. [Christophe Jaillet]

Changes with Apache 2.4.26

  *) SECURITY: CVE-2017-7679 (cve.mitre.org)
     mod_mime can read one byte past the end of a buffer when sending a
     malicious Content-Type response header.  [Yann Ylavic]

  *) SECURITY: CVE-2017-7668 (cve.mitre.org)
     The HTTP strict parsing changes added in 2.2.32 and 2.4.24 introduced a
     bug in token list parsing, which allows ap_find_token() to search past
     the end of its input string. By maliciously crafting a sequence of
     request headers, an attacker may be able to cause a segmentation fault,
     or to force ap_find_token() to return an incorrect value.
     [Jacob Champion]

  *) SECURITY: CVE-2017-7659 (cve.mitre.org)
     A maliciously constructed HTTP/2 request could cause mod_http2 to
     dereference a NULL pointer and crash the server process.

  *) SECURITY: CVE-2017-3169 (cve.mitre.org)
     mod_ssl may dereference a NULL pointer when third-party modules call
     ap_hook_process_connection() during an HTTP request to an HTTPS port.
     [Yann Ylavic]

  *) SECURITY: CVE-2017-3167 (cve.mitre.org)
     Use of the ap_get_basic_auth_pw() by third-party modules outside of the
     authentication phase may lead to authentication requirements being
     bypassed.
     [Emmanuel Dreyfus <manu netbsd.org>, Jacob Champion, Eric Covener]

  *) HTTP/2 support no longer tagged as "experimental" but is instead considered
     fully production ready.

  *) mod_http2: Fix for possible CPU busy loop introduced in v1.10.3 where a stream may keep
     the session in continuous check for state changes that never happen.
     [Stefan Eissing]

  *) mod_proxy_wstunnel: Add "upgrade" parameter to allow upgrade to other
     protocols.  [Jean-Frederic Clere]

  *) MPMs unix: Place signals handlers and helpers out of DSOs to avoid
     a possible crash if a signal is caught during (graceful) restart.
     PR 60487.  [Yann Ylavic]

  *) mod_rewrite: When a substitution is a fully qualified URL, and the
     scheme/host/port matches the current virtual host, stop interpreting the
     path component as a local path just because the first component of the
     path exists in the filesystem.  Adds RewriteOption "LegacyPrefixDocRoot"
     to revert to previous behavior. PR60009.
     [Hank Ibell <hwibell gmail.com>]

  *) core: ap_parse_form_data() URL-decoding doesn't work on EBCDIC
     platforms. PR61124. [Hank Ibell <hwibell gmail.com>]

  *) ab: enable option processing for setting a custom HTTP method also for
     non-SSL builds.  [Rainer Jung]

  *) core: EBCDIC fixes for interim responses with additional headers.
     [Eric Covener]

  *) mod_env: when processing a 'SetEnv' directive, warn if the environment
     variable name includes a '='. It is likely a configuration error.
     PR 60249 [Christophe Jaillet]

  *) Evaluate nested If/ElseIf/Else configuration blocks.
     [Luca Toscano, Jacob Champion]

  *) mod_rewrite: Add 'BNP' (backreferences-no-plus) flag to RewriteRule to
     allow spaces in backreferences to be encoded as %20 instead of '+'.
     [Eric Covener]

  *) mod_rewrite: Add the possibility to limit the escaping to specific
     characters in backreferences by listing them in the B flag.
     [Eric Covener]

  *) mod_substitute: Fix spurious AH01328 (Line too long) errors on EBCDIC
     systems.  [Eric Covener]

  *) mod_http2: fail requests without ERROR log in case we need to read interim
     responses and see only garbage. This can happen if proxied servers send
     data where none should be, e.g. a body for a HEAD request. [Stefan Eissing]

  *) mod_proxy_http2: adding support for Reverse Proxy Request headers.
     [Stefan Eissing]

  *) mod_http2: fixed possible deadlock that could occur when connections were
     terminated early with ongoing streams. Fixed possible hanger with timeout
     on race when connection considers itself idle. [Stefan Eissing]

  *) mod_http2: MaxKeepAliveRequests now limits the number of times a
     slave connection gets reused. [Stefan Eissing]

  *) mod_brotli: Add a new module for dynamic Brotli (RFC 7932) compression.
     [Evgeny Kotkov]

  *) mod_proxy_http2: Fixed bug in re-attempting proxy requests after
     connection error. Reliability of reconnect handling improved.
     [Stefan Eissing]

  *) mod_http2: better performance, eliminated need for nested locks and
     thread privates. Moving request setups from the main connection to the
     worker threads. Increase number of spare connections kept.
     [Stefan Eissing]

  *) mod_http2: input buffering and dynamic flow windows for increased
     throughput. Requires nghttp2 >= v1.5.0 features. Announced at startup
     in mod_http2 INFO log as feature 'DWINS'. [Stefan Eissing]

  *) mod_http2: h2 workers with improved scalability for better scheduling
     performance. There are H2MaxWorkers threads created at start and the
     number is kept constant for now. [Stefan Eissing]

  *) mod_http2: obsoleted option H2SessionExtraFiles, will be ignored and
     just log a warning. [Stefan Eissing]

  *) mod_autoindex: Add IndexOptions UseOldDateFormat to allow the date
     format from 2.2 in the Last Modified column. PR60846.
     [Hank Ibell <hwibell gmail.com>]

  *) core: Add %{REMOTE_PORT} to the expression parser. PR59938
     [Hank Ibell <hwibell gmail.com>]

  *) mod_cache: Fix a regression in 2.4.25 for the forward proxy case by
     computing and using the same entity key according to when the cache
     checks, loads and saves the request.
     PR 60577.  [Yann Ylavic]

  *) mod_proxy_hcheck: Don't validate timed out responses.  [Yann Ylavic]

  *) mod_proxy_hcheck: Ensure thread-safety when concurrent healthchecks are
     in use (ProxyHCTPsize > 0).  PR 60071.  [Yann Ylavic, Jim Jagielski]

  *) core: %{DOCUMENT_URI} used in nested SSI expressions should point to the
     URI originally requested by the user, not the nested documents URI. This
     restores the behavior of this variable to match the "legacy" SSI parser.
     PR60624. [Hank Ibell <hwibell gmail.com>]

  *) mod_proxy_fcgi: Add ProxyFCGISetEnvIf to fixup CGI environment
     variables just before invoking the FastCGI. [Eric Covener,
     Jacob Champion]

  *) mod_proxy_fcgi: Return to 2.4.20-and-earlier behavior of leaving
     a "proxy:fcgi://" prefix in the SCRIPT_FILENAME environment variable by
     default.  Add ProxyFCGIBackendType to allow the type of backend to be
     specified so these kinds of fixups can be restored without impacting
     FPM. PR60576 [Eric Covener, Jim Jagielski]

  *) mod_ssl: work around leaks on (graceful) restart. [Yann Ylavic]

  *) mod_ssl: Add support for OpenSSL 1.1.0. [Rainer Jung]

  *) Don't set SO_REUSEPORT unless ListenCoresBucketsRatio is greater
     than zero.  [Eric Covener]

  *) mod_http2: moving session cleanup to pre_close hook to avoid races with
     modules already shut down and slave connections still operating.
     [Stefan Eissing]

  *) mod_lua: Support for Lua 5.3

  *) mod_proxy_http2: support for ProxyPreserverHost directive. [Stefan Eissing]

  *) mod_http2: fix for crash when running out of memory.
     [Robert Swiecki <robert swiecki.net>, Stefan Eissing]

  *) mod_proxy_fcgi: Return HTTP 504 rather than 503 in case of proxy timeout.
     [Luca Toscano]

  *) mod_http2: not counting file buckets again stream max buffer limits.
     Effectively transferring static files in one step from slave to master
     connection. [Stefan Eissing]

  *) mod_http2: comforting ap_check_pipeline() on slave connections
     to facilitate reuse (see https://github.com/icing/mod_h2/issues/128).
     [Stefan Eissing, reported by Armin Abfalterer]

  *) mod_http2: http/2 streams now with state handling/transitions as defined
     in RFC7540. Stream cleanup/connection shutdown reworked to become easier
     to understand/maintain/debug. Added many asserts on state and cleanup
     transitions. [Stefan Eissing]

  *) mod_auth_digest: Use an anonymous shared memory segment by default,
     preventing startup failure after unclean shutdown.  PR 54622.
     [Jan Kaluza]

  *) mod_filter: Fix AddOutputFilterByType with non-content-level filters.
     PR 58856. [Micha Lenk <micha lenk.info>]

  *) mod_watchdog: Fix semaphore leak over restarts.  [Jim Jagielski]

  *) mod_http2: regression fix on PR 59348, on graceful restart, ongoing
     streams are finished normally before the final GOAWAY is sent.
     [Stefan Eissing, <slavko gmail.com>]

  *) mod_proxy: Allow the per-request environment variable "no-proxy" to
     be used as an alternative to ProxyPass /path !. This is primarily
     to set exceptions for ProxyPass specified in <Location> context.
     Use SetEnvIf, not SetEnv. PR 60458.  [Eric Covener]

  *) mod_http2: fixes PR60599, sending proper response for conditional requests
     answered by mod_cache. [Jeff Wheelhouse, Stefan Eissing]

  *) mod_http2: rework of stream resource cleanup to avoid a crash in a close
     of a lingering connection. Prohibit special file bucket beaming for
     shared buckets. Files sent in stream output now use the stream pool
     as read buffer, reducing memory footprint of connections.
     [Yann Ylavic, Stefan Eissing]

  *) mod_proxy_fcgi, mod_fcgid: Fix crashes in ap_fcgi_encoded_env_len() when
     modules add empty environment variables to the request. PR 60275.
     [<alex2grad AT gmail.com>]

  *) mod_http2: fix for possible page fault when stream is resumed during
     session shutdown. [sidney-j-r-m (github)]

  *) mod_http2: fix for h2 session ignoring new responses while already
     open streams continue to have data available. [Stefan Eissing]

  *) mod_http2: adding support for MergeTrailers directive. [Stefan Eissing]

  *) mod_http2: limiting DATA frame sizes by TLS record sizes in use on the
     connection. Flushing outgoing frames earlier. [Stefan Eissing]

  *) mod_http2: cleanup beamer registry on server reload.  PR 60510.
     [Pavel Mateja <pavel verotel.cz>, Stefan Eissing]

  *) mod_proxy_{ajp,fcgi}: Fix a possible crash when reusing an established
     backend connection, happening with LogLevel trace2 or higher configured,
     or at any log level with compilers not detected as C99 compliant (e.g.
     MSVC on Windows).  [Yann Ylavic]

  *) mod_ext_filter: Don't interfere with "error buckets" issued by other
     modules. PR 60375.  [Eric Covener, Lubos Uhliarik]

  *) mod_http2: fixes https://github.com/icing/mod_h2/issues/126 e.g. beam
     bucket lifetime handling when data is sent over temporary pools.
     [Stefan Eissing]

Changes with Apache 2.4.25

  *) Fix some build issues related to various modules.
     [Rainer Jung]

Changes with Apache 2.4.24 (not released)

  *) SECURITY: CVE-2016-8740 (cve.mitre.org)
     mod_http2: Mitigate DoS memory exhaustion via endless
     CONTINUATION frames.
     [Naveen Tiwari <naveen.tiwari@asu.edu> and CDF/SEFCOM at Arizona State
     University, Stefan Eissing]

  *) SECURITY: CVE-2016-2161 (cve.mitre.org)
     mod_auth_digest: Prevent segfaults during client entry allocation when
     the shared memory space is exhausted.
     [Maksim Malyutin <m.malyutin dsec.ru>, Eric Covener, Jacob Champion]

  *) SECURITY: CVE-2016-0736 (cve.mitre.org)
     mod_session_crypto: Authenticate the session data/cookie with a
     MAC (SipHash) to prevent deciphering or tampering with a padding
     oracle attack.  [Yann Ylavic, Colm MacCarthaigh]

  *) SECURITY: CVE-2016-8743 (cve.mitre.org)
     Enforce HTTP request grammar corresponding to RFC7230 for request lines
     and request headers, to prevent response splitting and cache pollution by
     malicious clients or downstream proxies. [William Rowe, Stefan Fritsch]

  *) Validate HTTP response header grammar defined by RFC7230, resulting
     in a 500 error in the event that invalid response header contents are
     detected when serving the response, to avoid response splitting and cache
     pollution by malicious clients, upstream servers or faulty modules.
     [Stefan Fritsch, Eric Covener, Yann Ylavic]

  *) core: Mitigate [f]cgi CVE-2016-5387 "httpoxy" issues.
     [Dominic Scheirlinck <dominic vendhq.com>, Yann Ylavic]

  *) mod_rewrite: Limit runaway memory use by short circuiting some kinds of
     looping RewriteRules when the local path significantly exceeds
     LimitRequestLine.  PR 60478. [Jeff Wheelhouse <apache wheelhouse.org>]

  *) mod_ratelimit: Allow for initial "burst" amount at full speed before
     throttling: PR 60145 [Andy Valencia <ajv-etradanalhos vsta.org>,
     Jim Jagielski]

  *) mod_socache_memcache: Provide memcache stats to mod_status.
     [Jim Jagielski]

  *) mod_file_cache: mod_file_cache should be able to serve files that
     haven't had a Content-Type set via e.g. mod_mime. [Eric Covener]

  *) http_filters: Fix potential looping in new check_headers() due to new
     pattern of ap_die() from http header filter. Explicitly clear the
     previous headers and body.

  *) core: Drop Content-Length header and message-body from HTTP 204 responses.
     PR 51350 [Luca Toscano]

  *) mod_proxy: Honor a server scoped ProxyPass exception when ProxyPass is
     configured in <Location>, like in 2.2. PR 60458.
     [Eric Covener]

  *) mod_lua: Fix default value of LuaInherit directive. It should be
     'parent-first' instead of 'none', as per documentation.  PR 60419
     [Christophe Jaillet]

  *) core: New directive HttpProtocolOptions to control httpd enforcement
     of various RFC7230 requirements. [Stefan Fritsch, William Rowe]

  *) core: Permit unencoded ';' characters to appear in proxy requests and
     Location: response headers. Corresponds to modern browser behavior.
     [William Rowe]

  *) core: ap_rgetline_core now pulls from r->proto_input_filters.

  *) core: Correctly parse an IPv6 literal host specification in an absolute
     URL in the request line. [Stefan Fritsch]

  *) core: New directive RegisterHttpMethod for registering non-standard
     HTTP methods. [Stefan Fritsch]

  *) mod_socache_memcache: Pass expiration time through to memcached. PR 55445.
     [Faidon Liambotis <paravoid debian.org>, Joe Orton]

  *) mod_cache: Use the actual URI path and query-string for identifying the
     cached entity (key), such that rewrites are taken into account when
     running afterwards (CacheQuickHandler off).  PR 21935.  [Yann Ylavic]

  *) mod_http2: new directive 'H2EarlyHints' to enable sending of HTTP status
     103 interim responses. Disabled by default. [Stefan Eissing]

  *) mod_ssl: Fix quick renegotiation (OptRenegotiaton) with no intermediate
     in the client certificate chain.  PR 55786.  [Yann Ylavic]

  *) event: Allow to use the whole allocated scoreboard (up to ServerLimit
     slots) to avoid scoreboard full errors when some processes are finishing
     gracefully. Also, make gracefully finishing processes close all
     keep-alive connections. PR 53555. [Stefan Fritsch]

  *) mpm_event: Don't take over scoreboard slots from gracefully finishing
     threads. [Stefan Fritsch]

  *) mpm_event: Free memory earlier when shutting down processes.
     [Stefan Fritsch]

  *) mod_status: Display the process slot number in the async connection
     overview. [Stefan Fritsch]

  *) mod_dir: Responses that go through "FallbackResource" might appear to
     hang due to unterminated chunked encoding. PR58292. [Eric Covener]

  *) mod_dav: Fix a potential cause of unbounded memory usage or incorrect
     behavior in a routine that sends <DAV:response>'s to the output filters.
     [Evgeny Kotkov]

  *) mod_http2: new directive 'H2PushResource' to enable early pushes before
     processing of the main request starts. Resources are announced to the
     client in Link headers on a 103 early hint response.
     All responses with status code <400 are inspected for Link header and
     trigger pushes accordingly. 304 still does prevent pushes.
     'H2PushResource' can mark resources as 'critical' which gives them higher
     priority than the main resource. This leads to preferred scheduling for
     processing and, when content is available, will send it first. 'critical'
     is also recognized on Link headers. [Stefan Eissing]

  *) mod_proxy_http2: uris in Link headers are now mapped back to a suitable
     local url when available. Relative uris with an absolute path are mapped
     as well. This makes reverse proxy mapping available for resources
     announced in this header.
     With 103 interim responses being forwarded to the main client connection,
     this effectively allows early pushing of resources by a reverse proxied
     backend server. [Stefan Eissing]

  *) mod_proxy_http2: adding support for newly proposed 103 status code.
     [Stefan Eissing]

  *) mpm_unix: Apache fails to start if previously crashed then restarted with
     the same PID (e.g. in container).  PR 60261.
     [Val <valentin.bremond gmail.com>, Yann Ylavic]

  *) mod_http2: unannounced and multiple interim responses (status code < 200)
     are parsed and forwarded to client until a final response arrives.
     [Stefan Eissing]

  *) mod_proxy_http2: improved robustness when main connection is closed early
     by resetting all ongoing streams against the backend.
     [Stefan Eissing]

  *) mod_http2: allocators from slave connections are released earlier,
     resulting in less overall memory use on busy, long lived connections.
     [Stefan Eissing]

  *) mod_remoteip: Pick up where we left off during a subrequest rather
     than running with the modified XFF but original TCP address.
     PR 49839/PR 60251

  *) http: Respond with "408 Request Timeout" when a timeout occurs while
     reading the request body.  [Yann Ylavic]

  *) mod_http2: connection shutdown revisited: corrected edge cases on
     shutting down ongoing streams, changed log warnings to be less noisy
     when waiting on long running tasks. [Stefan Eissing]

  *) mod_http2: changed all AP_DEBUG_ASSERT to ap_assert to have them
     available also in normal deployments. [Stefan Eissing]

  *) mod_http2/mod_proxy_http2: 100-continue handling now properly implemented
     up to the backend. Reused HTTP/2 proxy connections with more than a second
     not used will block request bodies until a PING answer is received.
     Requests headers are not delayed by this, since they are repeatable in
     case of failure. This greatly increases robustness, especially with
     busy server and/or low keepalive connections. [Stefan Eissing]

  *) mod_proxy_http2: fixed duplicate symbols with mod_http2.
     [Stefan Eissing]

  *) mod_http2: rewrite of how responses and trailers are transferred between
     master and slave connection. Reduction of internal states for tasks
     and streams, stability. Heuristic id generation for slave connections
     to better keep promise of connection ids unique at given point int time.
     Fix for mod_cgid interop in high load situations.
     Fix for handling of incoming trailers when no request body is sent.
     [Stefan Eissing]

  *) mod_http2: fix suspended handling for streams. Output could become
     blocked in rare cases. [Stefan Eissing]

  *) mpm_winnt: Prevent a denial of service when the 'data' AcceptFilter is in
     use by replacing it with the 'connect' filter. PR 59970. [Jacob Champion]

  *) mod_cgid: Resolve a case where a short CGI response causes a subsequent
     CGI to be killed prematurely, resulting in a truncated subsequent
     response. [Eric Covener]

  *) mod_proxy_hcheck: Set health check URI and expression correctly for health
     check worker. PR 60038 [zdeno <zdeno@scnet.sk>]

  *) mod_http2: if configured with nghttp2 1.14.0 and onward, invalid request
     headers will immediately reset the stream with a PROTOCOL error. Feature
     logged by module on startup as 'INVHD' in info message.
     [Stefan Eissing]

  *) mod_http2: fixed handling of stream buffers during shutdown.
     [Stefan Eissing]

  *) mod_reqtimeout: Fix body timeout disabling for CONNECT requests to avoid
     triggering mod_proxy_connect's AH01018 once the tunnel is established.
     [Yann Ylavic]

  *) ab: Set the Server Name Indication (SNI) extension on outgoing TLS
     connections (unless -I is specified), according to the Host header (if
     any) or the requested URL's hostname otherwise.  [Yann Ylavic]

  *) mod_proxy_fcgi: avoid loops when ProxyErrorOverride is enabled
     and the error documents are proxied. PR 55415. [Luca Toscano]

  *) mod_proxy_fcgi: read the whole FCGI response even when the content
     has not been modified (HTTP 304) or in case of a precondition failure
     (HTTP 412) to avoid subsequent bogus reads and confusing
     error messages logged. [Luca Toscano]

  *) mod_http2: h2 status resource follows latest draft, see
     http://www.ietf.org/id/draft-benfield-http2-debug-state-01.txt
     [Stefan Eissing]

  *) mod_http2: handling graceful shutdown gracefully, e.g. handling existing
     streams to the end. [Stefan Eissing]

  *) mod_proxy_{http,ajp,fcgi}: don't reuse backend connections with data
     available before the request is sent.  PR 57832.  [Yann Ylavic]

  *) mod_proxy_balancer: Prevent redirect loops between workers within a
     balancer by limiting the number of redirects to the number balancer
     members. PR 59864 [Ruediger Pluem]

  *) mod_proxy: Correctly consider error response codes by the backend when
     processing failonstatus. PR 59869 [Ruediger Pluem]

  *) mod_dav: Add dav_get_provider_name() function to obtain the name
     of the provider from mod_dav.  [Graham Leggett]

  *) mod_dav: Add support for childtags to dav_error.
     [Jari Urpalainen <jari.urpalainen nokia.com>]

  *) mod_proxy_fcgi: Fix 2.4.23 breakage for mod_rewrite per-dir and query
     string showing up in SCRIPT_FILENAME. PR59815

  *) mod_include: Fix a potential memory misuse while evaluating expressions.
     PR59844. [Eric Covener]

  *) mod_http2: new H2CopyFiles directive that changes treatment of file
     handles in responses. Necessary in order to fix broken lifetime handling
     in modules such as mod_wsgi.

  *) mod_http2: removing timeouts on master connection while requests are
     being processed. Requests may timeout, but the master only times out when
     no more requests are active. [Stefan Eissing]

  *) mod_http2: fixes connection flush when answering SETTINGS without any
     stream open. [Moto Ishizawa <@summerwind>, Stefan Eissing]

Changes with Apache 2.4.23

  *) mod_ssl: reset client-verify state of ssl when aborting renegotiations.
     [Erki Aring <erki@example.ee>, Stefan Eissing]

  *) mod_sed: Fix 'x' command processing. [Christophe Jaillet]

  *) configure: Fix ./configure edge-case failures around dependencies
     of mod_proxy_hcheck. [William Rowe, Ruediger Pluem, Jeff Trawick]

Changes with Apache 2.4.22

  *) mod_http2: fix for request abort when connections drops, introduced in
     1.5.8

Changes with Apache 2.4.21

  *) core: Added support for HTTP code 451. PR 58985.
     [Yehuda Katz <yehuda ymkatz.net>, Jim Jagielski]

  *) ab: Use caseless matching for HTTP tokens (e.g. content-length). PR 59111.
     [Yann Ylavic]

  *) mod_http2: more rigid error handling in DATA frame assembly, leading
     to deterministic connection errors if assembly fails.
     [Stefan Eissing, Pal Nilsen <https://github.com/maedox>]

  *) abs: Include OPENSSL_Applink when compiling on Windows, to resolve
     failures under Visual Studio 2015 and other mismatched MSVCRT flavors.
     PR59630 [Jan Ehrhardt <phpdev ehrhardt.nl>]

  *) mod_ssl: Add "no_crl_for_cert_ok" flag to SSLCARevocationCheck directive
     to opt-in previous behaviour (2.2) with CRLs verification when checking
     certificate(s) with no corresponding CRL.  [Yann Ylavic]

  *) mpm_event, mpm_worker: Fix computation of MinSpareThreads' lower bound
     according the number of listeners buckets.  [Yann Ylavic]

  *) Add ap_cstr_casecmp[n]() - placeholder of apr_cstr_casecmp[n] functions
     for case-insensitive C/POSIX-locale token comparison.
     [Jim Jagielski, William Rowe, Yann Ylavic, Branko Čibej]

  *) mod_userdir: Constify and save a few bytes in the conf pool when
     parsing the "UserDir" directive. [Christophe Jaillet]

  *) mod_cache: Fix (max-stale with no '=') and enforce (check
     integers after '=') Cache-Control header parsing.
     [Christophe Jaillet]

  *) core: Add -DDUMP_INCLUDES configtest option to show the tree
     of Included configuration files.
     [Jacob Champion <champion.pxi gmail.com>]

  *) mod_proxy_fcgi: Avoid passing a filename of proxy:fcgi:// as
     SCRIPT_FILENAME to a FastCGI server. PR59618.
     [Jacob Champion <champion.pxi gmail.com>]

  *) mod_dav: Add dav_get_provider_name() function to obtain the name
     of the provider from mod_dav.
     [Jari Urpalainen <jari.urpalainen nokia.com>]

  *) mod_proxy_http2: properly care for HTTP2 flow control of the frontend
     connection is HTTP/1.1. [Patch supplied by Evgeny Kotkov]

  *) mod_http2: improved cleanup of connection/streams/tasks to always
     have deterministic order regardless of event initiating it. Addresses
     reported crashes due to memory read after free issues.
     [Stefan Eissing]

  *) mod_ssl: Correct the interaction between SSLProxyCheckPeerCN and newer
     SSLProxyCheckPeerName directives since release 2.4.5, such that disabling
     either disables both, and that enabling either triggers the new, more
     comprehensive SSLProxyCheckPeerName behavior. Only a single configuration
     remains to enable the legacy behavior, which is to explicitly disable
     SSLProxyCheckPeerName, and enable SSLProxyCheckPeerCN. [William Rowe]

  *) mod_include: add the <!--#comment ...> syntax in order to include comments
     in a SSI file. [Christophe Jaillet based on a suggestion from Rob]

  *) mod_http2: improved event handling for suspended streams, responses
     and window updates. [Stefan Eissing]

  *) mod_proxy_hcheck: Provide for dynamic background health
     checks on reverse proxies associated with BalancerMember
     workers. [Jim Jagielski]

  *) mod_http2: Fix async write issue that led to selection of wrong timeout
     vs. keepalive timeout selection for idle sessions. [Stefan Eissing]

  *) mod_http2: checking LimitRequestLine, LimitRequestFields and
     LimitRequestFieldSize configurated values for incoming streams. Returning
     HTTP status 431 for too long/many headers fields and 414 for a too long
     pseudo header. [Stefan Eissing]

  *) mod_http2: tracking conn_rec->current_thread on slave connections, so
     that mod_lua finds the correct one. Fixes PR 59542. [Stefan Eissing]

  *) mod_proxy_http2: new experimental http2 proxy module for h2: and h2c: proxy
     urls. Part of the httpd mod_proxy framework, common settings apply.
     Requests from the same HTTP/2 frontend connection against the same backend
     are aggregated on a single connection.
     [Stefan Eissing]

  *) mod_http2: slave connections have conn_rec->aborted flag set when a stream
     has been reset by the client. [Stefan Eissing]

  *) mod_http2: merge of some 2.4.x adaptions re filters on slave connections.
     Small fixes in bucket beams when forwarding file buckets. Output handling
     on master connection uses less FLUSH and passes automatically when more
     than half of H2StreamMaxMemSize bytes have accumulated.
     Workaround for http: when forwarding partial file buckets to keep the
     output filter from closing these too early. [Stefan Eissing]

  *) mod_http2: elimination of fixed master connection buffer for TLS
     connections. New scratch bucket handling optimized for TLS write sizes.
     File bucket data read directly into scratch buffers, avoiding one
     copy. Non-TLS connections continue to pass buckets unchanged to the core
     filters to allow sendfile() usage. [Stefan Eissing]

  *) mod_http2/mod_proxy_http2: h2_request.c is no longer shared between these
     modules. This simplifies building on platforms such as Windows, as module
     reference used in logging is now clear. [Stefan Eissing]

  *) Scoreboard: Fix a regression in 2.4.20 that causes wrong request data
     to be displayed on the status page. PR 59333. [Yann Ylavic, William Rowe]

  *) mod_http2: fixed a bug that caused mod_proxy_http2 to be called for window
     updates on requests it had already reported done. Added synchronization
     on early connection/stream close that lets ongoing requests safely drain
     their input filters.
     [Stefan Eissing]

  *) mod_http2: scoreboard updates that summarize the h2 session (and replace
     the last request information) will only happen when the session is idle or
     in shutdown/done phase. [Stefan Eissing]

  *) mod_http2: new "bucket beam" technology to transport buckets across
     threads without buffer copy. Delaying response start until flush or
     enough body data has been accumulated. Overall significantly smaller
     memory footprint. [Stefan Eissing]

  *) core: New CGIVar directive can configure REQUEST_URI to represent the
     current URI being processed instead of always the original request.
     [Jeff Trawick]

  *) scoreboard/status: Restore behavior of showing workers' previous Client,
     VHost and Request values when idle, like in 2.4.18 and earlier.

  *) mod_http2: r->protocol changed to "HTTP/2.0" (was "HTTP/2") as this will
     give expected syntax in CGI's SERVER_PROTOCOL is more compatible with
     existing major/minor handling. Fixes PR 59313.

  *) mod_http2: disabling mmap for file buckets transport due to segmenation
     faults when files change on the fly.

Changes with Apache 2.4.20

  *) SECURITY: CVE-2016-1546 (cve.mitre.org)
     mod_http2: restricting number of concurrent stream workers per connection
     if client is slow.

  *) core: Do not read .htaccess if AllowOverride and AllowOverrideList
     are "None". PR 58528.
     [Michael Schlenker <msc contact.de, Ruediger Pluem, Daniel Ruggeri]

  *) mod_proxy_express: Fix possible use of DB handle after close.  PR 59230.
     [Petr <pgajdos suse.cz>]

  *) core/util_script: relax alphanumeric filter of environment variable names
     on Windows to allow '(' and ')' for passing PROGRAMFILES(X86) et.al.
     unadulterated in 64 bit versions of Windows. PR 46751.
     [John <john leineweb de>]

  *) mod_http2: incrementing keepalives on each request started so that logging
     %k gives increasing numbers per master http2 connection.
     New documented variables in env, usable in custom log formats: H2_PUSH,
     H2_PUSHED, H2_PUSHED_ON, H2_STREAM_ID and H2_STREAM_TAG.
     [Stefan Eissing]

  *) mod_http2: more efficient passing of response bodies with less contention
     and file bucket forwarding. [Stefan Eissing]

  *) mod_http2: fix for missing score board updates on request count, fix for
     memory leak on slave connection reuse. [Stefan Eissing]

  *) mod_http2: Fix build on Windows from dsp files.
     [Stefan Eissing]

Changes with Apache 2.4.19

  *) mod_ssl: Add missing Upgrade/Connection headers in case of TRACE or
     OPTIONS * requests. PR 58688. [William Rowe]

  *) mod_include: Add variable DOCUMENT_ARGS, with the arguments to the
     request for the SSI document.  [Jeff Trawick]

  *) mod_authz_host: Add a new "forward-dns" authorization type, not relying on
     reverse DNS lookups.  [Fabien]

  *) mod_proxy_http2: new experimental http2 proxy module for h2: and h2c: proxy
     urls. Uses backend connections for concurrent requests if frontend
     connection is http2 as well.
     [Stefan Eissing]

  *) mod_ssl: Add hooks to allow other modules to perform processing at
     several stages of initialization and connection handling.  See
     mod_ssl_openssl.h.  [Jeff Trawick]

  *) mod_http2: disabling PUSH when client sends GOAWAY. Slave connections are
     reused for several requests, improved performance and better memory use.
     [Stefan Eissing]

  *) mod_rewrite: Don't implicitly URL-escape the original query string
     when no substitution has changed it (like PR50447 but server context)
     [Evgeny Kotkov <evgeny.kotkov visualsvn.com>]

  *) mod_http2: fixes problem with wrong lifetime of file buckets on main
     connection. [Stefan Eissing]

  *) mod_http2: fixes incorrect denial of requests without :authority header.
     [Stefan Eissing]

  *) mod_reqtimeout: Prevent long response times from triggering a timeout once
     the request has been fully read.  PR 59045.  [Yann Ylavic]

  *) ap_expr: expression support for variable HTTP2=on|off. [Stefan Eissing]

  *) mod_http2: give control to async mpm for keepalive timeouts only when
     no streams are open and even if only after 1 sec delay. Under load, event
     mpm discards connections otherwise too quickly. [Stefan Eissing]

  *) mod_ssl: Don't lose track of the SSL context if an unlikely failure occurs
     in ssl_init_ssl_connection().  [Graham Leggett]

  *) mod_rewrite: Add QSL|qslast flag to allow rewrites to files with
     literal question marks in their names. PR 58777. [Eric Covener]

  *) event: use pre_connection hook to properly initialize connection state for
     slave connections. use protocol_switch hook to initialize server config
     early based on SNI selected vhost.
     [Stefan Eissing]

  *) hostname: Test and log useragent_host per-request across various modules,
     including the scoreboard, expression and rewrite engines, setenvif,
     authz_host, access_compat, custom logging, ssl and REMOTE_HOST variables.
     PR55348  [William Rowe]

  *) core: Track the useragent_host per-request when mod_remoteip or similar
     modules track a per-request useragent_ip.  Modules should be updated
     to inquire for ap_get_useragent_host() in place of ap_get_remote_host().
     [William Rowe]

  *) core: fix a bug in <UnDefine ...> directive processing. When used, the last
     <Define...>'ed variable was also withdrawn. PR 59019
     [Christophe Jaillet]

  *) mod_http2: Accept-Encoding is, when present on the initiating request,
     added to push promises. This lets compressed content work in pushes.
     by the client. [Stefan Eissing]

  *) mod_http2: fixed possible read after free when streams were cancelled early
     by the client. [Stefan Eissing]

  *) mod_http2: fixed possible deadlock during connection shutdown. Thanks to
     @FrankStolle for reporting and getting the necessary data.
     [Stefan Eissing]

  *) mod_http2: fixed apr_uint64_t formatting in a log statement to user proper
     APR def, thanks to @Sp1l.

  *) mod_http2: number of worker threads allowed to a connection is adjusting
     dynamically. Starting with 4, the number is doubled when streams can be
     served without block on http/2 connection flow. The number is halfed, when
     the server has to wait on client flow control grants.
     This can happen with a maximum frequency of 5 times per second.
     When a connection occupies too many workers, repeatable requests
     (GET/HEAD/OPTIONS) are cancelled and placed back in the queue. Should that
     not suffice and a stream is busy longer than the server timeout, the
     connection will be aborted with error code ENHANCE_YOUR_CALM.
     This does *not* limit the number of streams a client may open, rather the
     number of server threads a connection might use.
     [Stefan Eissing]

  *) mod_http2: allowing link header to specify multiple "rel" values,
     space-separated inside a quoted string. Prohibiting push when Link
     parameter "nopush" is present.
     [Stefan Eissing]

  *) mod_http2: reworked connection state handling. Idle connections accept a
     GOAWAY from the client without further reply. Otherwise the
     module makes a best effort to send one last GOAWAY to the client.

  *) mod_http2: the values from standard directives Timeout and KeepAliveTimeout
     properly are applied to http/2 connections.
     [Stefan Eissing]

  *) mod_http2: idle connections are returned to async mpms. new hook
     "pre_close_connection" used to send GOAWAY frame when not already done.
     Setting event mpm server config "by hand" for the main connection to
     the correct negotiated server.
     [Stefan Eissing]

  *) mod_http2: keep-alive blocking reads are done with 1 second timeouts to
     check for MPM stopping. Will announce early GOAWAY and finish processing
     open streams, then close.
     [Stefan Eissing]

  *) mod_http2: bytes read/written on slave connections are reported via the
     optional mod_logio functions. Fixes PR 58871.

  *) prefork: Initialize the POD when running in ONE_PROCESS (or -X) mode to
     avoid a crash.  [Jan Kaluza, Yann Ylavic]

  *) mod_ssl: When SSLVerify is disabled (NONE), don't force a renegotiation if
     the SSLVerifyDepth applied with the default/handshaken vhost differs from
     the one applicable with the finally selected vhost.  [Yann Ylavic]

  *) core: Ensure that httpd exits with an error status when the MPM fails
     to run.  [Yann Ylavic]

  *) mod_ssl: Fix a possible memory leak on restart for custom [EC]DH params.
     [Jan Kaluza, Yann Ylavic]

  *) mod_ssl: Add SSLOCSPProxyURL to add the possibility to do all queries
     to OCSP responders through a HTTP proxy. [Ruediger Pluem]

  *) mod_proxy: Play/restore the TLS-SNI on new backend connections which
     had to be issued because the remote closed the previous/reusable one
     during idle (keep-alive) time.  [Yann Ylavic]

  *) mod_cache_socache: Fix a possible cached entity body corruption when it
     is received from an origin server in multiple batches and forwarded by
     mod_proxy.  [Yann Ylavic]

  *) core: Add expression support to SetHandler.
     [Eric Covener]

  *) mod_remoteip: Prevent an external proxy from presenting an internal
     proxy. PR 55962. [Mike Rumph]

  *) core: Prevent a server crash in case of an invalid CONNECT request with
     a custom error page for status code 400 that uses server side includes.
     PR 58929 [Ruediger Pluem]

  *) mod_ssl: handle TIMEOUT on empty SSL input as non-fatal, returning
     APR_TIMEUP and preserving connection state for later retry.
     [Stefan Eissing]

  *) mod_ssl: Save some TLS record (application data) fragmentations by
     including the last and subsequent suitable buckets when coalescing.
     [Yann Ylavic]

  *) mod_proxy_fcgi: Suppress HTTP error 503 and message 01075,
     "Error dispatching request", when the cause appears to be
     due to the client closing the connection.
     PR58118.  [Tobias Adolph <adolph lrz.de>]

  *) mod_cgid: Message AH02550, failure to flush a response to the client,
     is now logged at TRACE1 level to match the underlying core output filter
     severity.  [Eric Covener]

  *) mime.types: add common extension "m4a" for MPEG 4 Audio.
     PR 57895 [Dylan Millikin <dylan.millikin gmail.com>]

  *) Added many log numbers to log statements that had none.
     [Rainer Jung]

  *) mod_log_config: Add GlobalLog to allow a globally defined log to
     be inherited by virtual hosts that define a CustomLog.
     [Edward Lu]

  *) mod_http2: connections how keep a "push diary" where hashes of already
     pushed resources are kept. See directive H2PushDiarySize for managing this.
     Push diaries can be initialized by clients via the "Cache-Digest" request
     header. This carries a base64url encoded. compressed Golomb set as described
     in https://datatracker.ietf.org/doc/draft-kazuho-h2-cache-digest/
     Introduced a status handler for HTTP/2 connections, giving various counters
     and statistics about the current connection, plus its cache digest value
     in a JSON record. Not a replacement for more HTTP/2 in the server status.
     Configured as
     <Location "/http2-status">
         SetHandler http2-status
     </Location>
     [Stefan Eissing]

  *) mod_http2: Fixed flushing of last GOAWAY frame. Previously, that frame
     did not always reach the client, causing some to fail the next request.
     Fixed calculation of last stream id accepted as described in rfc7540.
     Reading in KEEPALIVE state now correctly shown in scoreboard.
     Fixed possible race in connection shutdown after review by Ylavic.
     Fixed segfault on connection shutdown, callback ran into a semi dismantled session.
     [Stefan Eissing]

  *) mod_http2: Added support for experimental accept-push-policy draft
     (https://tools.ietf.org/html/draft-ruellan-http-accept-push-policy-00). Clients
     may now influence server pushes by sending accept-push-policy headers.
     [Stefan Eissing]

  *) mod_http2: new r->subprocess_env variables HTTP2 and H2PUSH, set to "on"
     when available for request.
     [Stefan Eissing]

  *) mod_http2: fixed bug in input window size calculation by moving chunked
     request body encoding into later stage of processing. Fixes PR 58825.
     [Stefan Eissing]

  *) core: new hook "pre_close_connection" which is run before the lingering
     close of connections is started. This gives protocol handlers one last
     chance to use a connection before it goes down.
     [Stefan Eissing]

  *) mod_status/scoreboard: showing connection protocol in new column, new
     ap_update_child_status methods for updating server/description. mod_ssl
     sets vhost negotiated by servername directly.
     [Stefan Eissing]

Changes with Apache 2.4.18

  *) mod_ssl: for all ssl_engine_vars.c lookups, fall back to master connection
     if conn_rec itself holds no valid SSLConnRec*. Fixes PR58666.
     [Stefan Eissing]

  *) mod_http2: connection level window for flow control is set to protocol
     maximum of 2GB-1, preventing window exhaustion when sending data on many
     streams with higher cumulative window size.
     Reducing write frequency unless push promises need to be flushed.
     [Stefan Eissing]

  *) mod_http2: required minimum version of libnghttp2 is 1.2.1
     [Stefan Eissing]

  *) mod_proxy_fdpass: Fix AH01153 error when using the default configuration.
     In earlier version of httpd, you can explicitly set the 'flusher' parameter
     to 'flush' as a workaround. (i.e. flusher=flush)
     Add documentation for the 'flusher' parameter when defining a proxy worker.
     [Christophe Jaillet]

  *) mod_ssl: For the "SSLStaplingReturnResponderErrors off" case, make sure
     to only staple responses with certificate status "good". [Kaspar Brand]

  *) mod_http2: new directive 'H2PushPriority' to allow priority specifications
     on server pushed streams according to their content-type.
     [Stefan Eissing]

  *) mod_http2: fixes crash on connection abort for a busy connection.
     fixes crash on a request that did not produce any response.
     [Stefan Eissing]

  *) mod_http2: trailers are sent after response body if set in request_rec
     trailers_out before the end-of-request bucket is sent through the
     output filters. [Stefan Eissing]

  *) mod_http2: incoming trailers (headers after request body) are properly
     forwarded to the processing engine. [Stefan Eissing]

  *) mod_http2: new directive 'H2Push' to en-/disable HTTP/2 server
     pushes a server/virtual host. Pushes are initiated by the presence
     of 'Link:' headers with relation 'preload' on a response. [Stefan Eissing]

  *) mod_http2: write performance of http2 improved for larger resources,
     especially static files. [Stefan Eissing]

  *) core: if the first HTTP/1.1 request on a connection goes to a server that
     prefers different protocols, these protocols are announced in a Upgrade:
     header on the response, mentioning the preferred protocols.
     [Stefan Eissing]

  *) mod_http2: new directives 'H2TLSWarmUpSize' and 'H2TLSCoolDownSecs'
     to control TLS record sizes during connection lifetime.
     [Stefan Eissing]

  *) mod_http2: new directive 'H2ModernTLSOnly' to enforce security
     requirements of RFC 7540 on TLS connections. [Stefan Eissing]

  *) core: add ap_get_protocol_upgrades() to retrieve the list of protocols
     that a client could possibly upgrade to. Use in first request on a
     connection to announce protocol choices. [Stefan Eissing]

  *) mod_http2: reworked deallocation on connection shutdown and worker
     abort. Separate parent pool for all workers. worker threads are joined
     on planned worker shutdown. [Yann Ylavic, Stefan Eissing]

  *) mod_ssl: when receiving requests for other virtual hosts than the handshake
     server, the SSL parameters are checked for equality. With equal
     configuration, requests are passed for processing. Any change will trigger
     the old behaviour of "421 Misdirected Request".
     SSL now remembers the cipher suite that was used for the last handshake.
     This is compared against for any vhost/directory cipher specification.
     Detailed examination of renegotiation is only done when these do not
     match.
     Renegotiation is 403ed when a master connection is present. Exact reason
     is given additionally in a request note. [Stefan Eissing]

  *) mod_ssl: Make the output filter more friendly with deferred write and
     response pipelining. [Yann Ylavic, Joe Orton]

  *) core: Fix scoreboard crash (SIGBUS) on hardware requiring strict 64bit
     alignment (SPARC64, PPC64).  [Yann Ylavic]

  *) mod_cache: Accept HT (Horizontal Tab) when parsing cache related header
     fields as described in RFC7230. [Christophe Jaillet]

  *) core/util_script: making REDIRECT_URL a full URL is now opt-in
     via new 'QualifyRedirectURL' directive.

  *) core: Limit to ten the number of tolerated empty lines between request,
     and consume them before the pipelining check to avoid possible response
     delay when reading the next request without flushing.  [Yann Ylavic]

  *) mod_ssl: Extend expression parser registration to support ssl variables
     in any expression using mod_rewrite syntax "%{SSL:VARNAME}" or function
     syntax "ssl(VARNAME)". [Rainer Jung]

Changes with Apache 2.4.17

  *) mod_http2: added donated HTTP/2 implementation via core module. Similar
     configuration options to mod_ssl. [Stefan Eissing]

  *) mod_proxy: don't recycle backend announced "Connection: close" connections
     to avoid reusing it should the close be effective after some new request
     is ready to be sent.  [Yann Ylavic]

  *) mod_substitute: Allow to configure the patterns merge order with the new
     SubstituteInheritBefore on|off directive.  PR 57641
     [Marc.Stern <Marc.Stern approach.be>, Yann Ylavic, William Rowe]

  *) mod_proxy: Fix ProxySourceAddress binding failure with AH00938.
     PR 56687.  [Arne de Bruijn <apache arbruijn.dds.nl>

  *) mod_ssl: Support compilation against libssl built with OPENSSL_NO_SSL3,
     and change the compiled-in default for SSL[Proxy]Protocol to "all -SSLv3",
     in accordance with RFC 7568. PR 58349, PR 57120. [Kaspar Brand]

  *) mod_ssl: append :!aNULL:!eNULL:!EXP to the cipher string settings,
     instead of prepending !aNULL:!eNULL:!EXP: (as was the case in 2.4.7
     and later). Enables support for configuring the SUITEB* cipher
     strings introduced in OpenSSL 1.0.2. PR 58213. [Kaspar Brand]

  *) mod_ssl: Add support for extracting the msUPN and dnsSRV forms
     of subjectAltName entries of type "otherName" into
     SSL_{CLIENT,SERVER}_SAN_OTHER_{msUPN,dnsSRV}_n environment
     variables. Addresses PR 58020. [Jan Pazdziora <jpazdziora redhat.com>,
     Kaspar Brand]

  *) mod_logio: Fix logging of %^FB (time to first byte) on the first request on
     an SSL connection.  PR 58454.
     [Konstantin J. Chernov <k.j.chernov gmail.com>]

  *) mod_cache: r->err_headers_out is not merged into
     r->headers when mod_cache is enabled and the response
     is cached for the first time. [Edward Lu]

  *) mod_slotmem_shm: Fix slots/SHM files names on restart for systems that
     can't create new (clear) slots while previous children gracefully stopping
     still use the old ones (e.g. Windows, OS2). mod_proxy_balancer failed to
     restart whenever the number of configured balancers/members changed during
     restart.  PR 58024.  [Yann Ylavic]

  *) core/util_script: make REDIRECT_URL a full URL.  PR 57785. [Nick Kew]

  *) MPMs: Support SO_REUSEPORT to create multiple duplicated listener
     records for scalability. [Yingqi Lu <yingqi.lu@intel.com>,
     Jeff Trawick, Jim Jagielski, Yann Ylavic]

  *) mod_alias: Introduce expression parser support for Alias, ScriptAlias
     and Redirect. Limit Redirect expressions to directory (Location) context
     and redirect statuses (implicit or explicit).
     [Graham Leggett, Yann Ylavic, Ruediger Pluem]

  *) mod_proxy: Fix a race condition that caused a failed worker to be retried
     before the retry period is over. [Ruediger Pluem]

  *) mod_autoindex: Allow autoindexes when neither mod_dir nor mod_mime are
     loaded. [Eric Covener]

  *) mod_rewrite:  Allow cookies set by mod_rewrite to contain ':' by accepting
     ';' as an alternate separator.  PR47241.
     [<bugzilla schermesser com>, Eric Covener]

  *) apxs: Add HTTPD_VERSION and HTTPD_MMN to the variables available with
     apxs -q. PR58202. [Daniel Shahaf <danielsh apache.org>]

  *) mod_rewrite: Avoid a crash when lacking correct DB access permissions
     when using RewriteMap with MapType dbd or fastdbd.  [Christophe Jaillet]

  *) mod_authz_dbd: Avoid a crash when lacking correct DB access permissions.
     PR 57868. [Jose Kahan <jose w3.org>, Yann Ylavic]

  *) mod_socache_memcache: Add the 'MemcacheConnTTL' directive to control how
     long to keep idle connections with the memcache server(s).
     Change default value from 600 usec (!) to 15 sec. PR 58091
     [Christophe Jaillet]

  *) mod_dir: Prevent the internal identifier "httpd/unix-directory" from
     appearing as a Content-Type response header when requests for a directory
     are rewritten by mod_rewrite. [Eric Covener]

Changes with Apache 2.4.16

  *) http: Fix LimitRequestBody checks when there is no more bytes to read.
     [Michael Kaufmann <mail michael-kaufmann.ch>]

  *) mod_alias: Revert expression parser support for Alias, ScriptAlias
     and Redirect due to a regression (introduced in 2.4.13, not released).

  *) mod_reqtimeout: Don't let pipelining checks and keep-alive times interfere
     with the timeouts computed for subsequent requests.  PR 56729.
     [Eric Covener, Yann Ylavic]

  *) core: Avoid a possible truncation of the faulty header included in the
     HTML response when LimitRequestFieldSize is reached.  [Yann Ylavic]

  *) mod_ldap: In some case, LDAP_NO_SUCH_ATTRIBUTE could be returned instead
     of an error during a compare operation. [Eric Covener]

Changes with Apache 2.4.15 (not released)

  *) mod_ext_filter, mod_charset_lite: Avoid inadvertent filtering of protocol
     data during read of chunked request bodies. PR 58049.
     [Edward Lu <Chaosed0 gmail.com>]

  *) mod_ldap: Stop leaking LDAP connections when 'LDAPConnectionPoolTTL 0'
     is configured.  PR 58037.  [Ted Phelps <phelps gnusto.com>]

  *) core: Allow spaces after chunk-size for compatibility with implementations
     using a pre-filled buffer.  [Yann Ylavic, Jeff Trawick]

  *) mod_ssl: Remove deprecated SSLCertificateChainFile warning.
     [Yann Ylavic]

Changes with Apache 2.4.14 (not released)

  *) SECURITY: CVE-2015-3183 (cve.mitre.org)
     core: Fix chunk header parsing defect.
     Remove apr_brigade_flatten(), buffering and duplicated code from
     the HTTP_IN filter, parse chunks in a single pass with zero copy.
     Limit accepted chunk-size to 2^63-1 and be strict about chunk-ext
     authorized characters.  [Graham Leggett, Yann Ylavic]

  *) SECURITY: CVE-2015-3185 (cve.mitre.org)
     Replacement of ap_some_auth_required (unusable in Apache httpd 2.4)
     with new ap_some_authn_required and ap_force_authn hook.  [Ben Reser]

Changes with Apache 2.4.13 (not released)

  *) SECURITY: CVE-2015-0253 (cve.mitre.org)
     core: Fix a crash with ErrorDocument 400 pointing to a local URL-path
     with the INCLUDES filter active, introduced in 2.4.11. PR 57531.
     [Yann Ylavic]

  *) SECURITY: CVE-2015-0228 (cve.mitre.org)
     mod_lua: A maliciously crafted websockets PING after a script
     calls r:wsupgrade() can cause a child process crash.
     [Edward Lu <Chaosed0 gmail.com>]

  *) mod_proxy: Don't put the worker in error state for 500 or 503 errors
     returned by the backend unless failonstatus is configured to.  PR 56925.
     [Yann Ylavic]

  *) core: Don't lowercase the argument to SetHandler if it begins with
     "proxy:unix". PR 57968. [Eric Covener]

  *) mod_ssl OCSP Stapling: Don't block initial handshakes while refreshing
     the OCSP response for a different certificate.  mod_ssl has an additional
     global mutex, "ssl-stapling-refresh".  PR 57131 (partial fix).
     [Jeff Trawick]

  *) mod_authz_dbm: Fix crashes when "dbm-file-group" is used and
     authz modules were loaded in the "wrong" order.  [Joe Orton]

  *) mod_authn_dbd, mod_authz_dbd, mod_session_dbd, mod_rewrite: Fix lifetime
     of DB lookup entries independently of the selected DB engine.  PR 46421.
     [Steven whitson <steven.whitson gmail com>, Jan Kaluza, Yann Ylavic].

  *) In alignment with RFC 7525, the default recommended SSLCipherSuite
     and SSLProxyCipherSuite now exclude RC4 as well as MD5. Also, the
     default recommended SSLProtocol and SSLProxyProtocol directives now
     exclude SSLv3. Existing configurations must be adjusted by the
     administrator. [William Rowe]

  *) mod_ssl: Add support for extracting subjectAltName entries of type
     rfc822Name and dNSName into SSL_{CLIENT,SERVER}_SAN_{Email,DNS}_n
     environment variables. Also addresses PR 57207. [Kaspar Brand]

  *) dav_validate_request: avoid validating locks and ETags when there are
     no If headers providing them on a resource we aren't modifying.
     [Ben Reser]

  *) mod_proxy_scgi: ProxySCGIInternalRedirect now allows an alternate
     response header to be used by the application, for when the application
     or framework is unable to return Location in the internal-redirect
     form.  [Jeff Trawick]

  *) core: Cleanup the request soon/even if some output filter fails to
     handle the EOR bucket.  [Yann Ylavic]

  *) mpm_event: Allow for timer events duplicates. [Jim Jagielski, Yann Ylavic]

  *) mod_proxy, mod_ssl, mod_cache_socache, mod_socache_*: Support machine
     readable server-status produced when using the "?auto" query string.
     [Rainer Jung]

  *) mod_status: Add more data to machine readable server-status produced
     when using the "?auto" query string.  [Rainer Jung]

  *) mod_ssl: Check for the Entropy Gathering Daemon (EGD) availability at
     configure time (RAND_egd), and complain if SSLRandomSeed requires using
     it otherwise.  [Bernard Spil <pil.oss gmail com>, Stefan Sperling,
     Kaspar Brand]

  *) mod_ssl: make sure to consistently output SSLCertificateChainFile
     deprecation warnings, when encountered in a VirtualHost block.
     [Falco Schwarz <hiding falco.me>]

  *) mod_log_config: Add "%{UNIT}T" format to output request duration in
     seconds, milliseconds or microseconds depending on UNIT ("s", "ms", "us").
     [Ben Reser, Rainer Jung]

  *) Allow FallbackResource to work when a directory is requested and
     there is no autoindex nor DirectoryIndex.
     [Jack <tjerk.meesters gmail.com>, Eric Covener]

  *) mod_proxy_wstunnel: Bypass the handler while the connection is not
     upgraded to WebSocket, so that other modules can possibly take over
     the leading HTTP requests.  [Yann Ylavic]

  *) mod_http: Fix incorrect If-Match handling. PR 57358
     [Kunihiko Sakamoto <ksakamoto google.com>]

  *) mod_ssl: Add a warning if protocol given in SSLProtocol or SSLProxyProtocol
     will override other parameters given in the same directive. This could be
     a missing + or - prefix.  PR 52820 [Christophe Jaillet]

  *) core, modules: Avoid error response/document handling by the core if some
     handler or input filter already did it while reading the request (causing
     a double response body).  [Yann Ylavic]

  *) mod_proxy_ajp: Fix client connection errors handling and logged status
     when it occurs.  PR 56823.  [Yann Ylavic]

  *) mod_proxy: Use the correct server name for SNI in case the backend
     SSL connection itself is established via a proxy server.
     PR 57139 [Szabolcs Gyurko <szabolcs gyurko.org>]

  *) mod_ssl: Fix possible crash when loading server certificate constraints.
     PR 57694. [Paul Spangler <paul.spangler ni com>, Yann Ylavic]

  *) build: Don't load both mod_cgi and mod_cgid in the default configuration
     if they're both built.  [olli hauer <ohauer gmx.de>]

  *) mod_logio: Add LogIOTrackTTFB and %^FB logformat to log the time
     taken to start writing response headers. [Eric Covener]

  *) mod_ssl: Avoid compilation errors with LibreSSL related to
     the use of ENGINE_CTRL_CHIL_SET_FORKCHECK.
     [Stuart Henderson <sthen openbsd.org>]

  *) mod_proxy_http: Use the "Connection: close" header for requests to
     backends not recycling connections (disablereuse), including the default
     reverse and forward proxies.  [Yann Ylavic]

  *) mod_proxy: Add ap_connection_reusable() for checking if a connection
     is reusable as of this point in processing.  [Jeff Trawick]

  *) mod_proxy_wstunnel: Avoid an empty response by failing with 502 (Bad
     Gateway) when no response is ever received from the backend.
     [Jan Kaluza]

  *) core_filters: Restore/disable TCP_NOPUSH option after non-blocking
     sendfile.  PR 53253.  [Yann Ylavic]

  *) mod_buffer: Forward flushed input data immediately and avoid (unlikely)
     access to freed memory. [Yann Ylavic, Christophe Jaillet]

  *) core: Add CGIPassAuth directive to control whether HTTP authorization
     headers are passed to scripts as CGI variables.  PR 56855.  [Jeff
     Trawick]

  *) core: Initialize scoreboard's used optional functions on graceful restarts
     to avoid a crash when relocation occurs.  PR 57177.  [Yann Ylavic]

  *) mod_dav: Avoid a potential integer underflow in the lock timeout value sent
     back to a client. The answer to a LOCK request could be an extremely large
     integer if the time needed to lock the resource was longer that the
     requested timeout given in the LOCK request. In such a case, we now answer
     "Second-0".  PR55420
     [Christophe Jaillet]

  *) mod_cgid: Within the first minute of a server start or restart,
     allow mod_cgid to retry connecting to its daemon process. Previously,
     'No such file or directory: unable to connect to cgi daemon...' could
     be logged without an actual retry. PR57685.
     [Edward Lu <Chaosed0 gmail.com>]

  *) mod_proxy: Use the original (non absolute) form of the request-line's URI
     for requests embedded in CONNECT payloads used to connect SSL backends via
     a ProxyRemote forward-proxy.  PR 55892.  [Hendrik Harms <hendrik.harms
     gmail com>, William Rowe, Yann Ylavic]

  *) http: Make ap_die() robust against any HTTP error code and not modify
     response status (finally logged) when nothing is to be done. PR 56035.
     [Yann Ylavic]

  *) mod_proxy_connect/wstunnel: If both client and backend sides get readable
     at the same time, don't lose errors occurring while forwarding on the first
     side when none occurs next on the other side, and abort.  [Yann Ylavic]

  *) mod_rewrite: Improve relative substitutions in per-directory/htaccess
     context for directories found by mod_userdir and mod_alias.  These no
     longer require RewriteBase to be specified. [Eric Covener]

  *) mod_proxy_http: Don't expect the backend to ack the "Connection: close" to
     finally close those not meant to be kept alive by SetEnv proxy-nokeepalive
     or force-proxy-request-1.0.  [Yann Ylavic]

  *) core: If explicitly configured, use the KeepaliveTimeout value of the
     virtual host which handled the latest request on the connection, or by
     default the one of the first virtual host bound to the same IP:port.
     PR56226.  [Yann Ylavic]

  *) mod_lua: After a r:wsupgrade(), mod_lua was not properly
     responding to a websockets PING but instead invoking the specified
     script. PR57524. [Edward Lu <Chaosed0 gmail.com>]

  *) mod_ssl: Add the SSL_CLIENT_CERT_RFC4523_CEA variable, which provides
     a combination of certificate serialNumber and issuer as defined by
     CertificateExactMatch in RFC4523. [Graham Leggett]

  *) core: Add expression support to ErrorDocument. Switch from a fixed
     sized 664 byte array per merge to a hash table. [Graham Leggett]

  *) ab: Add missing longest request (100%) to CSV export.
     [Marcin Fabrykowski <bugzilla fabrykowski.pl>]

  *) mod_macro: Clear macros before initialization to avoid use-after-free
     on startup or restart when the module is linked statically. PR 57525
     [apache.org tech.futurequest.net, Yann Ylavic]

  *) mod_alias: Introduce expression parser support for Alias, ScriptAlias
     and Redirect. [Graham Leggett]

  *) mod_ssl: 'SSLProtocol ALL' was being ignored in virtual host context.
     PR 57100.  [Michael Kaufmann <apache-bugzilla michael-kaufmann.ch>,
     Yann Ylavic]

  *) mpm_event: Avoid access to the scoreboard from the connection while
     it is suspended (waiting for events).  [Eric Covener, Jeff Trawick]

  *) mod_ssl: Fix renegotiation failures redirected to an ErrorDocument.
     PR 57334.  [Yann Ylavic].

  *) mod_deflate: A misplaced check prevents limiting small bodies with the
     new inflate limits. PR56872. [Edward Lu, Eric Covener, Yann Ylavic]

  *) mod_proxy_ajp: Forward SSL protocol name (SSLv3, TLSv1.1 etc.) as a
     request attribute to the backend. Recent Tomcat versions will extract
     it and provide it as a servlet request attribute named
     "org.apache.tomcat.util.net.secure_protocol_version". [Rainer Jung]

  *) core: Optimize string concatenation in expression parser when evaluating
     a string expression. [Rainer Jung]

  *) acinclude.m4: Generate #LoadModule directive in default httpd.conf for
     every --enable-mpms-shared. PR 53882.  [olli hauer <ohauer gmx.de>,
     Yann Ylavic]

  *) mod_authn_dbd: Fix the error message logged in case of error while querying
     the database. This is associated to AH01656 and AH01661. [Christophe Jaillet]

  *) mod_authz_groupfile: Reduce the severity of AH01667 from ERROR to DEBUG,
     because it may be evaluated inside <RequireAny>. PR55523. [Eric Covener]

  *) mod_ssl: Fix small memory leak during initialization when ECDH is used.
     [Jan Kaluza]

Changes with Apache 2.4.12

  *) mpm_winnt: Accept utf-8 (Unicode) service names and descriptions for
     internationalization.  [William Rowe]

  *) mpm_winnt: Normalize the error and status messages emitted by service.c,
     the service control interface for Windows.  [William Rowe]

  *) configure: Fix --enable-v4-mapped configuration on *BSD. PR 53824.
     [ olli hauer <ohauer gmx.de>, Yann Ylavic ]

  *) Reverted <DirectoryMatch > behavior regression introduced in 2.4.11
     (not released).

Changes with Apache 2.4.11 (not released)

  *) SECURITY: CVE-2014-3583 (cve.mitre.org)
     mod_proxy_fcgi: Fix a potential crash due to buffer over-read, with
     response headers' size above 8K.  [Yann Ylavic, Jeff Trawick]

  *) SECURITY: CVE-2014-3581 (cve.mitre.org)
     mod_cache: Avoid a crash when Content-Type has an empty value.
     PR 56924.  [Mark Montague <mark catseye.org>, Jan Kaluza]

  *) SECURITY: CVE-2014-8109 (cve.mitre.org)
     mod_lua: Fix handling of the Require line when a LuaAuthzProvider is
     used in multiple Require directives with different arguments.
     PR57204 [Edward Lu <Chaosed0 gmail.com>]

  *) SECURITY: CVE-2013-5704 (cve.mitre.org)
     core: HTTP trailers could be used to replace HTTP headers
     late during request processing, potentially undoing or
     otherwise confusing modules that examined or modified
     request headers earlier.  Adds "MergeTrailers" directive to restore
     legacy behavior.  [Edward Lu, Yann Ylavic, Joe Orton, Eric Covener]

  *) mod_ssl: New directive SSLSessionTickets (On|Off).
     The directive controls the use of TLS session tickets (RFC 5077),
     default value is "On" (unchanged behavior).
     Session ticket creation uses a random key created during web
     server startup and recreated during restarts. No other key
     recreation mechanism is available currently. Therefore using session
     tickets without restarting the web server with an appropriate frequency
     (e.g. daily) compromises perfect forward secrecy. [Rainer Jung]

  *) mod_proxy_fcgi: Provide some basic alternate options for specifying
     how PATH_INFO is passed to FastCGI backends by adding significance to
     the value of proxy-fcgi-pathinfo. PR 55329. [Eric Covener]

  *) mod_proxy_fcgi: Enable UDS backends configured with SetHandler/RewriteRule
     to opt-in to connection reuse and other Proxy options via explicitly
     declared "proxy workers" (<Proxy unix:... enablereuse=on max=...)
     [Eric Covener]

  *) mod_proxy: Add "enablereuse" option as the inverse of "disablereuse".
     [Eric Covener]

  *) mod_proxy_fcgi: Enable opt-in to TCP connection reuse by explicitly
     setting proxy option disablereuse=off. [Eric Covener] PR 57378.

  *) event: Update the internal "connection id" when requests
     move from thread to thread. Reuse can confuse modules like
     mod_cgid. PR 57435. [Michael Thorpe <mike gistnet.com>]

  *) mod_proxy_fcgi: Remove proxy:balancer:// prefix from SCRIPT_FILENAME
     passed to fastcgi backends. [Eric Covener]

  *) core: Configuration files with long lines and continuation characters
     are not read properly. PR 55910. [Manuel Mausz <manuel-as mausz.at>]

  *) mod_include: the 'env' function was incorrectly handled as 'getenv' if the
     leading 'e' was written in upper case in <!--#if expr="..." -->
     statements. [Christophe Jaillet]

  *) split-logfile: Fix perl error:  'Can't use string ("example.org:80")
     as a symbol ref while "strict refs"'. PR 56329.
     [Holger Mauermann <mauermann gmail.com>]

  *) mod_proxy: Prevent ProxyPassReverse from doing a substitution when
     the URL parameter interpolates to an empty string. PR 56603.
     [<ajprout hotmail.com>]

  *) core: Fix -D[efined] or <Define>[d] variables lifetime across restarts.
     PR 57328.  [Armin Abfalterer <a.abfalterer gmail.com>, Yann Ylavic].

  *) mod_proxy: Preserve original request headers even if they differ
     from the ones to be forwarded to the backend. PR 45387.
     [Yann Ylavic]

  *) mod_ssl: dump SSL IO/state for the write side of the connection(s),
     like reads (level TRACE4). [Yann Ylavic]

  *) mod_proxy_fcgi: Ignore body data from backend for 304 responses. PR 57198.
     [Jan Kaluza]

  *) mod_ssl: Do not crash when looking up SSL related variables during
     expression evaluation on non SSL connections. PR 57070  [Ruediger Pluem]

  *) mod_proxy_ajp: Fix handling of the default port (8009) in the
     ProxyPass and <Proxy> configurations.  PR 57259.  [Yann Ylavic]

  *) mpm_event: Avoid a possible use after free when notifying the end of
     connection during lingering close.  PR 57268.  [Eric Covener, Yann Ylavic]

  *) mod_ssl: Fix recognition of OCSP stapling responses that are encoded
     improperly or too large.  [Jeff Trawick]

  *) core: Add ap_log_data(), ap_log_rdata(), etc. for logging buffers.
     [Jeff Trawick]

  *) mod_proxy_fcgi, mod_authnz_fcgi: stop reading the response and issue an
     error when parsing or forwarding the response fails. [Yann Ylavic]

  *) mod_ssl: Fix a memory leak in case of graceful restarts with OpenSSL >= 0.9.8e
     PR 53435 [tadanori <tadanori2007 yahoo.com>, Sebastian Wiedenroth <wiedi frubar.net>]

  *) mod_proxy_connect: Don't issue AH02447 on sockets hangups, let the read
     determine whether it is a normal close or a real error. PR 57168. [Yann
     Ylavic]

  *) mod_proxy_wstunnel: abort backend connection on polling error to avoid
     further processing.  [Yann Ylavic]

  *) core: Support custom ErrorDocuments for HTTP 501 and 414 status codes.
     PR 57167 [Edward Lu <Chaosed0 gmail.com>]

  *) mod_proxy_connect: Fix ProxyRemote to https:// backends on EBCDIC
     systems. PR 57092 [Edward Lu <Chaosed0 gmail.com>]

  *) mod_cache: Avoid a 304 response to an unconditional request when an AH00752
     CacheLock error occurs during cache revalidation. [Eric Covener]

  *) mod_ssl: Move OCSP stapling information from a per-certificate store to
     a per-server hash. PR 54357, PR 56919. [Alex Bligh <alex alex.org.uk>,
     Yann Ylavic, Kaspar Brand]

  *) mod_cache_socache: Change average object size hint from 32 bytes to
     2048 bytes.  [Rainer Jung]

  *) mod_cache_socache: Add cache status to server-status.  [Rainer Jung]

  *) event: Fix worker-listener deadlock in graceful restart.
     PR 56960.

  *) Concat strings at compile time when possible. PR 53741.

  *) mod_substitute: Restrict configuration in .htaccess to
     FileInfo as documented.  [Rainer Jung]

  *) mod_substitute: Make maximum line length configurable.  [Rainer Jung]

  *) mod_substitute: Fix line length limitation in case of regexp plus flatten.
     [Rainer Jung]

  *) mod_proxy: Truncated character worker names are no longer fatal
     errors. PR53218. [Jim Jagielski]

  *) mod_dav: Set r->status_line in dav_error_response. PR 55426.

  *) mod_proxy_http, mod_cache: Avoid (unlikely) accesses to freed memory.
     [Yann Ylavic, Christophe Jaillet]

  *) http_protocol: fix logic in ap_method_list_(add|remove) in order:
       - to correctly reset bits
       - not to modify the 'method_mask' bitfield unnecessarily
     [Christophe Jaillet]

  *) mod_slotmem_shm: Increase log level for some originally debug messages.
     [Jim Jagielski]

  *) mod_ldap: In 2.4.10, some LDAP searches or comparisons might be done with
     the wrong credentials when a backend connection is reused.
     [Eric Covener]

  *) mod_macro: Add missing APLOGNO for some Warning log messages.
     [Christophe Jaillet]

  *) mod_cache: Avoid sending 304 responses during failed revalidations
     PR56881. [Eric Covener]

  *) mod_status: Honor client IP address using mod_remoteip. PR 55886.
     [Jim Jagielski]

  *) cmake-based build for Windows: Fix incompatibility with cmake 2.8.12
     and later.  PR 56615.  [Chuck Liu <cliu81 gmail.com>, Jeff Trawick]

  *) mod_ratelimit: Drop severity of AH01455 and AH01457 (ap_pass_brigade
     failed) messages from ERROR to TRACE1.  Other filters do not bother
     re-reporting failures from lower level filters.  PR56832.  [Eric Covener]

  *) core: Avoid useless warning message when parsing a section guarded by
     <IfDefine foo> if $(foo) is used within the section.
     PR 56503 [Christophe Jaillet]

  *) mod_proxy_fcgi: Fix faulty logging of large amounts of stderr from the
     application.  PR 56858.  [Manuel Mausz <manuel-asf mausz.at>]

  *) mod_proxy_http: Proxy responses with error status and
     "ProxyErrorOverride On" hang until proxy timeout.
     PR53420 [Rainer Jung]

  *) mod_log_config: Allow three character log formats to be registered. For
     backwards compatibility, the first character of a three-character format
     must be the '^' (caret) character.  [Eric Covener]

  *) mod_lua: Don't quote Expires and Path values. PR 56734.
     [Keith Mashinter, <kmashint yahoo com>]

  *) mod_authz_core: Allow <AuthzProviderAlias>'es to be seen from auth
     stanzas under virtual hosts. PR 56870. [Eric Covener]

Changes with Apache 2.4.10

  *) SECURITY: CVE-2014-0117 (cve.mitre.org)
     mod_proxy: Fix crash in Connection header handling which allowed a denial
     of service attack against a reverse proxy with a threaded MPM.
     [Ben Reser]

  *) SECURITY: CVE-2014-3523 (cve.mitre.org)
     Fix a memory consumption denial of service in the WinNT MPM, used in all
     Windows installations. Workaround: AcceptFilter <protocol> {none|connect}
     [Jeff Trawick]

  *) SECURITY: CVE-2014-0226 (cve.mitre.org)
     Fix a race condition in scoreboard handling, which could lead to
     a heap buffer overflow.  [Joe Orton, Eric Covener]

  *) SECURITY: CVE-2014-0118 (cve.mitre.org)
     mod_deflate: The DEFLATE input filter (inflates request bodies) now
     limits the length and compression ratio of inflated request bodies to
     avoid denial of service via highly compressed bodies.  See directives
     DeflateInflateLimitRequestBody, DeflateInflateRatioLimit,
     and DeflateInflateRatioBurst. [Yann Ylavic, Eric Covener]

  *) SECURITY: CVE-2014-0231 (cve.mitre.org)
     mod_cgid: Fix a denial of service against CGI scripts that do
     not consume stdin that could lead to lingering HTTPD child processes
     filling up the scoreboard and eventually hanging the server.  By
     default, the client I/O timeout (Timeout directive) now applies to
     communication with scripts.  The CGIDScriptTimeout directive can be
     used to set a different timeout for communication with scripts.
     [Rainer Jung, Eric Covener, Yann Ylavic]

  *) mod_ssl: Extend the scope of SSLSessionCacheTimeout to sessions
     resumed by TLS session resumption (RFC 5077). [Rainer Jung]

  *) mod_deflate: Don't fail when flushing inflated data to the user-agent
     and that coincides with the end of stream ("Zlib error flushing inflate
     buffer"). PR 56196. [Christoph Fausak <christoph fausak glueckkanja.com>]

  *) mod_proxy_ajp: Forward local IP address as a custom request attribute
     like we already do for the remote port. [Rainer Jung]

  *) core: Include any error notes set by modules in the canned error
     response for 403 errors.  [Jeff Trawick]

  *) mod_ssl: Set an error note for requests rejected due to
     SSLStrictSNIVHostCheck.  [Jeff Trawick]

  *) mod_ssl: Fix issue with redirects to error documents when handling
     SNI errors.  [Jeff Trawick]

  *) mod_ssl: Fix tmp DH parameter leak, adjust selection to prefer
     larger keys and support up to 8192-bit keys.  [Ruediger Pluem,
     Joe Orton]

  *) mod_dav: Fix improper encoding in PROPFIND responses.  PR 56480.
     [Ben Reser]

  *) WinNT MPM: Improve error handling for termination events in child.
     [Jeff Trawick]

  *) mod_proxy: When ping/pong is configured for a worker, don't send or
     forward "100 Continue" (interim) response to the client if it does
     not expect one. [Yann Ylavic]

  *) mod_ldap: Be more conservative with the last-used time for
     LDAPConnectionPoolTTL. PR54587 [Eric Covener]

  *) mod_ldap: LDAP connections used for authn were not respecting
     LDAPConnectionPoolTTL. PR54587 [Eric Covener]

  *) mod_proxy_fcgi: Fix occasional high CPU when handling request bodies.
     [Jeff Trawick]

  *) event MPM: Fix possible crashes (third-party modules accessing c->sbh)
     or occasional missed mod_status updates under load. PR 56639.
     [Edward Lu <Chaosed0 gmail com>]

  *) mod_authnz_ldap: Support primitive LDAP servers do not accept
     filters, such as "SDBM-backed LDAP" on z/OS, by allowing a special
     filter "none" to be specified in AuthLDAPURL. [Eric Covener]

  *) mod_deflate: Fix inflation of files larger than 4GB. PR 56062.
     [Lukas Bezdicka <social v3.sk>]

  *) mod_deflate: Handle Zlib header and validation bytes received in multiple
     chunks. PR 46146. [Yann Ylavic]

  *) mod_proxy: Allow reverse-proxy to be set via explicit handler.
     [ryo takatsuki <ryotakatsuki gmail com>]

  *) ab: support custom HTTP method with -m argument. PR 56604.
     [Roman Jurkov <winfinit gmail.com>]

  *) mod_proxy_balancer: Correctly encode user provided data in management
     interface. PR 56532 [Maksymilian, <max cert.cx>]

  *) mod_proxy: Don't limit the size of the connectable Unix Domain Socket
     paths. [Graham Dumpleton, Christophe Jaillet, Yann Ylavic]

  *) mod_proxy_fcgi: Support iobuffersize parameter.  [Jeff Trawick]

  *) event: Send the SSL close notify alert when the KeepAliveTimeout
     expires. PR54998. [Yann Ylavic]

  *) mod_ssl: Ensure that the SSL close notify alert is flushed to the client.
     PR54998. [Tim Kosse <tim.kosse filezilla-project.org>, Yann Ylavic]

  *) mod_proxy: Shutdown (eg. SSL close notify) the backend connection before
     closing. [Yann Ylavic]

  *) mod_auth_form: Add a debug message when the fields on a form are not
     recognised. [Graham Leggett]

  *) mod_cache: Preserve non-cacheable headers forwarded from an origin 304
     response. PR 55547.  [Yann Ylavic]

  *) mod_proxy_wstunnel: Fix the use of SSL connections with the "wss:"
     scheme. PR55320. [Alex Liu <alex.leo.ca gmail.com>]

  *) mod_socache_shmcb: Correct counting of expirations for status display.
     Expirations happening during retrieval were not counted. [Rainer Jung]

  *) mod_cache: Retry unconditional request with the full URL (including the
     query-string) when the origin server's 304 response does not match the
     conditions used to revalidate the stale entry.  [Yann Ylavic].

  *) mod_alias: Stop setting CONTEXT_PREFIX and CONTEXT_DOCUMENT environment
     variables as a result of AliasMatch. [Eric Covener]

  *) mod_cache: Don't add cached/revalidated entity headers to a 304 response.
     PR 55547.  [Yann Ylavic]

  *) mod_proxy_scgi: Support Unix sockets.  ap_proxy_port_of_scheme():
     Support default SCGI port (4000).  [Jeff Trawick]

  *) mod_cache: Fix AH00784 errors on Windows when the the CacheLock directive
     is enabled.  [Eric Covener]

  *) mod_expires: don't add Expires header to error responses (4xx/5xx),
     be they generated or forwarded. PR 55669.  [Yann Ylavic]

  *) mod_proxy_fcgi: Don't segfault when failing to connect to the backend.
     (regression in 2.4.9 release) [Jeff Trawick]

  *) mod_authn_socache: Fix crash at startup in certain configurations.
     PR 56371. (regression in 2.4.7) [Jan Kaluza]

  *) mod_ssl: restore argument structure for "exec"-type SSLPassPhraseDialog
     programs to the form used in releases up to 2.4.7, and emulate
     a backwards-compatible behavior for existing setups. [Kaspar Brand]

  *) mod_ssl: Add SSLOCSPUseRequestNonce directive to control whether or not
     OCSP requests should use a nonce to be checked against the responder's
     one. PR 56233. [Yann Ylavic, Kaspar Brand]

  *) mod_ssl: "SSLEngine off" will now override a Listen-based default
     and does disable mod_ssl for the vhost.  [Joe Orton]

  *) mod_lua: Enforce the max post size allowed via r:parsebody()
     [Daniel Gruno]

  *) mod_lua: Use binary comparison to find boundaries for multipart
     objects, as to not terminate our search prematurely when hitting
     a NULL byte. [Daniel Gruno]

  *) mod_ssl: add workaround for SSLCertificateFile when using OpenSSL
     versions before 0.9.8h and not specifying an SSLCertificateChainFile
     (regression introduced with 2.4.8). PR 56410. [Kaspar Brand]

  *) mod_ssl: bring SNI behavior into better conformance with RFC 6066:
     no longer send warning-level unrecognized_name(112) alerts,
     and limit startup warnings to cases where an OpenSSL version
     without TLS extension support is used. PR 56241. [Kaspar Brand]

  *) mod_proxy_html: Avoid some possible memory access violation in case of
     specially crafted files, when the ProxyHTMLMeta directive is turned on.
     Follow up of PR 56287 [Christophe Jaillet]

  *) mod_auth_form: Make sure the optional functions are loaded even when
     the AuthFormProvider isn't specified. [Graham Leggett]

  *) mod_ssl: avoid processing bogus SSLCertificateKeyFile values
     (and logging garbled file names). PR 56306. [Kaspar Brand]

  *) mod_ssl: fix merging of global and vhost-level settings with the
     SSLCertificateFile, SSLCertificateKeyFile, and SSLOpenSSLConfCmd
     directives. PR 56353. [Kaspar Brand]

  *) mod_headers: Allow the "value" parameter of Header and RequestHeader to
     contain an ap_expr expression if prefixed with "expr=". [Eric Covener]

  *) rotatelogs: Avoid creation of zombie processes when -p is used on
     Unix platforms.  [Joe Orton]

  *) mod_authnz_fcgi: New module to enable FastCGI authorizer
     applications to authenticate and/or authorize clients.
     [Jeff Trawick]

  *) mod_proxy: Do not try to parse the regular expressions passed by
     ProxyPassMatch as URL as they do not follow their syntax.
     PR 56074. [Ruediger Pluem]

  *) mod_reqtimeout: Resolve unexpected timeouts on keepalive requests
     under the Event MPM. PR56216.  [Frank Meier <frank meier ergon ch>]

  *) mod_proxy_fcgi: Fix sending of response without some HTTP headers
     that might be set by filters.  PR 55558. [Jim Riggs <jim riggs.me>]

  *) mod_proxy_html: Do not delete the wrong data from HTML code when a
     "http-equiv" meta tag specifies a Content-Type behind any other
     "http-equiv" meta tag. PR 56287 [Micha Lenk <micha lenk info>]

  *) mod_proxy: Don't reuse a SSL backend connection whose requested SNI
     differs. PR 55782.  [Yann Ylavic]

  *) Add suspend_connection and resume_connection hooks to notify modules
     when the thread/connection relationship changes.  (Should be implemented
     for any third-party async MPMs.)  [Jeff Trawick]

  *) mod_proxy_wstunnel: Don't issue AH02447 and log a 500 on routine
     hangups from websockets origin servers. PR 56299
     [Yann Ylavic, Edward Lu <Chaosed0 gmail com>, Eric Covener]

  *) mod_proxy_wstunnel: Don't pool backend websockets connections,
     because we need to handshake every time. PR 55890.
     [Eric Covener]

  *) mod_lua: Redesign how request record table access behaves,
     in order to utilize the request record from within these tables.
     [Daniel Gruno]

  *) mod_lua: Add r:wspeek for peeking at WebSocket frames. [Daniel Gruno]

  *) mod_lua: Log an error when the initial parsing of a Lua file fails.
     [Daniel Gruno, Felipe Daragon <filipe syhunt com>]

  *) mod_lua: Reformat and escape script error output.
     [Daniel Gruno, Felipe Daragon <filipe syhunt com>]

  *) mod_lua: URL-escape cookie keys/values to prevent tainted cookie data
     from causing response splitting.
     [Daniel Gruno, Felipe Daragon <filipe syhunt com>]

  *) mod_lua: Disallow newlines in table values inside the request_rec,
     to prevent HTTP Response Splitting via tainted headers.
     [Daniel Gruno, Felipe Daragon <filipe syhunt com>]

  *) mod_lua: Remove the non-working early/late arguments for
     LuaHookCheckUserID. [Daniel Gruno]

  *) mod_lua: Change IVM storage to use shm [Daniel Gruno]

  *) mod_lua: More verbose error logging when a handler function cannot be
     found. [Daniel Gruno]

Changes with Apache 2.4.9

  *) mod_ssl: Work around a bug in some older versions of OpenSSL that
     would cause a crash in SSL_get_certificate for servers where the
     certificate hadn't been sent. [Stephen Henson]

  *) mod_lua: Add a fixups hook that checks if the original request is intended
     for LuaMapHandler. This fixes a bug where FallbackResource invalidates the
     LuaMapHandler directive in certain cases by changing the URI before the map
     handler code executes [Daniel Gruno, Daniel Ferradal <dferradal gmail com>].

Changes with Apache 2.4.8 (not released)

  *) SECURITY: CVE-2014-0098 (cve.mitre.org)
     Clean up cookie logging with fewer redundant string parsing passes.
     Log only cookies with a value assignment. Prevents segfaults when
     logging truncated cookies.
     [William Rowe, Ruediger Pluem, Jim Jagielski]

  *) SECURITY: CVE-2013-6438 (cve.mitre.org)
     mod_dav: Keep track of length of cdata properly when removing
     leading spaces. Eliminates a potential denial of service from
     specifically crafted DAV WRITE requests
     [Amin Tora <Amin.Tora neustar.biz>]

  *) core: Support named groups and backreferences within the LocationMatch,
     DirectoryMatch, FilesMatch and ProxyMatch directives. (Requires
     non-ancient PCRE library) [Graham Leggett]

  *) core: draft-ietf-httpbis-p1-messaging-23 corrections regarding
     TE/CL conflicts. [Yann Ylavic, Jim Jagielski]

  *) core: Detect incomplete request and response bodies, log an error and
     forward it to the underlying filters. PR 55475 [Yann Ylavic]

  *) mod_dir: Add DirectoryCheckHandler to allow a 2.2-like behavior, skipping
     execution when a handler is already set. PR53929. [Eric Covener]

  *) mod_ssl: Do not perform SNI / Host header comparison in case of a
     forward proxy request. [Ruediger Pluem]

  *) mod_ssl: Remove the hardcoded algorithm-type dependency for the
     SSLCertificateFile and SSLCertificateKeyFile directives, to enable
     future algorithm agility, and deprecate the SSLCertificateChainFile
     directive (obsoleted by SSLCertificateFile). [Kaspar Brand]

  *) mod_rewrite: Add RewriteOptions InheritDown, InheritDownBefore,
     and IgnoreInherit to allow RewriteRules to be pushed from parent scopes
     to child scopes without explicitly configuring each child scope.
     PR56153.  [Edward Lu <Chaosed0 gmail com>]

  *) prefork: Fix long delays when doing a graceful restart.
     PR 54852 [Jim Jagielski, Arkadiusz Miskiewicz <arekm maven pl>]

  *) FreeBSD: Disable IPv4-mapped listening sockets by default for versions
     5+ instead of just for FreeBSD 5. PR 53824. [Jeff Trawick]

  *) mod_proxy_wstunnel: Avoid busy loop on client errors, drop message
     IDs 02445, 02446, and 02448 to TRACE1 from DEBUG. PR 56145.
     [Joffroy Christen <joffroy.christen solvaxis com>, Eric Covener]

  *) mod_remoteip: Correct the trusted proxy match test. PR 54651.
     [Yoshinori Ehara <yoshinori ehara gmail com>, Eugene L <eugenel amazon com>]

  *) mod_proxy_fcgi: Fix error message when an unexpected protocol version
     number is received from the application.  PR 56110.  [Jeff Trawick]

  *) mod_remoteip: Use the correct IP addresses to populate the proxy_ips field.
     PR 55972. [Mike Rumph]

  *) mod_lua: Update r:setcookie() to accept a table of options and add domain,
     path and httponly to the list of options available to set.
     PR 56128 [Edward Lu <Chaosed0 gmail com>, Daniel Gruno]

  *) mod_lua: Fix r:setcookie() to add, rather than replace,
     the Set-Cookie header. PR56105
     [Kevin J Walters <kjw ms com>, Edward Lu <Chaosed0 gmail com>]

  *) mod_lua: Allow for database results to be returned as a hash with
     row-name/value pairs instead of just row-number/value. [Daniel Gruno]

  *) mod_rewrite: Add %{CONN_REMOTE_ADDR} as the non-useragent counterpart to
     %{REMOTE_ADDR}. PR 56094. [Edward Lu <Chaosed0 gmail com>]

  *) WinNT MPM: If ap_run_pre_connection() fails or sets c->aborted, don't
     save the socket for reuse by the next worker as if it were an
     APR_SO_DISCONNECTED socket. Restores 2.2 behavior. [Eric Covener]

  *) mod_dir: Don't search for a DirectoryIndex or DirectorySlash on a URL
     that was just rewritten by mod_rewrite. PR53929. [Eric Covener]

  *) mod_session: When we have a session we were unable to decode,
     behave as if there was no session at all. [Thomas Eckert
     <thomas.r.w.eckert gmail com>]

  *) mod_session: Fix problems interpreting the SessionInclude and
     SessionExclude configuration. PR 56038. [Erik Pearson
     <erik adaptations.com>]

  *) mod_authn_core: Allow <AuthnProviderAlias>'es to be seen from auth
     stanzas under virtual hosts. PR 55622. [Eric Covener]

  *) mod_proxy_fcgi: Use apr_socket_timeout_get instead of hard-coded
     30 seconds timeout. [Jan Kaluza]

  *) build: only search for modules (config*.m4) in known subdirectories, see
     build/config-stubs. [Stefan Fritsch]

  *) mod_cache_disk: Fix potential hangs on Windows when using mod_cache_disk.
     PR 55833. [Eric Covener]

  *) mod_ssl: Add support for OpenSSL configuration commands by introducing
     the SSLOpenSSLConfCmd directive. [Stephen Henson, Kaspar Brand]

  *) mod_proxy: Remove (never documented) <Proxy ~ wildcard-url> syntax which
     is equivalent to <ProxyMatch wildcard-url>. [Christophe Jaillet]

  *) mod_authz_user, mod_authz_host, mod_authz_groupfile, mod_authz_dbm,
     mod_authz_dbd, mod_authnz_ldap: Support the expression parser within the
     require directives. [Graham Leggett]

  *) mod_proxy_http: Core dumped under high load. PR 50335.
     [Jan Kaluza <jkaluza redhat.com>]

  *) mod_socache_shmcb.c: Remove arbitrary restriction on shared memory size
     previously limited to 64MB. [Jens Låås <jelaas gmail.com>]

  *) mod_lua: Use binary copy when dealing with uploads through r:parsebody()
     to prevent truncating files. [Daniel Gruno]

Changes with Apache 2.4.7

  *) SECURITY: CVE-2013-4352 (cve.mitre.org)
     mod_cache: Fix a NULL pointer deference which allowed untrusted
     origin servers to crash mod_cache in a forward proxy
     configuration.  [Graham Leggett]

  *) APR 1.5.0 or later is now required for the event MPM.

  *) slotmem_shm: Error detection. [Jim Jagielski]

  *) event: Use skiplist data structure. [Jim Jagielski]

  *) event: Fail at startup with message AP02405 if the APR atomic
     implementation is not compatible with the MPM.  [Jim Jagielski]

  *) mpm_unix: Add ap_mpm_podx_* implementation to avoid code duplication
     and align w/ trunk. [Jim Jagielski]

  *) Fix potential rejection of valid MaxMemFree and ThreadStackSize
     directives.  [Mike Rumph <mike.rumph oracle.com>]

  *) mod_proxy_fcgi: Remove 64K limit on encoded length of all envvars.
     An individual envvar with an encoded length of more than 16K will be
     omitted.  [Jeff Trawick]

  *) mod_proxy_fcgi: Handle reading protocol data that is split between
     packets.  [Jeff Trawick]

  *) mod_ssl: Improve handling of ephemeral DH and ECDH keys by
     allowing custom parameters to be configured via SSLCertificateFile,
     and by adding standardized DH parameters for 1024/2048/3072/4096 bits.
     Unless custom parameters are configured, the standardized parameters
     are applied based on the certificate's RSA/DSA key size. [Kaspar Brand]

  *) mod_ssl, configure: Require OpenSSL 0.9.8a or later. [Kaspar Brand]

  *) mod_ssl: drop support for export-grade ciphers with ephemeral RSA
     keys, and unconditionally disable aNULL, eNULL and EXP ciphers
     (not overridable via SSLCipherSuite). [Kaspar Brand]

  *) mod_proxy: Added support for unix domain sockets as the
     backend server endpoint. This also introduces an unintended
     incompatibility for third party modules using the mod_proxy
     proxy_worker_shared structure, especially for balancer lbmethod
     modules. [Jim Jagielski, Blaise Tarr <blaise tarr gmail com>]

  *) Add experimental cmake-based build system for Windows.  [Jeff Trawick,
     Tom Donovan]

  *) event MPM: Fix possible crashes (third party modules accessing c->sbh)
     or occasional missed mod_status updates for some keepalive requests
     under load. [Eric Covener]

  *) mod_authn_socache: Support optional initialization arguments for
     socache providers.  [Chris Darroch]

  *) mod_session: Reset the max-age on session save. PR 47476. [Alexey
     Varlamov <alexey.v.varlamov gmail com>]

  *) mod_session: After parsing the value of the header specified by the
     SessionHeader directive, remove the value from the response. PR 55279.
     [Graham Leggett]

  *) mod_headers: Allow for format specifiers in the substitution string
     when using Header edit. [Daniel Ruggeri]

  *) mod_dav: dav_resource->uri is treated as unencoded. This was an
     unnecessary ABI changed introduced in 2.4.6. PR 55397.

  *) mod_dav: Don't require lock tokens for COPY source. PR 55306.

  *) core: Don't truncate output when sending is interrupted by a signal,
     such as from an exiting CGI process. PR 55643. [Jeff Trawick]

  *) WinNT MPM: Exit the child if the parent process crashes or is terminated.
     [Oracle Corporation]

  *) Windows: Correct failure to discard stderr in some error log
     configurations.  (Error message AH00093)  [Jeff Trawick]

  *) mod_session_crypto: Allow using exec: calls to obtain session
     encryption key.  [Daniel Ruggeri]

  *) core: Add missing Reason-Phrase in HTTP response headers.
     PR 54946. [Rainer Jung]

  *) mod_rewrite: Make rewrite websocket-aware to allow proxying.
     PR 55598. [Chris Harris <chris.harris kitware com>]

  *) mod_ldap: When looking up sub-groups, use an implicit objectClass=*
     instead of an explicit cn=* filter. [David Hawes <dhawes vt.edu>]

  *) ab: Add wait time, fix processing time, and output write errors only if
     they occurred. [Christophe Jaillet]

  *) worker MPM: Don't forcibly kill worker threads if the child process is
     exiting gracefully.  [Oracle Corporation]

  *) core: apachectl -S prints wildcard name-based virtual hosts twice.
     PR54948 [Eric Covener]

  *) mod_auth_basic: Add AuthBasicUseDigestAlgorithm directive to
     allow migration of passwords from digest to basic authentication.
     [Chris Darroch]

  *) ab: Add a new -l parameter in order not to check the length of the responses.
     This can be useful with dynamic pages.
     PR9945, PR27888, PR42040 [<ccikrs1 cranbrook edu>]

  *) Suppress formatting of startup messages written to the console when
     ErrorLogFormat is used.  [Jeff Trawick]

  *) mod_auth_digest: Be more specific when the realm mismatches because the
     realm has not been specified. [Graham Leggett]

  *) mod_proxy: Add a note in the balancer manager stating whether changes
     will or will not be persisted and whether settings are inherited.
     [Daniel Ruggeri, Jim Jagielski]

  *) core: Add util_fcgi.h and associated definitions and support
     routines for FastCGI, based largely on mod_proxy_fcgi.
     [Jeff Trawick]

  *) mod_headers: Add 'Header note header-name note-name' for copying a response
     headers value into a note. [Eric Covener]

  *) mod_headers: Add 'setifempty' command to Header and RequestHeader.
     [Eric Covener]

  *) mod_logio: new format-specifier %S (sum) which is the sum of received
     and sent byte counts.
     PR54015 [Christophe Jaillet]

  *) mod_deflate: Improve error detection when decompressing request bodies
     with trailing garbage: handle case where trailing bytes are in
     the same bucket. [Rainer Jung]

  *) mod_authz_groupfile, mod_authz_user: Reduce severity of AH01671 and AH01663
     from ERROR to DEBUG, since these modules do not know what mod_authz_core
     is doing with their AUTHZ_DENIED return value. [Eric Covener]

  *) mod_ldap: add TRACE5 for LDAP retries. [Eric Covener]

  *) mod_ldap: retry on an LDAP timeout during authn. [Eric Covener]

  *) mod_ldap: Change "LDAPReferrals off" to actually set the underlying LDAP
     SDK option to OFF, and introduce "LDAPReferrals default" to take the SDK
     default, sans rebind authentication callback.
     [Jan Kaluza <kaluze AT redhat.com>]

  *) core: Log a message at TRACE1 when the client aborts a connection.
     [Eric Covener]

  *) WinNT MPM: Don't crash during child process initialization if the
     Listen protocol is unrecognized.  [Jeff Trawick]

  *) modules: Fix some compiler warnings. [Guenter Knauf]

  *) Sync 2.4 and trunk
       - Avoid some memory allocation and work when TRACE1 is not activated
       - fix typo in include guard
       - indent
       - No need to lower the string before removing the path, it is just
         a waste of time...
       - Save a few cycles
     [Christophe Jaillet <christophe.jaillet wanadoo.fr>]

  *) mod_filter: Add "change=no" as a proto-flag to FilterProtocol
     to remove a providers initial flags set at registration time.
     [Eric Covener]

  *) core, mod_ssl: Enable the ability for a module to reverse the sense of
     a poll event from a read to a write or vice versa. This is a step on
     the way to allow mod_ssl taking full advantage of the event MPM.
     [Graham Leggett]

  *) Makefile.win: Install proper pcre DLL file during debug build install.
     PR 55235.  [Ben Reser <ben reser org>]

  *) mod_ldap: Fix a potential memory leak or corruption.  PR 54936.
     [Zhenbo Xu <zhenbo1987 gmail com>]

  *) ab: Fix potential buffer overflows when processing the T and X
     command-line options.  PR 55360.
     [Mike Rumph <mike.rumph oracle.com>]

  *) fcgistarter: Specify SO_REUSEADDR to allow starting a server
     with old connections in TIME_WAIT.  [Jeff Trawick]

  *) core: Add open_htaccess hook which, in conjunction with dirwalk_stat
     and post_perdir_config (introduced in 2.4.5), allows mpm-itk to be
     used without patches to httpd core. [Stefan Fritsch]

  *) support/htdbm: fix processing of -t command line switch. Regression
     introduced in 2.4.4
     PR 55264 [Jo Rhett <jrhett netconsonance com>]

  *) mod_lua: add websocket support via r:wsupgrade, r:wswrite, r:wsread
     and r:wsping. [Daniel Gruno]

  *) mod_lua: add support for writing/reading cookies via r:getcookie and
     r:setcookie. [Daniel Gruno]

  *) mod_lua: If the first yield() of a LuaOutputFilter returns a string, it should
     be prefixed to the response as documented. [Eric Covener]
     Note: Not present in 2.4.7 CHANGES

  *) mod_lua: Remove ETAG, Content-Length, and Content-MD5 when a LuaOutputFilter
     is configured without mod_filter. [Eric Covener]
     Note: Not present in 2.4.7 CHANGES

  *) mod_lua: Register LuaOutputFilter scripts as changing the content and
     content-length by default, when run my mod_filter.  Previously,
     growing or shrinking a response that started with Content-Length set
     would require mod_filter and FilterProtocol change=yes. [Eric Covener]
     Note: Not present in 2.4.7 CHANGES

  *) mod_lua: Return a 500 error if a LuaHook* script doesn't return a
     numeric return code. [Eric Covener]
     Note: Not present in 2.4.7 CHANGES

Changes with Apache 2.4.6

  *) Revert a broken fix for PR54948 that was applied to 2.4.5 (which was
     not released) and found post-2.4.5 tagging.

Changes with Apache 2.4.5

  *) SECURITY: CVE-2013-1896 (cve.mitre.org)
     mod_dav: Sending a MERGE request against a URI handled by mod_dav_svn with
     the source href (sent as part of the request body as XML) pointing to a
     URI that is not configured for DAV will trigger a segfault. [Ben Reser
     <ben reser.org>]

  *) SECURITY: CVE-2013-2249 (cve.mitre.org)
     mod_session_dbd: Make sure that dirty flag is respected when saving
     sessions, and ensure the session ID is changed each time the session
     changes. This changes the format of the updatesession SQL statement.
     Existing configurations must be changed.
     [Takashi Sato, Graham Leggett]

  *) mod_auth_basic: Add a generic mechanism to fake basic authentication
     using the ap_expr parser. AuthBasicFake allows the administrator to
     construct their own username and password for basic authentication based
     on their needs. [Graham Leggett]

  *) mpm_event: Check that AsyncRequestWorkerFactor is not negative. PR 54254.
     [Jackie Zhang <jackie qq zhang gmail com>]

  *) mod_proxy: Ensure we don't attempt to amend a table we are iterating
     through, ensuring that all headers listed by Connection are removed.
     [Graham Leggett, Co-Advisor <coad measurement-factory.com>]

  *) mod_proxy_http: Make the proxy-interim-response environment variable
     effective by formally overriding origin server behaviour. [Graham
     Leggett, Co-Advisor <coad measurement-factory.com>]

  *) mod_proxy: Fix seg-faults when using the global pool on threaded
     MPMs [Thomas Eckert <thomas.r.w.eckert gmail.com>, Graham Leggett,
     Jim Jagielski]

  *) mod_deflate: Remove assumptions as to when an EOS bucket might arrive.
     Gracefully step aside if the body size is zero. [Graham Leggett]

  *) mod_ssl: Fix possible truncation of OCSP responses when reading from the
     server.  [Joe Orton]

  *) core: Support the SINGLE_LISTEN_UNSERIALIZED_ACCEPT optimization
     on Linux kernel versions 3.x and above.  PR 55121.  [Bradley Heilbrun
     <apache heilbrun.org>]

  *) mod_cache_socache: Make sure the CacheSocacheMaxSize directive is merged
     correctly. [Jens Låås <jelaas gmail.com>]

  *) rotatelogs: add -n number-of-files option to rotate through a number
     of fixed-name logfiles. [Eric Covener]

  *) mod_proxy: Support web-socket tunnels via mod_proxy_wstunnel.
     [Jim Jagielski]

  *) mod_cache_socache: Use the name of the socache implementation when performing
     a lookup rather than using the raw arguments. [Martin Ksellmann
     <martin@ksellmann.de>]

  *) core: Add dirwalk_stat hook.  [Jeff Trawick]

  *) core: Add post_perdir_config hook.
     [Steinar Gunderson <sgunderson bigfoot.com>]

  *) proxy_util: NULL terminate the right buffer in 'send_http_connect'.
     [Christophe Jaillet]

  *) mod_remoteip: close file in error path. [Christophe Jaillet]

  *) core: make the "default" parameter of the "ErrorDocument" option case
     insensitive. PR 54419 [Tianyin Xu <tixu cs ucsd edu>]

  *) mod_proxy_html: make the "ProxyHTMLFixups" options case insensitive.
     PR 54420 [Tianyin Xu <tixu cs ucsd edu>]

  *) mod_cache: Make option "CacheDisable" in mod_cache case insensitive.
     PR 54462 [Tianyin Xu <tixu cs ucsd edu>]

  *) mod_cache: If a 304 response indicates an entity not currently cached, then
     the cache MUST disregard the response and repeat the request without the
     conditional. [Graham Leggett, Co-Advisor <coad measurement-factory.com>]

  *) mod_cache: Ensure that we don't attempt to replace a cached response
     with an older response as per RFC2616 13.12. [Graham Leggett, Co-Advisor
     <coad measurement-factory.com>]

  *) core, mod_cache: Ensure RFC2616 compliance in ap_meets_conditions()
     with weak validation combined with If-Range and Range headers. Break
     out explicit conditional header checks to be useable elsewhere in the
     server. Ensure weak validation RFC compliance in the byteranges filter.
     Ensure RFC validation compliance when serving cached entities. PR 16142
     [Graham Leggett, Co-Advisor <coad measurement-factory.com>]

  *) core: Add the ability to do explicit matching on weak and strong ETags
     as per RFC2616 Section 13.3.3. [Graham Leggett, Co-Advisor
     <coad measurement-factory.com>]

  *) mod_cache: Ensure that updated responses to HEAD requests don't get
     mistakenly paired with a previously cached body. Ensure that any existing
     body is removed when a HEAD request is cached. [Graham Leggett,
     Co-Advisor <coad measurement-factory.com>]

  *) mod_cache: Honour Cache-Control: no-store in a request. [Graham Leggett]

  *) mod_cache: Make sure that contradictory entity headers present in a 304
     Not Modified response are caught and cause the entity to be removed.
     [Graham Leggett]

  *) mod_cache: Make sure Vary processing handles multivalued Vary headers and
     multivalued headers referred to via Vary. [Graham Leggett]

  *) mod_cache: When serving from cache, only the last header of a multivalued
     header was taken into account. Fixed. Ensure that Warning headers are
     correctly handled as per RFC2616. [Graham Leggett]

  *) mod_cache: Ignore response headers specified by no-cache=header and
     private=header as specified by RFC2616 14.9.1 What is Cacheable. Ensure
     that these headers are still processed when multiple Cache-Control
     headers are present in the response. PR 54706 [Graham Leggett,
     Yann Ylavic <ylavic.dev gmail.com>]

  *) mod_cache: Invalidate cached entities in response to RFC2616 Section
     13.10 Invalidation After Updates or Deletions. PR 15868 [Graham
     Leggett]

  *) mod_dav: Improve error handling in dav_method_put(), add new
     dav_join_error() function.  PR 54145.  [Ben Reser <ben reser.org>]

  *) mod_dav: Do not fail PROPPATCH when prop namespace is not known.
     PR 52559 [Diego Santa Cruz <diego.santaCruz spinetix.com>]

  *) mod_dav: When a PROPPATCH attempts to remove a non-existent dead
     property on a resource for which there is no dead property in the same
     namespace httpd segfaults. PR 52559 [Diego Santa Cruz
     <diego.santaCruz spinetix.com>]

  *) mod_dav: Sending an If or If-Match header with an invalid ETag doesn't
     result in a 412 Precondition Failed for a COPY operation. PR54610
     [Timothy Wood <tjw omnigroup.com>]

  *) mod_dav: Make sure that when we prepare an If URL for Etag comparison,
     we compare unencoded paths. PR 53910 [Timothy Wood <tjw omnigroup.com>]

  *) mod_deflate: Remove assumptions as to when an EOS bucket might arrive.
     Gracefully step aside if the body size is zero. [Graham Leggett]

  *) 'AuthGroupFile' and 'AuthUserFile' do not accept anymore the optional
     'standard' keyword . It was unused and not documented.
     PR54463 [Tianyin Xu <tixu cs.ucsd.edu> and Christophe Jaillet]

  *) core: Do not over allocate memory within 'ap_rgetline_core' for
     the common case. [Christophe Jaillet]

  *) core: speed up (for common cases) and reduce memory usage of
     ap_escape_logitem(). This should save 70-100 bytes in the request
     pool for a default config. [Christophe Jaillet]

  *) mod_dav: Ensure URI is correctly uriencoded on return. PR 54611
     [Timothy Wood <tjw omnigroup.com>]

  *) mod_proxy: Reject invalid values for Max-Forwards. [Graham Leggett,
     Co-Advisor <coad measurement-factory.com>]

  *) mod_cache: RFC2616 14.9.3 The s-maxage directive also implies the
     semantics of the proxy-revalidate directive. [Graham Leggett]

  *) mod_ssl: add support for subjectAltName-based host name checking
     in proxy mode (SSLProxyCheckPeerName). PR 54030. [Kaspar Brand]

  *) core: Use the proper macro for HTTP/1.1. [Graham Leggett]

  *) event MPM: Provide error handling for ThreadStackSize. PR 54311
     [Tianyin Xu <tixu cs.ucsd.edu>, Christophe Jaillet]

  *) mod_dav: Do not segfault on PROPFIND with a zero length DBM.
     PR 52559 [Diego Santa Cruz <diego.santaCruz spinetix.com>]

  *) core: Improve error message where client's request-line exceeds
     LimitRequestLine. PR 54384 [Christophe Jaillet]

  *) mod_macro: New module that provides macros within configuration files.
     [Fabien Coelho]

  *) mod_cache_socache: New cache implementation backed by mod_socache
     that replaces mod_mem_cache known from httpd 2.2. [Graham
     Leggett]

  *) htpasswd: Add -v option to verify a password. [Stefan Fritsch]

  *) mod_proxy: Add BalancerInherit and ProxyPassInherit to control
     whether Proxy Balancers and Workers are inherited by vhosts
     (default is On). [Jim Jagielski]

  *) mod_authnz_ldap: Allow using exec: calls to obtain LDAP bind
     password.  [Daniel Ruggeri]

  *) Added balancer parameter failontimeout to allow server admin
     to configure an IO timeout as an error in the balancer.
     [Daniel Ruggeri]

  *) mod_auth_digest: Fix crashes if shm initialization failed. [Stefan
     Fritsch]

  *) htpasswd, htdbm: Fix password generation. PR 54735. [Stefan Fritsch]

  *) core: Add workaround for gcc bug on sparc/64bit. PR 52900.
     [Stefan Fritsch]

  *) mod_setenvif: Fix crash in case SetEnvif and SetEnvIfExpr are used
     together. PR 54881. [Ruediger Pluem]

  *) htdigest: Fix buffer overflow when reading digest password file
     with very long lines. PR 54893. [Rainer Jung]

  *) ap_expr: Add the ability to base64 encode and base64 decode
     strings and to generate their SHA1 and MD5 hash.
     [Graham Leggett, Stefan Fritsch]

  *) mod_log_config: Fix crash when logging request end time for a failed
     request.  PR 54828 [Rainer Jung]

  *) mod_ssl: Catch missing, mismatched or encrypted client cert/key pairs
     with SSLProxyMachineCertificateFile/Path directives. PR 52212, PR 54698.
     [Keith Burdis <keith burdis.org>, Joe Orton, Kaspar Brand]

  *) mod_ssl: Quiet FIPS mode weak keys disabled and FIPS not selected emits
     in the error log to debug level.  [William Rowe]

  *) mod_cache_disk: CacheMinFileSize and CacheMaxFileSize were always
     using compiled in defaults of 1000000/1 respectively. [Eric Covener]

  *) mod_lbmethod_heartbeat, mod_heartmonitor: Respect DefaultRuntimeDir/
     DEFAULT_REL_RUNTIMEDIR for the heartbeat storage file.  [Jeff Trawick]

  *) mod_include: Use new ap_expr for 'elif', like 'if',
     if legacy parser is not specified.  PR 54548 [Tom Donovan]

  *) mod_lua: Add some new functions: r:htpassword(), r:mkdir(), r:mkrdir(),
     r:rmdir(), r:touch(), r:get_direntries(), r.date_parse_rfc().
     [Guenter Knauf]

  *) mod_lua: Add multipart form data handling. [Daniel Gruno]

  *) mod_lua: If a LuaMapHandler doesn't return any value, log a warning
     and treat it as apache2.OK. [Eric Covener]

  *) mod_lua: Add bindings for apr_dbd/mod_dbd database access
     [Daniel Gruno]

  *) mod_lua: Add LuaInputFilter/LuaOutputFilter for creating content
     filters in Lua [Daniel Gruno]

  *) mod_lua: Allow scripts handled by the lua-script handler to return
     a status code to the client (such as a 302 or a 500) [Daniel Gruno]

  *) mod_lua: Decline handling 'lua-script' if the file doesn't exist,
     rather than throwing an internal server error. [Daniel Gruno]

  *) mod_lua: Add functions r:flush and r:sendfile as well as additional
     request information to the request_rec structure. [Daniel Gruno]

  *) mod_lua: Add a server scope for Lua states, which creates a pool of
     states with manageable minimum and maximum size. [Daniel Gruno]

  *) mod_lua: Add new directive, LuaMapHandler, for dynamically mapping
     URIs to Lua scripts and functions using regular expressions.
     [Daniel Gruno]

  *) mod_lua: Add new directive LuaCodeCache for controlling in-memory
     caching of lua scripts. [Daniel Gruno]

Changes with Apache 2.4.4

  *) SECURITY: CVE-2012-3499 (cve.mitre.org)
     Various XSS flaws due to unescaped hostnames and URIs HTML output in
     mod_info, mod_status, mod_imagemap, mod_ldap, and mod_proxy_ftp.
     [Jim Jagielski, Stefan Fritsch, Niels Heinen <heinenn google com>]

  *) SECURITY: CVE-2012-4558 (cve.mitre.org)
     XSS in mod_proxy_balancer manager interface. [Jim Jagielski,
     Niels Heinen <heinenn google com>]

  *) mod_dir: Add support for the value 'disabled' in FallbackResource.
     [Vincent Deffontaines]

  *) mod_proxy_connect: Don't keepalive the connection to the client if the
     backend closes the connection. PR 54474. [Pavel Mateja <pavel netsafe cz>]

  *) mod_lua: Add bindings for mod_dbd/apr_dbd database access.
     [Daniel Gruno]

  *) mod_proxy: Allow for persistence of local changes made via the
     balancer-manager between graceful/normal restarts and power
     cycles. [Jim Jagielski]

  *) mod_proxy: Fix startup crash with mis-defined balancers.
     PR 52402. [Jim Jagielski]

  *) --with-module: Fix failure to integrate them into some existing
     module directories.  PR 40097.  [Jeff Trawick]

  *) htcacheclean: Fix potential segfault if "-p" is omitted.  [Joe Orton]

  *) mod_proxy_http: Honour special value 0 (unlimited) of LimitRequestBody
     PR 54435.  [Pavel Mateja <pavel netsafe.cz>]

  *) mod_proxy_ajp: Support unknown HTTP methods. PR 54416.
     [Rainer Jung]

  *) htcacheclean: Fix list options "-a" and "-A".
     [Rainer Jung]

  *) mod_slotmem_shm: Fix mistaken reset of num_free for restored shm.
     [Jim Jagielski]

  *) mod_proxy: non-existence of byrequests is not an immediate error.
     [Jim Jagielski]

  *) mod_proxy_balancer: Improve output of balancer-manager (re: Drn,
     Dis, Ign, Stby). PR 52478 [Danijel <dt-ng rbfh de>]

  *) configure: Fix processing of --disable-FEATURE for various features.
     [Jeff Trawick]

  *) mod_dialup/mod_http: Prevent a crash in mod_dialup in case of internal
     redirect. PR 52230.

  *) various modules, rotatelogs: Replace use of apr_file_write() with
     apr_file_write_full() to prevent incomplete writes. PR 53131.
     [Nicolas Viennot <apache viennot biz>, Stefan Fritsch]

  *) ab: Support socket timeout (-s timeout).
     [Guido Serra <zeph fsfe org>]

  *) httxt2dbm: Correct length computation for the 'value' stored in the
     DBM file. PR 47650 [jon buckybox com]

  *) core: Be more correct about rejecting directives that cannot work in <If>
     sections. [Stefan Fritsch]

  *) core: Fix directives like LogLevel that need to know if they are invoked
     at virtual host context or in Directory/Files/Location/If sections to
     work properly in If sections that are not in a Directory/Files/Location.
     [Stefan Fritsch]

  *) mod_xml2enc: Fix problems with charset conversion altering the
     Content-Length. [Micha Lenk <micha lenk info>]

  *) ap_expr: Add req_novary function that allows HTTP header lookups
     without adding the name to the Vary header. [Stefan Fritsch]

  *) mod_slotmem_*: Add in new fgrab() function which forces a grab and
     slot allocation on a specified slot. Allow for clearing of inuse
     array. [Jim Jagielski]

  *) mod_proxy_ftp: Fix segfaults on IPv4 requests to hosts with DNS
     AAAA records. PR  40841. [Andrew Rucker Jones <arjones simultan
     dyndns org>, <ast domdv de>, Jim Jagielski]

  *) mod_auth_form: Make sure that get_notes_auth() sets the user as does
     get_form_auth() and get_session_auth(). Makes sure that REMOTE_USER
     does not vanish during mod_include driven subrequests. [Graham
     Leggett]

  *) mod_cache_disk: Resolve errors while revalidating disk-cached files on
     Windows ("...rename tempfile to datafile failed..."). PR 38827
     [Eric Covener]

  *) mod_proxy_balancer: Bring XML output up to date. [Jim Jagielski]

  *) htpasswd, htdbm: Optionally read passwords from stdin, as more
     secure alternative to -b.  PR 40243. [Adomas Paltanavicius <adomas
     paltanavicius gmail com>, Stefan Fritsch]

  *) htpasswd, htdbm: Add support for bcrypt algorithm (requires
     apr-util 1.5 or higher). PR 49288. [Stefan Fritsch]

  *) htpasswd, htdbm: Put full 48bit of entropy into salt, improve
     error handling. Add some of htpasswd's improvements to htdbm,
     e.g. warn if password is truncated by crypt(). [Stefan Fritsch]

  *) mod_auth_form: Support the expr parser in the
     AuthFormLoginRequiredLocation, AuthFormLoginSuccessLocation and
     AuthFormLogoutLocation directives. [Graham Leggett]

  *) mod_ssl: Add support for TLS-SRP (Secure Remote Password key exchange
     for TLS, RFC 5054). PR 51075. [Quinn Slack <sqs cs stanford edu>,
     Christophe Renou, Peter Sylvester]

  *) mod_rewrite: Stop mergeing RewriteBase down to subdirectories
     unless new option 'RewriteOptions MergeBase' is configured.
     PR 53963. [Eric Covener]

  *) mod_header: Allow for exposure of loadavg and server load using new
     format specifiers %l, %i, %b [Jim Jagielski]

  *) core: Make ap_regcomp() return AP_REG_ESPACE if out of memory.  Make
     ap_pregcomp() abort if out of memory. This raises the minimum PCRE
     requirement to version 6.0. [Stefan Fritsch]

  *) mod_proxy: Add ability to configure the sticky session separator.
     PR 53893. [<inu inusasha de>, Jim Jagielski]

  *) mod_dumpio: Correctly log large messages
     PR 54179 [Marek Wianecki <mieszek2 interia pl>]

  *) core: Don't fail at startup with AH00554 when Include points to
     a directory without any wildcard character. [Eric Covener]

  *) core: Fail startup if the argument to ServerTokens is unrecognized.
     [Jackie Zhang  <jackie.qq.zhang gmail.com>]

  *) mod_log_forensic: Don't log a spurious "-" if a request has been rejected
     before mod_log_forensic could attach its id to it. [Stefan Fritsch]

  *) rotatelogs: Omit the second argument for the first invocation of
     a post-rotate program when -p is used, per the documentation.
     [Joe Orton]

  *) mod_session_dbd: fix a segmentation fault in the function dbd_remove.
     PR 53452. [<rebanerebane gmail com>, Reimo Rebane]

  *) core: Functions to provide server load values: ap_get_sload() and
     ap_get_loadavg(). [Jim Jagielski, Jan Kaluza <jkaluza redhat.com>,
     Jeff Trawick]

  *) mod_ldap: Fix regression in handling "server unavailable" errors on
     Windows.  PR 54140.  [Eric Covener]

  *) syslog logging: Remove stray ", referer" at the end of some messages.
     [Jeff Trawick]

  *) "Iterate" directives: Report an error if no arguments are provided.
     [Jeff Trawick]

  *) mod_ssl: Change default for SSLCompression to off, as compression
     causes security issues in most setups. (The so called "CRIME" attack).
     [Stefan Fritsch]

  *) ab: add TLS1.1/TLS1.2 options to -f switch, and adapt output
     to more accurately report the negotiated protocol. PR 53916.
     [Nicolás Pernas Maradei <nico emutex com>, Kaspar Brand]

  *) core: ErrorDocument now works for requests without a Host header.
     PR 48357.  [Jeff Trawick]

  *) prefork: Avoid logging harmless errors during graceful stop.
     [Joe Orton, Jeff Trawick]

  *) mod_proxy: When concatting for PPR, avoid cases where we
     concat ".../" and "/..." to create "...//..." [Jim Jagielski]

  *) mod_cache: Wrong content type and character set when
     mod_cache serves stale content because of a proxy error.
     PR 53539.  [Rainer Jung, Ruediger Pluem]

  *) mod_proxy_ajp: Fix crash in packet dump code when logging
     with LogLevel trace7 or trace8.  PR 53730.  [Rainer Jung]

  *) httpd.conf: Removed the configuration directives setting a bad_DNT
     environment introduced in 2.4.3. The actual directives are commented
     out in the default conf file.

  *) core: Apply length limit when logging Status header values.
     [Jeff Trawick, Chris Darroch]

  *) mod_proxy_balancer: The nonce is only derived from the UUID iff
     not set via the 'nonce' balancer param. [Jim Jagielski]

  *) mod_ssl: Match wildcard SSL certificate names in proxy mode.
     PR 53006.  [Joe Orton]

  *) Windows: Fix output of -M, -L, and similar command-line options
     which display information about the server configuration.
     [Jeff Trawick]

Changes with Apache 2.4.3

  *) SECURITY: CVE-2012-3502  (cve.mitre.org)
     mod_proxy_ajp, mod_proxy_http: Fix an issue in back end
     connection closing which could lead to privacy issues due
     to a response mixup. PR 53727. [Rainer Jung]

  *) SECURITY: CVE-2012-2687 (cve.mitre.org)
     mod_negotiation: Escape filenames in variant list to prevent a
     possible XSS for a site where untrusted users can upload files to
     a location with MultiViews enabled. [Niels Heinen <heinenn google.com>]

  *) mod_authnz_ldap: Don't try a potentially expensive nested groups
     search before exhausting all AuthLDAPGroupAttribute checks on the
     current group. PR 52464 [Eric Covener]

  *) mod_lua: Add new directive LuaAuthzProvider to allow implementing an
     authorization provider in lua. [Stefan Fritsch]

  *) core: Be less strict when checking whether Content-Type is set to
     "application/x-www-form-urlencoded" when parsing POST data,
     or we risk losing data with an appended charset. PR 53698
     [Petter Berntsen <petterb gmail.com>]

  *) httpd.conf: Added configuration directives to set a bad_DNT environment
     variable based on User-Agent and to remove the DNT header field from
     incoming requests when a match occurs. This currently has the effect of
     removing DNT from requests by MSIE 10.0 because it deliberately violates
     the current specification of DNT semantics for HTTP. [Roy T. Fielding]

  *) mod_socache_shmcb: Fix bus error due to a misalignment
     in some 32 bit builds, especially on Solaris Sparc.
     PR 53040.  [Rainer Jung]

  *) mod_cache: Set content type in case we return stale content.
     [Ruediger Pluem]

  *) Windows: Fix SSL failures on windows with AcceptFilter https none.
     PR 52476.  [Jeff Trawick]

  *) ab: Fix read failure when targeting SSL server.  [Jeff Trawick]

  *) The following now respect DefaultRuntimeDir/DEFAULT_REL_RUNTIMEDIR:
     - mod_auth_digest: shared memory file
     [Jeff Trawick]

  *) htpasswd: Use correct file mode for checking if file is writable.
     PR 45923. [Stefan Fritsch]

  *) mod_rewrite: Fix crash with dbd RewriteMaps. PR 53663. [Mikhail T.
     <mi apache aldan algebra com>]

  *) mod_ssl: Add new directive SSLCompression to disable TLS-level
     compression. PR 53219. [Björn Jacke <bjoern j3e de>, Stefan Fritsch]

  *) mod_lua: Add a few missing request_rec fields. Rename remote_ip to
     client_ip to match conn_rec. [Stefan Fritsch]

  *) mod_lua: Change prototype of vm_construct, to work around gcc bug which
     causes a segfault. PR 52779. [Dick Snippe <Dick Snippe tech omroep nl>]

  *) mpm_event: Don't count connections in lingering close state when
     calculating how many additional connections may be accepted.
     [Stefan Fritsch]

  *) mod_ssl: If exiting during initialization because of a fatal error,
     log a message to the main error log pointing to the appropriate
     virtual host error log. [Stefan Fritsch]

  *) mod_proxy_ajp: Reduce memory usage in case of many keep-alive requests on
     one connection. PR 52275. [Naohiro Ooiwa <naohiro ooiwa miraclelinux com>]

  *) mod_proxy_balancer: Restore balancing after a failed worker has
     recovered when using lbmethod_bybusyness.  PR 48735.  [Jeff Trawick]

  *) mod_setenvif: Compile some global regex only once during startup.
     This should save some memory, especially with .htaccess.
     [Stefan Fritsch]

  *) core: Add the port number to the vhost's name in the scoreboard.
     [Stefan Fritsch]

  *) mod_proxy: Fix ProxyPassReverse for balancer configurations.
     PR 45434.  [Joe Orton]

  *) mod_lua: Add the parsebody function for parsing POST data. PR 53064.
     [Daniel Gruno]

  *) apxs: Use LDFLAGS from config_vars.mk in addition to CFLAGS and CPPFLAGS.
     [Stefan Fritsch]

  *) mod_proxy: Fix memory leak or possible corruption in ProxyBlock
     implementation.  [Ruediger Pluem, Joe Orton]

  *) mod_proxy: Check hostname from request URI against ProxyBlock list,
     not forward proxy, if ProxyRemote* is configured.  [Joe Orton]

  *) mod_proxy_connect: Avoid DNS lookup on hostname from request URI
     if ProxyRemote* is configured.  PR 43697.  [Joe Orton]

  *) mpm_event, mpm_worker: Remain active amidst prevalent child process
     resource shortages.  [Jeff Trawick]

  *) Add "strict" and "warnings" pragmas to Perl scripts.  [Rich Bowen]

  *) The following now respect DefaultRuntimeDir/DEFAULT_REL_RUNTIMEDIR:
     - core: the scoreboard (ScoreBoardFile), pid file (PidFile), and
       mutexes (Mutex)
     [Jim Jagielski]

  *) ab: Fix bind() errors.  [Joe Orton]

  *) mpm_event: Don't do a blocking write when starting a lingering close
     from the listener thread. PR 52229. [Stefan Fritsch]

  *) mod_so: If a filename without slashes is specified for LoadFile or
     LoadModule and the file cannot be found in the server root directory,
     try to use the standard dlopen() search path. [Stefan Fritsch]

  *) mpm_event, mpm_worker: Fix cases where the spawn rate wasn't reduced
     after child process resource shortages.  [Jeff Trawick]

  *) mpm_prefork: Reduce spawn rate after a child process exits due to
     unexpected poll or accept failure.  [Jeff Trawick]

  *) core: Log value of Status header line in script responses rather
     than the fixed header name.  [Chris Darroch]

  *) mod_ssl: Fix handling of empty response from OCSP server.
     [Jim Meyering <meyering redhat.com>, Joe Orton]

  *) mpm_event: Fix handling of MaxConnectionsPerChild. [Stefan Fritsch]

  *) mod_authz_core: If an expression in "Require expr" returns denied and
     references %{REMOTE_USER}, trigger authentication and retry. PR 52892.
     [Stefan Fritsch]

  *) core: Always log if LimitRequestFieldSize triggers.  [Stefan Fritsch]

  *) mod_deflate: Skip compression if compression is enabled at SSL level.
     [Stefan Fritsch]

  *) core: Add missing HTTP status codes registered with IANA.
     [Julian Reschke <julian.reschke gmx.de>, Rainer Jung]

  *) mod_ldap: Treat the "server unavailable" condition as a transient
     error with all LDAP SDKs.  [Filip Valder <filip.valder vsb.cz>]

  *) core: Fix spurious "not allowed here" error returned when the Options
     directive is used in .htaccess and "AllowOverride Options" (with no
     specific options restricted) is configured.  PR 53444. [Eric Covener]

  *) mod_authz_core: Fix parsing of Require arguments in <AuthzProviderAlias>.
     PR 53048. [Stefan Fritsch]

  *) mod_log_config: Fix %{abc}C truncating cookie values at first "=".
     PR 53104. [Greg Ames]

  *) mod_ext_filter: Fix error_log spam when input filters are configured.
     [Joe Orton]

  *) mod_rewrite: Add "AllowAnyURI" option. PR 52774. [Joe Orton]

  *) htdbm, htpasswd: Don't crash if crypt() fails (e.g. with FIPS enabled).
     [Paul Wouters <pwouters redhat.com>, Joe Orton]

  *) core: Use a TLS 1.0 close_notify alert for internal dummy connection if
     the chosen listener is configured for https. [Joe Orton]

  *) mod_proxy: Use the the same hostname for SNI as for the HTTP request when
     forwarding to SSL backends. PR 53134.
     [Michael Weiser <michael weiser.dinsnail.net>, Ruediger Pluem]

  *) mod_info: Display all registered providers. [Stefan Fritsch]

  *) mod_ssl: Send the error message for speaking http to an https port using
     HTTP/1.0 instead of HTTP/0.9, and omit the link that may be wrong when
     using SNI. PR 50823. [Stefan Fritsch]

  *) core: Fix segfault in logging if r->useragent_addr or c->client_addr is
     unset. PR 53265. [Stefan Fritsch]

  *) log_server_status: Bring Perl style forward to the present, use
     standard modules, update for new format of server-status output.
     PR 45424. [Richard Bowen, Dave Brondsema, and others]

  *) mod_sed, mod_log_debug, mod_rewrite: Symbol namespace cleanups.
     [Joe Orton, André Malo]

  *) core: Prevent "httpd -k restart" from killing server in presence of
     config error. [Joe Orton]

  *) mod_proxy_fcgi: If there is an error reading the headers from the
     backend, send an error to the client. PR 52879. [Stefan Fritsch]

Changes with Apache 2.4.2

  *) SECURITY: CVE-2012-0883 (cve.mitre.org)
     envvars: Fix insecure handling of LD_LIBRARY_PATH that could lead to the
     current working directory to be searched for DSOs. [Stefan Fritsch]

  *) mod_slotmem_shm: Honor DefaultRuntimeDir [Jim Jagielski]

  *) mod_ssl: Fix crash with threaded MPMs due to race condition when
     initializing EC temporary keys. [Stefan Fritsch]

  *) mod_rewrite: Fix RewriteCond integer checks to be parsed correctly.
     PR 53023. [Axel Reinhold <apache freakout.de>, André Malo]

  *) mod_proxy: Add the forcerecovery balancer parameter that determines if
     recovery for balancer workers is enforced. [Ruediger Pluem]

  *) Fix MPM DSO load failure on AIX.  [Jeff Trawick]

  *) mod_proxy: Correctly set up reverse proxy worker. PR 52935.
     [Petter Berntsen <petterb gmail.com>]

  *) mod_sed: Don't define PATH_MAX to a potentially undefined value, causing
     compile problems on GNU hurd. [Stefan Fritsch]

  *) core: Add ap_runtime_dir_relative() and DefaultRuntimeDir.
     [Jeff Trawick]

  *) core: Fix breakage of Listen directives with MPMs that use a
     per-directory config. PR 52904. [Stefan Fritsch]

  *) core: Disallow directives in AllowOverrideList which are only allowed
     in VirtualHost or server context. These are usually not prepared to be
     called in .htaccess files. [Stefan Fritsch]

  *) core: In AllowOverrideList, do not allow 'None' together with other
     directives. PR 52823. [Stefan Fritsch]

  *) mod_slotmem_shm: Support DEFAULT_REL_RUNTIMEDIR for file-based shm.
     [Jim Jagielski]

  *) core: Fix merging of AllowOverrideList and ContentDigest.
     [Stefan Fritsch]

  *) mod_request: Fix validation of the KeptBodySize argument so it
     doesn't always throw a configuration error. PR 52981 [Eric Covener]

  *) core: Add filesystem paths to access denied / access failed messages
     AH00035 and AH00036. [Eric Covener]

  *) mod_dumpio: Properly handle errors from subsequent input filters.
     PR 52914. [Stefan Fritsch]

  *) Unix MPMs: Fix small memory leak in parent process if connect()
     failed when waking up children.  [Joe Orton]

  *) "DirectoryIndex disabled" now undoes DirectoryIndex settings in
     the current configuration section, not just previous config sections.
     PR 52845. [Eric Covener]

  *) mod_xml2enc: Fix broken handling of EOS buckets which could lead to
     response headers not being sent. PR 52766. [Stefan Fritsch]

  *) mod_ssl: Properly free the GENERAL_NAMEs. PR 32652. [Kaspar Brand]

  *) core: Check during config test that directories for the access
     logs actually exist. PR 29941. [Stefan Fritsch]

  *) mod_xml2enc, mod_proxy_html: Enable per-module loglevels.
     [Stefan Fritsch]

  *) mod_filter: Fix segfault with AddOutputFilterByType. PR 52755.
     [Stefan Fritsch]

  *) mod_session: Sessions are encoded as application/x-www-form-urlencoded
     strings, however we do not handle the encoding of spaces properly.
     Fixed. [Graham Leggett]

  *) Configuration: Example in comment should use a path consistent
     with the default configuration. PR 52715.
     [Rich Bowen, Jens Schleusener, Rainer Jung]

  *) Configuration: Switch documentation links from trunk to 2.4.
     [Rainer Jung]

  *) configure: Fix out of tree build using apr and apr-util in srclib.
     [Rainer Jung]

Changes with Apache 2.4.1

  *) SECURITY: CVE-2012-0053 (cve.mitre.org)
     Fix an issue in error responses that could expose "httpOnly" cookies
     when no custom ErrorDocument is specified for status code 400.
     [Eric Covener]

  *) mod_proxy_balancer: Fix crash on Windows. PR 52402 [Mladen Turk]

  *) core: Check during configtest that the directories for error logs exist.
     PR 29941 [Stefan Fritsch]

  *) Core configuration: add AllowOverride option to treat syntax
     errors in .htaccess as non-fatal. PR 52439 [Nick Kew, Jim Jagielski]

  *) core: Fix memory consumption in core output filter with streaming
     bucket types like CGI or PIPE.  [Joe Orton, Stefan Fritsch]

  *) configure: Disable modules at configure time if a prerequisite module
     is not enabled. PR 52487. [Stefan Fritsch]

  *) Rewrite and proxy now decline what they don't support rather
     than fail the request. [Joe Orton]

  *) Fix building against external apr plus apr-util if apr is not installed
     in a system default path. [Rainer Jung]

  *) Doxygen fixes and improvements. [Joe Orton, Igor Galić]

  *) core: Fix building against PCRE 8.30 by switching from the obsolete
     pcre_info() to pcre_fullinfo(). PR 52623 [Ruediger Pluem, Rainer Jung]

Changes with Apache 2.4.0

  *) SECURITY: CVE-2012-0031 (cve.mitre.org)
     Fix scoreboard issue which could allow an unprivileged child process
     to cause the parent to crash at shutdown rather than terminate
     cleanly.  [Joe Orton]

  *) mod_ssl: Fix compilation with xlc on AIX. PR 52394. [Stefan Fritsch]

  *) SECURITY: CVE-2012-0021 (cve.mitre.org)
     mod_log_config: Fix segfault (crash) when the '%{cookiename}C' log format
     string is in use and a client sends a nameless, valueless cookie, causing
     a denial of service. The issue existed since version 2.2.17 and 2.3.3.
     PR 52256.  [Rainer Canavan <rainer-apache 7val com>]

  *) mod_ssl: when compiled against OpenSSL 1.0.1 or later, allow explicit
     control of TLSv1.1 and TLSv1.2 through the SSLProtocol directive.
     [Kaspar Brand]

  *) mod_ssl: set OPENSSL_NO_SSL_INTERN when compiling against OpenSSL 1.0.1
     or later, to improve binary compatibility with future OpenSSL releases.
     [Kaspar Brand]

  *) mod_mime: Don't arbitrarily bypass AddOutputFilter during a ProxyPass,
     but then allow AddOutputFilter during a RewriteRule [P]. Make mod_mime
     behave identically in both cases. PR52342. [Graham Leggett]

  *) Move ab, logresolve, httxt2dbm and apxs to bin from sbin, along with
     corresponding man pages. [Graham Leggett]

  *) Distinguish properly between the bindir and sbindir directories when
     installing binaries. Previously all binaries were silently installed to
     sbindir, whether they were system administration commands or not.
     [Graham Leggett]

Changes with Apache 2.3.16

  *) SECURITY: CVE-2011-4317 (cve.mitre.org)
     Resolve additional cases of URL rewriting with ProxyPassMatch or
     RewriteRule, where particular request-URIs could result in undesired
     backend network exposure in some configurations.
     [Joe Orton]

  *) core: Limit line length in .htaccess to 8K like in 2.2.x, to avoid
     additional DoS potential. [Stefan Fritsch]

  *) core, all modules: Add unique tag to most error log messages. [Stefan
     Fritsch]

  *) mod_socache_memcache: Change provider name from "mc" to "memcache" to
     match module name. [Stefan Fritsch]

  *) mod_slotmem_shm: Change provider name from "shared" to "shm" to match
     module name. [Stefan Fritsch]

  *) mod_ldap: Fix segfault with Solaris LDAP when enabling ldaps. This
     requires an apr-util fix in which is available in apr-util >= 1.4.0.
     PR 42682. [Stefan Fritsch]

  *) mod_rewrite: Add the AllowNoSlash RewriteOption, which makes it possible
     for RewriteRules to be placed in .htaccess files that match the directory
     with no trailing slash. PR 48304.
     [Matthew Byng-Maddick <matthew byng-maddick bbc.co.uk>]

  *) mod_session_crypto: Add a SessionCryptoPassphraseFile directive so that
     the administrator can hide the keys from the configuration. [Graham
     Leggett]

  *) Introduce a per request version of the remote IP address, which can be
     optionally modified by a module when the effective IP of the client
     is not the same as the real IP of the client (such as a load balancer).
     Introduce a per connection "peer_ip" and a per request "client_ip" to
     distinguish between the raw IP address of the connection and the effective
     IP address of the request. [Graham Leggett]

  *) ap_pass_brigade_fchk() function added. [Jim Jagielski]

  *) core: Pass ap_errorlog_info struct to error log hook. [Stefan Fritsch]

  *) mod_cache_disk: Make sure we check return codes on all writes and
     attempts to close, and clean up after ourselves in these cases.
     PR43589. [Graham Leggett]

  *) mod_cache_disk: Remove the unnecessary intermediate brigade while
     writing to disk. Fixes a problem where mod_disk_cache was leaving
     buckets in the intermediate brigade and not passing them to out on
     exit. [Florian S. <f_los_ch yahoo.com>, Graham Leggett]

  *) mod_ssl: use a shorter setting for SSLCipherSuite in the default
     default configuration file, and add some more information about
     configuring a speed-optimized alternative.
     [Kaspar Brand]

  *) mod_ssl: drop support for the SSLv2 protocol. [Kaspar Brand]

  *) mod_lua: Stop losing track of all but the most specific LuaHook* directives
     when multiple per-directory config sections are used.  Adds LuaInherit
     directive to control how parent sections are merged.  [Eric Covener]

  *) Server directive display (-L): Include directives of DSOs.
     [Jeff Trawick]

  *) mod_cache: Make sure we merge headers correctly when we handle a
     non cacheable conditional response. PR52120. [Graham Leggett]

  *) Pre GA removal of components that will not be included:
     - mod_noloris was superseded by mod_reqtimeout
     - mod_serf
     - mpm_simple
     [Rainer Jung]

  *) core: Set MaxMemFree 2048 by default. [Stefan Fritsch]

  *) mpm_event: Fix assertion failure during very high load. [Stefan Fritsch]

  *) configure: Additional modules loaded by default: mod_headers.
     Modules moved from module set "few" to "most" and no longer loaded
     by default: mod_actions, mod_allowmethods, mod_auth_form, mod_buffer,
     mod_cgi(d), mod_include, mod_negotiation, mod_ratelimit, mod_request,
     mod_userdir. [Rainer Jung]

  *) mod_lua: Use the right lua scope when used as a hook. [Rainer Jung]

  *) configure: Only load the really imporant modules (i.e. those enabled by
     the 'few' selection) by default. Don't handle modules enabled with
     --enable-foo specially. [Stefan Fritsch]

  *) end-generation hook: Fix false notification of end-of-generation for
     temporary intervals with no active MPM children.  [Jeff Trawick]

  *) mod_ssl: Add support for configuring persistent TLS session ticket
     encryption/decryption keys (useful for clustered environments).
     [Paul Querna, Kaspar Brand]

  *) mod_usertrack: Use random value instead of remote IP address.
     [Stefan Fritsch]

Changes with Apache 2.3.15

  *) SECURITY: CVE-2011-3348 (cve.mitre.org)
     mod_proxy_ajp: Respond with HTTP_NOT_IMPLEMENTED when the method is not
     recognized.  [Jean-Frederic Clere]

  *) SECURITY: CVE-2011-3192 (cve.mitre.org)
     core: Fix handling of byte-range requests to use less memory, to avoid
     denial of service. If the sum of all ranges in a request is larger than
     the original file, ignore the ranges and send the complete file.
     PR 51714. [Stefan Fritsch, Jim Jagielski, Ruediger Pluem, Eric Covener,
     <lowprio20 gmail.com>]

  *) SECURITY: CVE-2011-3607 (cve.mitre.org)
     core: Fix integer overflow in ap_pregsub. This can be triggered e.g.
     with mod_setenvif via a malicious .htaccess. [Stefan Fritsch]

  *) SECURITY: CVE-2011-3368 (cve.mitre.org)
     Reject requests where the request-URI does not match the HTTP
     specification, preventing unexpected expansion of target URLs in
     some reverse proxy configurations.  [Joe Orton]

  *) configure: Load all modules in the generated default configuration
     when using --enable-load-all-modules. [Rainer Jung]

  *) mod_reqtimeout: Change the default to set some reasonable timeout
     values. [Stefan Fritsch]

  *) core, mod_dav_fs: Change default ETag to be "size mtime", i.e. remove
     the inode. PR 49623. [Stefan Fritsch]

  *) mod_lua: Expose SSL variables via r:ssl_var_lookup().  [Eric Covener]

  *) mod_lua: LuaHook{AccessChecker,AuthChecker,CheckUserID,TranslateName}
     can now additionally be run as "early" or "late" relative to other modules.
     [Eric Covener]

  *) configure: By default, only load those modules that are either required
     or explicitly selected by a configure --enable-foo argument. The
     LoadModule statements for modules enabled by --enable-mods-shared=most
     and friends will be commented out. [Stefan Fritsch]

  *) mod_lua: Prevent early Lua hooks (LuaHookTranslateName and
     LuaHookQuickHandler) from being configured in <Directory>, <Files>,
     and htaccess where the configuration would have been ignored.
     [Eric Covener]

  *) mod_lua: Resolve "attempt to index local 'r' (a userdata value)" errors
     in LuaMapHandler scripts [Eric Covener]

  *) mod_log_debug: Rename optional argument from if= to expr=, to be more
     in line with other config directives. [Stefan Fritsch]

  *) mod_headers: Require an expression to be specified with expr=, to be more
     in line with other config directives. [Stefan Fritsch]

  *) mod_substitute: To prevent overboarding memory usage, limit line length
     to 1MB. [Stefan Fritsch]

  *) mod_lua: Make the query string (r.args) writable. [Eric Covener]

  *) mod_include: Add support for application/x-www-form-urlencoded encoding
     and decoding. [Graham Leggett]

  *) rotatelogs: Add -c option to force logfile creation in every rotation
     interval, even if empty.  [Jan Kaluža <jkaluza redhat.com>]

  *) core: Limit ap_pregsub() to 64K, add ap_pregsub_ex() for longer strings.
     [Stefan Fritsch]

  *) mod_session_crypto: Refactor to support the new apr_crypto API.
     [Graham Leggett]

  *) http: Add missing Location header if local URL-path is used as
     ErrorDocument for 30x. [Stefan Fritsch]

  *) mod_buffer: Make sure we step down for subrequests, but not for internal
     redirects triggered by mod_rewrite. [Graham Leggett]

  *) mod_lua: add r:construct_url as a wrapper for ap_construct_url.
     [Eric Covener]

  *) mod_remote_ip: Fix configuration of internal proxies. PR 49272.
     [Jim Riggs <jim riggs me>]

  *) mpm_winnt: Handle AcceptFilter 'none' mode correctly; resolve specific
     server IP endpoint and remote client IP upon connection.  [William Rowe]

  *) mod_setenvif: Remove OID match which is obsoleted by SetEnvIfExpr with
     PeerExtList(). [Stefan Fritsch]

  *) mpm_prefork, mpm_worker, mpm_event: If a child is created just before
     graceful restart and then exits because of a missing lock file, don't
     shutdown the whole server. PR 39311. [Shawn Michael
     <smichael rightnow com>]

  *) mpm_event: Check the return value from ap_run_create_connection.
     PR 41194. [Davi Arnaut]

  *) mod_mime_magic: Add signatures for PNG and SWF to the example config.
     PR 48352. [Jeremy Wagner-Kaiser <jwagner-kaiser adknowledge com>]

  *) core, unixd: Add -D DUMP_RUN_CFG option to dump some configuration items
     from the parsed (or default) config. This is useful for init scripts that
     need to setup temporary directories and permissions. [Stefan Fritsch]

  *) core, mod_actions, mod_asis: Downgrade error log messages which accompany
     a 404 request status from loglevel error to info. PR 35768. [Stefan
     Fritsch]

  *) core: Fix hook sorting with Perl modules. PR 45076. [Torsten Foertsch
     <torsten foertsch gmx net>]

  *) core: Enforce LimitRequestFieldSize after multiple headers with the same
     name have been merged. [Stefan Fritsch]

  *) mod_ssl: If MaxMemFree is set, ask OpenSSL >= 1.0.0 to reduce memory
     usage.  PR 51618. [Cristian Rodríguez <crrodriguez opensuse org>,
     Stefan Fritsch]

  *) mod_ssl: At startup, when checking a server certificate whether it
     matches the configured ServerName, also take dNSName entries in the
     subjectAltName extension into account. PR 32652, PR 47051. [Kaspar Brand]

  *) mod_substitute: Reduce memory usage and copying of data. PR 50559.
     [Stefan Fritsch]

  *) mod_ssl/proxy: enable the SNI extension for backend TLS connections
     [Kaspar Brand]

  *) Add wrappers for malloc, calloc, realloc that check for out of memory
     situations and use them in many places. PR 51568, PR 51569, PR 51571.
     [Stefan Fritsch]

  *) Fix cross-compilation of mod_cgi/mod_cgid when APR_HAVE_STRUCT_RLIMIT is
     false but RLIMIT_* are defined.  PR51371. [Eric Covener]

  *) core: Correctly obey ServerName / ServerAlias if the Host header from the
     request matches the VirtualHost address.
     PR 51709. [Micha Lenk <micha lenk.info>]

  *) mod_unique_id: Use random number generator to initialize counter.
     PR 45110. [Stefan Fritsch]

  *) core: Add convenience API for apr_random. [Stefan Fritsch]

  *) core: Add MaxRangeOverlaps and MaxRangeReversals directives to control
     the number of overlapping and reversing ranges (respectively) permitted
     before returning the entire resource, with a default limit of 20.
     [Jim Jagielski]

  *) mod_ldap: Optional function uldap_ssl_supported(r) always returned false
     if called from a virtual host with mod_ldap directives in it.  Did not
     affect mod_authnz_ldap's usage of mod_ldap.  [Eric Covener]

  *) mod_filter: Instead of dropping the Accept-Ranges header when a filter
     registered with AP_FILTER_PROTO_NO_BYTERANGE is present,
     set the header value to "none". [Eric Covener, Ruediger Pluem]

  *) core: Allow MaxRanges none|unlimited|default and set 'Accept-Ranges: none'
     in the case Ranges are being ignored with MaxRanges none.
     [Eric Covener]

  *) mod_ssl: revamp CRL-based revocation checking when validating
     certificates of clients or proxied servers. Completely delegate
     CRL processing to OpenSSL, and add a new [Proxy]CARevocationCheck
     directive for controlling the revocation checking mode. [Kaspar Brand]

  *) core: Add MaxRanges directive to control the number of ranges permitted
     before returning the entire resource, with a default limit of 200.
     [Eric Covener]

  *) mod_cache: Ensure that CacheDisable can correctly appear within
     a LocationMatch. [Graham Leggett]

  *) mod_cache: Fix the moving of the CACHE filter, which erroneously
     stood down if the original filter was not added by configuration.
     [Graham Leggett]

  *) mod_ssl: improve certificate error logging. PR 47408. [Kaspar Brand]

  *) mod_authz_groupfile: Increase length limit of lines in the group file to
     16MB. PR 43084. [Stefan Fritsch]

  *) core: Increase length limit of lines in the configuration file to 16MB.
     PR 45888. PR 50824. [Stefan Fritsch]

  *) core: Add API for resizable buffers. [Stefan Fritsch]

  *) mod_ldap: Enable LDAPConnectionTimeout for LDAP toolkits that have
     LDAP_OPT_CONNECT_TIMEOUT instead of LDAP_OPT_NETWORK_TIMEOUT, such
     as Tivoli Directory Server 6.3 and later. [Eric Covener]

  *) mod_ldap: Change default number of retries from 10 to 3, and add
     an LDAPRetries and LDAPRetryDelay directives. [Eric Covener]

  *) mod_authnz_ldap: Don't retry during authentication, because this just
     multiplies the ample retries already being done by mod_ldap. [Eric Covener]

  *) configure: Allow to explicitly disable modules even with module selection
     'reallyall'. [Stefan Fritsch]

  *) mod_rewrite: Check validity of each internal (int:) RewriteMap even if the
     RewriteEngine is disabled in server context, avoiding a crash while
     referencing the invalid int: map at runtime. PR 50994.
     [Ben Noordhuis <info noordhuis nl>]

  *) mod_ssl, configure: require OpenSSL 0.9.7 or later. [Kaspar Brand]

  *) mod_ssl: remove ssl_toolkit_compat layer. [Kaspar Brand]

  *) mod_ssl, configure, ab: drop support for RSA BSAFE SSL-C toolkit.
     [Kaspar Brand]

  *) mod_usertrack: Run mod_usertrack earlier in the fixups hook to ensure the
     cookie is set when modules such as mod_rewrite trigger a redirect. Also
     use r->err_headers_out for the cookie, for the same reason.  PR29755.
     [Sami J. Mäkinen <sjm almamedia fi>, Eric Covener]

  *) mod_proxy_http, mod_proxy_connect: Add 'proxy-status' and
     'proxy-source-port' request notes for logging. PR 30195. [Stefan Fritsch]

  *) configure: Enable ldap modules in 'all' and 'most' selections if ldap
     is compiled into apr-util. [Stefan Fritsch]

  *) core: Add ap_check_cmd_context()-check if a command is executed in
     .htaccess file. [Stefan Fritsch]

  *) mod_deflate: Fix endless loop if first bucket is metadata. PR 51590.
     [Torsten Foertsch <torsten foertsch gmx net>]

  *) mod_authn_socache: Fix to work in .htaccess if not configured anywhere
     in httpd.conf, and introduce an AuthnCacheEnable directive.
     PR 51991 [Nick Kew]

  *) mod_xml2enc: new (formerly third-party) module supporting
     internationalisation for filters via smart charset sniffing
     and conversion. [Nick Kew]

  *) mod_proxy_html: new (formerly third-party) module to fix up
     HTML links in a reverse proxy situation, where a backend
     generates URLs that are not resolvable by Clients. [Nick Kew]

Changes with Apache 2.3.14

  *) mod_proxy_ajp: Improve trace logging.  [Rainer Jung]

  *) mod_proxy_ajp: Respect "reuse" flag in END_REPONSE packets.
     [Rainer Jung]

  *) mod_proxy: enable absolute URLs to be rewritten with ProxyPassReverse,
     e.g. to reverse proxy "Location: https://other-internal-server/login"
     [Nick Kew]

  *) prefork, worker, event: Make sure crashes are logged to the error log if
     httpd has already detached from the console. [Stefan Fritsch]

  *) prefork, worker, event: Reduce period during startup/restart where a
     successive signal may be lost. PR 43696. [Arun Bhalla <arun shme net>]

  *) mod_allowmethods: Correct Merging of "reset" and do not allow an
     empty parameter list for the AllowMethods directive. [Rainer Jung]

  *) configure: Update selection of modules for 'all' and 'most'. 'all' will
     now enable all modules except for example and test modules. Make the
     selection for 'most' more useful (including ssl and proxy). Both 'all'
     and 'most' will now disable modules if dependencies are missing instead
     of aborting. If a specific module is requested with --enable-XXX=yes,
     missing dependencies will still cause configure to exit with an error.
     [Stefan Fritsch]

  *) mod_ldap: Revert the integration of apr-ldap as ap_ldap which was done
     in 2.3.13. [Stefan Fritsch]

  *) core: For '*' or '_default_' vhosts, use a wildcard address of any
     address family, rather than IPv4 only.  [Joe Orton]

  *) core, mod_rewrite, mod_ssl, mod_nw_ssl: Make the SERVER_NAME variable
     include [ ] for literal IPv6 addresses, as mandated by RFC 3875.
     PR 26005. [Stefan Fritsch]

  *) mod_negotiation: Fix parsing of Content-Length in type maps. PR 42203.
     [Nagae Hidetake <nagae eagan jp>]

  *) core: Add more logging to ap_scan_script_header_err* functions. Add
     ap_scan_script_header_err*_ex functions that take a module index for
     logging.
     mod_cgi, mod_cgid, mod_proxy_fcgi, mod_proxy_scgi, mod_isapi: Use the
     new functions in order to make logging configurable per-module.
     [Stefan Fritsch]

  *) mod_dir: Add DirectoryIndexRedirect to send an external redirect to
     the proper index.  [Eric Covener]

  *) mod_deflate: Don't try to compress requests with a zero sized body.
     PR 51350. [Stefan Fritsch]

  *) core: Fix startup on IPv6-only systems. PR 50592. [Joe Orton,
     <root linkage white-void net>]

  *) suexec: Add environment variables CONTEXT_DOCUMENT_ROOT, CONTEXT_PREFIX,
     REDIRECT_ERROR_NOTES, REDIRECT_SCRIPT_FILENAME, REQUEST_SCHEME to the
     whitelist in suexec. PR 51499. [Graham Laverty <graham reg ca>,
     Stefan Fritsch]

  *) mod_rewrite: Fix regexp RewriteCond with NoCase. [Stefan Fritsch]

  *) mod_log_debug: New module that allows to log custom messages at various
     phases in the request processing. [Stefan Fritsch]

  *) mod_ssl: Add some debug logging when loading server certificates.
     PR 37912. [Nick Burch <nick burch alfresco com>]

  *) configure: Support reallyall option also for --enable-mods-static.
     [Rainer Jung]

  *) mod_socache_dc: add --with-distcache to configure for choosing
     the distcache installation directory. [Rainer Jung]

  *) mod_socache_dc: use correct build variable MOD_SOCACHE_DC_LDADD
     instead of MOD_SOCACHE_LDADD in build macro. [Rainer Jung]

  *) mod_lua, mod_deflate: respect platform specific runpath linker
     flag. [Rainer Jung]

  *) configure: Only link the httpd binary against PCRE. No other support
     binary needs PCRE. [Rainer Jung]

  *) configure: tolerate dependency checking failures for modules if
     they have been enabled implicitly. [Rainer Jung]

  *) configure: Allow to specify module specific custom linker flags via
     the MOD_XXX_LDADD variables. [Rainer Jung]

Changes with Apache 2.3.13

  *) ab: Support specifying the local address to use. PR 48930.
     [Peter Schuller <scode spotify com>]

  *) core: Add support to ErrorLogFormat for logging the system unique
     thread id under Linux. [Stefan Fritsch]

  *) event: New AsyncRequestWorkerFactor directive to influence how many
     connections will be accepted per process. [Stefan Fritsch]

  *) prefork, worker, event: Rename MaxClients to MaxRequestWorkers which
     describes more accurately what it does. [Stefan Fritsch]

  *) rotatelogs: Add -p argument to specify custom program to invoke
     after a log rotation.  PR 51285. [Sven Ulland <sveniu ifi.uio.no>,
     Joe Orton]

  *) mod_ssl: Don't do OCSP checks for valid self-issued certs. [Kaspar Brand]

  *) mod_ssl: Avoid unnecessary renegotiations with SSLVerifyDepth 0.
     PR 48215. [Kaspar Brand]

  *) mod_status: Display information about asynchronous connections in the
     server-status. PR 44377. [Stefan Fritsch]

  *) mpm_event: If the number of connections of a process is very high, or if
     all workers are busy, don't accept new connections in that process.
     [Stefan Fritsch]

  *) mpm_event: Process lingering close asynchronously instead of tying up
     worker threads. [Jeff Trawick, Stefan Fritsch]

  *) mpm_event: If MaxMemFree is set, limit the number of pools that is kept
     around. [Stefan Fritsch]

  *) mpm_event: Fix graceful restart aborting connections. PR 43359.
     [Takashi Sato <takashi lans-tv com>]

  *) mod_ssl: Disable AECDH ciphers in example config. PR 51363.
     [Rob Stradling <rob comodo com>]

  *) core: Introduce new function ap_get_conn_socket() to access the socket of
     a connection. [Stefan Fritsch]

  *) mod_data: Introduce a filter to support RFC2397 data URLs. [Graham
     Leggett]

  *) mod_userdir/mod_alias/mod_vhost_alias: Correctly set DOCUMENT_ROOT,
     CONTEXT_DOCUMENT_ROOT, CONTEXT_PREFIX. PR 26052. PR 46198.
     [Stefan Fritsch]

  *) core: Allow to override document_root on a per-request basis. Introduce
     new context_document_root and context_prefix which provide information
     about non-global URI-to-directory mappings (from e.g. mod_userdir or
     mod_alias) to scripts. PR 49705. [Stefan Fritsch]

  *) core: Add <ElseIf> and <Else> to complement <If> sections.
     [Stefan Fritsch]

  *) mod_ext_filter: Remove DebugLevel option in favor of per-module loglevel.
     [Stefan Fritsch]

  *) mod_include: Make the "#if expr" element use the new "ap_expr" expression
     parser. The old parser can still be used by setting the new directive
     SSILegacyExprParser. [Stefan Fritsch]

  *) core: Add some features to ap_expr for use by mod_include: a restricted
     mode that does not allow to bypass request access restrictions; new
     variables DOCUMENT_URI (alias for REQUEST_URI), LAST_MODIFIED; -A as an
     alias for -U; an additional data entry in ap_expr_eval_ctx_t for use by
     the consumer; an extensible ap_expr_exec_ctx() API that allows to use that
     data entry. [Stefan Fritsch]

  *) mod_include: Merge directory configs instead of one SSI* config directive
     causing all other per-directory SSI* config directives to be reset.
     [Stefan Fritsch]

  *) mod_charset_lite: Remove DebugLevel option in favour of per-module
     loglevel. [Stefan Fritsch]

  *) core: Add ap_regexec_len() function that works with non-null-terminated
     strings. PR 51231. [Yehezkel Horowitz <horowity checkpoint com>]

  *) mod_authnz_ldap: If the LDAP server returns constraint violation,
     don't treat this as an error but as "auth denied". [Stefan Fritsch]

  *) mod_proxy_fcgi|scgi: Add support for "best guess" of PATH_INFO
     for SCGI/FCGI. PR 50880, 50851. [Mark Montague <mark catseye.org>,
     Jim Jagielski]

  *) mod_cache: When content is served stale, and there is no means to
     revalidate the content using ETag or Last-Modified, and we have
     mandated no stale-on-error behaviour, stand down and don't cache.
     Saves a cache write that will never be read.
     [Graham Leggett]

  *) mod_reqtimeout: Fix a timed out connection going into the keep-alive
     state after a timeout when discarding a request body. PR 51103.
     [Stefan Fritsch]

  *) core: Add various file existence test operators to ap_expr.
     [Stefan Fritsch]

  *) mod_proxy_express: New mass reverse-proxy switch extension for
     mod_proxy. [Jim Jagielski]

  *) configure: Fix script error when configuring module set "reallyall".
     [Rainer Jung]

Changes with Apache 2.3.12

  *) configure, core: Provide easier support for APR's hook probe
     capability. [Jim Jagielski, Jeff Trawick]

  *) Silence autoconf 2.68 warnings.  [Rainer Jung]

  *) mod_authnz_ldap: Resolve crash when LDAP is used for authorization only
     [Scott Hill <shill genscape.com>]

  *) support: Make sure check_forensic works with mod_unique_id loaded
     [Joe Schaefer]

  *) Add child_status hook for tracking creation/termination of MPM child
     processes.  Add end_generation hook for notification when the last
     MPM child of a generation exits. [Jeff Trawick]

  *) mod_ldap: Make LDAPSharedCacheSize 0 create a non-shared-memory cache per
     process as opposed to disabling caching completely. This allows to use
     the non-shared-memory cache as a workaround for the shared memory cache
     not being available during graceful restarts. PR 48958. [Stefan Fritsch]

  *) Add new ap_reserve_module_slots/ap_reserve_module_slots_directive API,
     necessary if a module (like mod_perl) registers additional modules late
     in the startup phase. [Stefan Fritsch]

  *) core: Prevent segfault if DYNAMIC_MODULE_LIMIT is reached. PR 51072.
     [Torsten Förtsch <torsten foertsch gmx net>]

  *) WinNT MPM: Improve robustness under heavy load.  [Jeff Trawick]

  *) MinGW build improvements.  PR 49535.  [John Vandenberg
     <jayvdb gmail.com>, Jeff Trawick]

  *) core: Support module names with colons in loglevel configuration.
     [Torsten Förtsch <torsten foertsch gmx net>]

  *) mod_ssl, ab: Support OpenSSL compiled without SSLv2 support.
     [Stefan Fritsch]

  *) core: Abort if the MPM is changed across restart.  [Jeff Trawick]

  *) mod_proxy_ajp: Add support for 'ProxyErrorOverride on'. PR 50945.
     [Peter Pramberger <peter pramberger.at>, Jim Jagielski]

  *) mod_proxy_fcgi: Add support for 'ProxyErrorOverride on'. PR 50913.
     [Mark Montague <mark catseye.org>, Jim Jagielski]

  *) core: Change the APIs of ap_cfg_getline() and ap_cfg_getc() to return an
     error code. Abort with a nice error message if a config line is too long.
     Partial fix for PR 50824. [Stefan Fritsch]

  *) mod_info: Dump config to stdout during startup if -DDUMP_CONFIG is
     specified. PR 31956. [Stefan Fritsch]

  *) Restore visibility of DEFAULT_PIDLOG to core and modules.  MPM
     helper function ap_remove_pid() added.  [Jeff Trawick]

  *) Enable DEFAULT_REL_RUNTIMEDIR on Windows and NetWare.  [various]

  *) Correct C++ incompatibility with http_log.h.  [Stefan Fritsch, Jeff
     Trawick]

  *) mod_log_config: Prevent segfault. PR 50861. [Torsten Förtsch
     <torsten.foertsch gmx.net>]

  *) core: AllowEncodedSlashes new option NoDecode to allow encoded slashes
     in request URL path info but not decode them. Change behavior of option
     "On" to decode the encoded slashes as 2.0 and 2.2 do.  PR 35256,
     PR 46830.  [Dan Poirier]

  *) mod_ssl: Check SNI hostname against Host header case-insensitively.
     PR 49491.  [Mayank Agrawal <magrawal.08 gmail.com>]

  *) mod_ldap: Add LDAPConnectionPoolTTL to give control over lifetime
     of bound backend LDAP connections.  PR47634 [Eric Covener]

  *) mod_cache: Make CacheEnable and CacheDisable configurable per
     directory in addition to per server, making them work from within
     a LocationMatch. [Graham Leggett]

  *) worker, event, prefork: Correct several issues when built as
     DSOs; most notably, the scoreboard was reinitialized during graceful
     restart, such that processes of the previous generation were not
     observable.  [Jeff Trawick]

Changes with Apache 2.3.11

  *) mod_win32: Added shebang check for '! so that .vbs scripts work as CGI.
     Win32's cscript interpreter can only use a single quote as comment char.
     [Guenter Knauf]

  *) mod_proxy: balancer-manager now uses POST instead of GET.
     [Jim Jagielski]

  *) core: new util function: ap_parse_form_data(). Previously,
     this capability was tucked away in mod_request. [Jim Jagielski]

  *) core: new hook: ap_run_pre_read_request. [Jim Jagielski]

  *) modules: Fix many modules that were not correctly initializing if they
     were not active during server startup but got enabled later during a
     graceful restart. [Stefan Fritsch]

  *) core: Create new ap_state_query function that allows modules to determine
     if the current configuration run is the initial one at server startup,
     and if the server is started for testing/config dumping only.
     [Stefan Fritsch]

  *) mod_proxy: Runtime configuration of many parameters for existing
     balancers via the balancer-manager. [Jim Jagielski]

  *) mod_proxy: Runtime addition of new workers (BalancerMember) for existing
     balancers via the balancer-manager. [Jim Jagielski]

  *) mod_cache: When a bad Expires date is present, we need to behave as if
     the Expires is in the past, not as if the Expires is missing. PR 16521.
     [Co-Advisor <coad measurement-factory.com>]

  *) mod_cache: We must ignore quoted-string values that appear in a
     Cache-Control header. PR 50199. [Graham Leggett]

  *) mod_dav: Revert change to send 501 error if unknown Content-* header is
    received for a PUT request. PR 42978. [Stefan Fritsch]

  *) mod_cache: Respect s-maxage as described by RFC2616 14.9.3, which must
     take precedence if present. PR 35247. [Graham Leggett]

  *) mod_ssl: Fix a possible startup failure if multiple SSL vhosts
     are configured with the same ServerName and private key file.
     [Masahiro Matsuya <mmatsuya redhat.com>, Joe Orton]

  *) mod_socache_dc: Make module compile by fixing some typos.
     PR 50735 [Mark Montague <mark catseye.org>]

  *) prefork: Update MPM state in children during a graceful stop or
     restart.  PR 41743.  [Andrew Punch <andrew.punch 247realmedia.com>]

  *) mod_mime: Ignore leading dots when looking for mime extensions.
     PR 50434 [Stefan Fritsch]

  *) core: Add support to set variables with the 'Define' directive. The
     variables that can then be used in the config using the ${VAR} syntax
     known from envvar interpolation. [Stefan Fritsch]

  *) mod_proxy_http: make adding of X-Forwarded-* headers configurable.
     ProxyAddHeaders defaults to On. [Vincent Deffontaines]

  *) mod_slotmem_shm: Increase memory alignment for slotmem data.
     [Rainer Jung]

  *) mod_ssl: Add config options for OCSP: SSLOCSPResponderTimeout,
     SSLOCSPResponseMaxAge, SSLOCSPResponseTimeSkew.
     [Kaspar Brand <httpd-dev.2011 velox.ch>]

  *) mod_ssl: Revamp output buffering to reduce network overhead for
     output fragmented into many buckets, such as chunked HTTP responses.
     [Joe Orton]

  *) core: Apply <If> sections to all requests, not only to file base requests.
     Allow to use <If> inside <Directory>, <Location>, and <Files> sections.
     The merging of <If> sections now happens after the merging of <Location>
     sections, even if an <If> section is embedded inside a <Directory> or
     <Files> section.  [Stefan Fritsch]

  *) mod_proxy: Refactor usage of shared data by dropping the scoreboard
     and using slotmem. Create foundation for dynamic growth/changes of
     members within a balancer. Remove BalancerNonce in favor of a
     per-balancer 'nonce' parameter. [Jim Jagielski]

  *) mod_status: Don't show slots which are disabled by MaxClients as open.
     PR 47022 [Jordi Prats <jordi prats gmail com>, Stefan Fritsch]

  *) mpm_prefork: Fix ap_mpm_query results for AP_MPMQ_MAX_DAEMONS and
     AP_MPMQ_MAX_THREADS.

  *) mod_authz_core: Fix bug in merging logic if user-based and non-user-based
     authorization directives were mixed. [Stefan Fritsch]

  *) mod_authn_socache: change directive name from AuthnCacheProvider
     to AuthnCacheProvideFor.  The term "provider" is overloaded in
     this module, and we should avoid confusion between the provider
     of a backend (AuthnCacheSOCache) and the authn provider(s) for
     which this module provides cacheing (AuthnCacheProvideFor).
     [Nick Kew]

  *) mod_proxy_http: Allocate the fake backend request from a child pool
     of the backend connection, instead of misusing the pool of the frontend
     request. Fixes a thread safety issue where buckets set aside in the
     backend connection leak into other threads, and then disappear when
     the frontend request is cleaned up, in turn causing corrupted buckets
     to make other threads spin. [Graham Leggett]

  *) mod_ssl: Change the format of the SSL_{CLIENT,SERVER}_{I,S}_DN variables
     to be RFC 2253 compatible, convert non-ASCII characters to UTF8, and
     escape other special characters with backslashes. The old format can
     still be used with the LegacyDNStringFormat argument to SSLOptions.

  *) core, mod_rewrite: Make the REQUEST_SCHEME variable available to
     scripts and mod_rewrite. [Stefan Fritsch]

  *) mod_rewrite: Allow to use arbitrary boolean expressions (ap_expr) in
     RewriteCond. [Stefan Fritsch]

  *) mod_rewrite: Allow to unset environment variables using E=!VAR.
     PR 49512. [Mark Drayton <mark markdrayton info>, Stefan Fritsch]

  *) mod_headers: Restore the 2.3.8 and earlier default for the first
     argument of the Header directive ("onsuccess").  [Eric Covener]

  *) core: Disallow the mixing of relative and absolute Options PR 33708.
     [Sönke Tesch <st kino-fahrplan.de>]

  *) core: When exporting request headers to HTTP_* environment variables,
     drop variables whose names contain invalid characters. Describe in the
     docs how to restore the old behaviour. [Malte S. Stretz <mss apache org>]

  *) core: When selecting an IP-based virtual host, favor an exact match for
     the port over a wildcard (or omitted) port instead of favoring the one
     that came first in the configuration file. [Eric Covener]

  *) core: Overlapping virtual host address/port combinations  now implicitly
     enable name-based virtual hosting for that address.  The NameVirtualHost
     directive has no effect, and _default_ is interpreted the same as "*".
     [Eric Covener]

  *) core: In the absence of any Options directives, the default is now
     "FollowSymlinks" instead of "All".  [Igor Galić]

  *) rotatelogs: Add -e option to write logs through to stdout for optional
     further processing. [Graham Leggett]

  *) mod_ssl: Correctly read full lines in input filter when the line is
     incomplete during first read. PR 50481. [Ruediger Pluem]

  *) mod_authz_core: Add AuthzSendForbiddenOnFailure directive to allow
     sending '403 FORBIDDEN' instead of '401 UNAUTHORIZED' if authorization
     fails for an authenticated user. PR 40721. [Stefan Fritsch]

Changes with Apache 2.3.10

  *) mod_rewrite: Don't implicitly URL-escape the original query string
     when no substitution has changed it. PR 50447. [Eric Covener]

  *) core: Honor 'AcceptPathInfo OFF' during internal redirects,
     such as per-directory mod_rewrite substitutions.  PR 50349.
     [Eric Covener]

  *) mod_rewrite: Add 'RewriteOptions InheritBefore' to put the base
     rules/conditions before the overridden rules/conditions.  PR 39313.
     [Jérôme Grandjanny <jerome.grandjanny cea.fr>]

  *) mod_autoindex: add IndexIgnoreReset to reset the list of IndexIgnored
     filenames in higher precedence configuration sections.  PR 24243.
     [Eric Covener]

  *) mod_cgid: RLimit* directive support for mod_cgid.  PR 42135
     [Eric Covener]

  *) core: Fail startup when the argument to ServerName looks like a glob
     or a regular expression instead of a hostname (*?[]).  PR 39863
     [Rahul Nair <rahul.g.nair gmail.com>]

  *) mod_userdir: Add merging of enable, disable, and filename arguments
     to UserDir directive, leaving enable/disable of userlists unmerged.
     PR 44076 [Eric Covener]

  *) httpd: When no -k option is provided on the httpd command line, the server
     was starting without checking for an existing pidfile.  PR 50350
     [Eric Covener]

  *) mod_proxy: Put the worker in error state if the SSL handshake with the
     backend fails. PR 50332.
     [Daniel Ruggeri <DRuggeri primary.net>, Ruediger Pluem]

  *) mod_cache_disk: Fix Windows build which was broken after renaming
     the module. [Gregg L. Smith]

Changes with Apache 2.3.9

  *) SECURITY: CVE-2010-1623 (cve.mitre.org)
     Fix a denial of service attack against mod_reqtimeout.
     [Stefan Fritsch]

  *) mod_headers: Change default first argument of Header directive
     from "onsuccess" to "always". [Eric Covener]

  *) mod_include: Add the onerror attribute to the include element,
     allowing an URL to be specified to include on error. [Graham
     Leggett]

  *) mod_cache_disk: mod_disk_cache renamed to mod_cache_disk, to be
     consistent with the naming of other modules. [Graham Leggett]

  *) mod_setenvif: Add SetEnvIfExpr directive to set env var depending on
     expression. [Stefan Fritsch]

  *) mod_proxy: Fix ProxyPassInterpolateEnv directive. PR 50292.
     [Stefan Fritsch]

  *) suEXEC: Add Suexec directive to disable suEXEC without renaming the
     binary (Suexec Off), or force startup failure if suEXEC is required
     but not supported (Suexec On).  Change SuexecUserGroup to fail
     startup instead of just printing a warning if suEXEC is disabled.
     [Jeff Trawick]

  *) core: Add Error directive for aborting startup or htaccess processing
     with a specified error message.  [Jeff Trawick]

  *) mod_rewrite: Fix the RewriteEngine directive to work within a
     location. Previously, once RewriteEngine was switched on globally,
     it was impossible to switch off. [Graham Leggett]

  *) core, mod_include, mod_ssl: Move the expression parser derived from
     mod_include back into mod_include. Replace ap_expr with a parser
     derived from mod_ssl's parser. Make mod_ssl use the new parser. Rework
     ap_expr's public interface and provide hooks for modules to add variables
     and functions. [Stefan Fritsch]

  *) core: Do the hook sorting earlier so that the hooks are properly sorted
     for the pre_config hook and during parsing the config. [Stefan Fritsch]

  *) core: In the absence of any AllowOverride directives, the default is now
     "None" instead of "All".  PR49823 [Eric Covener]

  *) mod_proxy: Don't allow ProxyPass or ProxyPassReverse in
     <Directory> or <Files>. PR47765 [Eric Covener]

  *) prefork/worker/event MPMS: default value (when no directive is present)
     of MaxConnectionsPerChild/MaxRequestsPerChild is changed to 0 from 10000
     to match default configuration and manual. PR47782 [Eric Covener]

  *) proxy_connect: Don't give up in the middle of a CONNECT tunnel
     when the child process is starting to exit.  PR50220. [Eric Covener]

  *) mod_autoindex: Fix inheritance of mod_autoindex directives into
     contexts that don't have any mod_autoindex directives. PR47766.
     [Eric Covener]

  *) mod_rewrite: Add END flag for RewriteRule to prevent further rounds
     of rewrite processing when a per-directory substitution occurs.
     [Eric Covener]

  *) mod_ssl: Make sure to always log an error if loading of CA certificates
     fails. PR 40312. [Paul Tiemann <issues apache org ourdetour com>]

  *) mod_dav: Send 501 error if unknown Content-* header is received for a PUT
     request (RFC 2616 9.6). PR 42978. [Stefan Fritsch]

  *) mod_dav: Send 400 error if malformed Content-Range header is received for
     a put request (RFC 2616 14.16). PR 49825. [Stefan Fritsch]

  *) mod_proxy: Release the backend connection as soon as EOS is detected,
     so the backend isn't forced to wait for the client to eventually
     acknowledge the data. [Graham Leggett]

  *) mod_proxy: Optimise ProxyPass within a Location so that it is stored
     per-directory, and chosen during the location walk. Make ProxyPass
     work correctly from within a LocationMatch. [Graham Leggett]

  *) core: Fix segfault if per-module LogLevel is on virtual host
     scope. PR 50117. [Stefan Fritsch]

  *) mod_proxy: Move the ProxyErrorOverride directive to have per
     directory scope. [Graham Leggett]

  *) mod_allowmethods: New module to deny certain HTTP methods without
     interfering with authentication/authorization. [Paul Querna,
     Igor Galić, Stefan Fritsch]

  *) mod_ssl: Log certificate information and improve error message if client
     cert verification fails. PR 50093, PR 50094. [Lassi Tuura <lat cern ch>,
     Stefan Fritsch]

  *) htcacheclean: Teach htcacheclean to limit cache size by number of
     inodes in addition to size of files. Prevents a cache disk from
     running out of space when many small files are cached.
     [Graham Leggett]

  *) core: Rename MaxRequestsPerChild to MaxConnectionsPerChild, which
     describes more accurately what the directive does. The old name
     still works but logs a warning. [Stefan Fritsch]

  *) mod_cache: Optionally serve stale data when a revalidation returns a
     5xx response, controlled by the CacheStaleOnError directive.
     [Graham Leggett]

  *) htcacheclean: Allow the listing of valid URLs within the cache, with
     the option to list entry metadata such as sizes and times. [Graham
     Leggett]

  *) mod_cache: correctly parse quoted strings in cache headers.
     PR 50199 [Nick Kew]

  *) mod_cache: Allow control over the base URL of reverse proxied requests
     using the CacheKeyBaseURL directive, so that the cache key can be
     calculated from the endpoint URL instead of the server URL. [Graham
     Leggett]

  *) mod_cache: CacheLastModifiedFactor, CacheStoreNoStore, CacheStorePrivate,
     CacheStoreExpired, CacheIgnoreNoLastMod, CacheDefaultExpire,
     CacheMinExpire and CacheMaxExpire can be set per directory/location.
     [Graham Leggett]

  *) mod_disk_cache: CacheMaxFileSize, CacheMinFileSize, CacheReadSize and
     CacheReadTime can be set per directory/location. [Graham Leggett]

  *) core: Speed up config parsing if using a very large number of config
     files. PR 50002 [andrew cloudaccess net]

  *) mod_cache: Support the caching of HEAD requests. [Graham Leggett]

  *) htcacheclean: Allow the option to round up file sizes to a given
     block size, improving the accuracy of disk usage. [Graham Leggett]

  *) mod_ssl: Add authz providers for use with mod_authz_core and its
     RequireAny/RequireAll containers: 'ssl' (equivalent to SSLRequireSSL),
     'ssl-verify-client' (for use with 'SSLVerifyClient optional'), and
     'ssl-require' (expressions with same syntax as SSLRequire).
     [Stefan Fritsch]

  *) mod_ssl: Make the ssl expression parser thread-safe. It now requires
     bison instead of yacc. [Stefan Fritsch]

  *) mod_disk_cache: Change on-disk header file format to support the
     link of the device/inode of the data file to the matching header
     file, and to support the option of not writing a data file when
     the data file is empty. [Graham Leggett]

  *) core/mod_unique_id: Add generate_log_id hook to allow to use
     the ID generated by mod_unique_id as error log ID for requests.
     [Stefan Fritsch]

  *) mod_cache: Make sure that we never allow a 304 Not Modified response
     that we asked for to leak to the client should the 304 response be
     uncacheable. PR45341 [Graham Leggett]

  *) mod_cache: Add the cache_status hook to register the final cache
     decision hit/miss/revalidate. Add optional support for an X-Cache
     and/or an X-Cache-Detail header to add the cache status to the
     response. PR48241 [Graham Leggett]

  *) mod_authz_host: Add 'local' provider that matches connections originating
     on the local host. PR 19938. [Stefan Fritsch]

  *) Event MPM: Fix crash accessing pollset on worker thread when child
     process is exiting.  [Jeff Trawick]

  *) core: For process invocation (cgi, fcgid, piped loggers and so forth)
     pass the system library path (LD_LIBRARY_PATH or platform-specific
     variables) along with the system PATH, by default.  Both should be
     overridden together as desired using PassEnv etc; see mod_env.
     [William Rowe]

  *) mod_cache: Introduce CacheStoreExpired, to allow administrators to
     capture a stale backend response, perform If-Modified-Since requests
     against the backend, and serving from the cache all 304 responses.
     This restores pre-2.2.4 cache behavior.  [William Rowe]

  *) mod_rewrite: Introduce <=, >= string comparison operators, and integer
     comparators -lt, -le, -eq, -ge, and -gt.  To help bash users and drop
     the ambiguity of the symlink test "-ltest", introduce -h or -L as
     symlink test operators.  [William Rowe]

  *) mod_cache: Give the cache provider the opportunity to choose to cache
     or not cache based on the buckets present in the brigade, such as the
     presence of a FILE bucket.
     [Graham Leggett]

  *) mod_authz_core: Allow authz providers to check args while reading the
     config and allow to cache parsed args. Move 'all' and 'env' authz
     providers from mod_authz_host to mod_authz_core. Add 'method' authz
     provider depending on the HTTP method.  [Stefan Fritsch]

  *) mod_include: Move the request_rec within mod_include to be
     exposed within include_ctx_t. [Graham Leggett]

  *) mod_include: Reinstate support for UTF-8 character sets by allowing a
     variable being echoed or set to be decoded and then encoded as separate
     steps. PR47686 [Graham Leggett]

  *) mod_cache: Add a discrete commit_entity() provider function within the
     mod_cache provider interface which is called to indicate to the
     provider that caching is complete, giving the provider the opportunity
     to commit temporary files permanently to the cache in an atomic
     fashion. Replace the inconsistent use of error cleanups with a formal
     set of pool cleanups attached to a subpool, which is destroyed on error.
     [Graham Leggett]

  *) mod_cache: Change the signature of the store_body() provider function
     within the mod_cache provider interface to support an "in" brigade
     and an "out" brigade instead of just a single input brigade. This
     gives a cache provider the option to consume only part of the brigade
     passed to it, rather than the whole brigade as was required before.
     This fixes an out of memory and a request timeout condition that would
     occur when the original document was a large file. Introduce
     CacheReadSize and CacheReadTime directives to mod_disk_cache to control
     the amount of data to attempt to cache at a time. [Graham Leggett]

  *) core: Add ErrorLogFormat to allow configuring error log format, including
     additional information that is logged once per connection or request. Add
     error log IDs for connections and request to allow correlating error log
     lines and the corresponding access log entry. [Stefan Fritsch]

  *) core: Disable sendfile by default. [Stefan Fritsch]

  *) mod_cache: Check the request to determine whether we are allowed
     to return cached content at all, and respect a "Cache-Control:
     no-cache" header from a client. Previously, "no-cache" would
     behave like "max-age=0". [Graham Leggett]

  *) mod_cache: Use a proper filter context to hold filter data instead
     of misusing the per-request configuration. Fixes a segfault on trunk
     when the normal handler is used. [Graham Leggett]

  *) mod_cgid: Log a warning if the ScriptSock path is truncated because
     it is too long. PR 49388.  [Stefan Fritsch]

  *) vhosts: Do not allow _default_ in NameVirtualHost, or mixing *
     and non-* ports on NameVirtualHost, or multiple NameVirtualHost
     directives for the same address:port, or NameVirtualHost
     directives with no matching VirtualHosts, or multiple ip-based
     VirtualHost sections for the same address:port.  These were
     previously accepted with a warning, but the behavior was
     undefined.  [Dan Poirier]

  *) mod_remoteip: Fix a segfault when using mod_remoteip in conjunction with
     Allow/Deny. PR 49838.  [Andrew Skalski <voltara gmail.com>]

  *) core: DirectoryMatch can now match on the end of line character ($),
     and sub-directories of matched directories are no longer implicitly
     matched.  PR49809 [Eric Covener]

  *) Regexps: introduce new higher-level regexp utility including parsing
     and executing perl-style regexp ops (e.g s/foo/bar/i) and regexp memory
     [Nick Kew]

  *) Proxy: support setting source address.  PR 29404
     [Multiple contributors iterating through bugzilla,
      Aron Ujvari <xanco nikhok.hu>, Aleksey Midenkov <asm uezku.kemsu.ru>,
      <dan listening-station.net; trunk version Nick Kew]

  *) HTTP protocol: return 400 not 503 if we have to abort due to malformed
     chunked encoding. [Nick Kew]

Changes with Apache 2.3.8

  *) suexec: Support large log files. PR 45856. [Stefan Fritsch]

  *) core: Abort with sensible error message if no or more than one MPM is
     loaded. [Stefan Fritsch]

  *) mod_proxy: Rename erroronstatus to failonstatus.
     [Daniel Ruggeri <DRuggeri primary.net>]

  *) mod_dav_fs: Fix broken "creationdate" property.
     Regression in version 2.3.7. [Rainer Jung]

Changes with Apache 2.3.7

  *) SECURITY: CVE-2010-1452 (cve.mitre.org)
     mod_dav, mod_cache, mod_session: Fix Handling of requests without a path
     segment. PR 49246 [Mark Drayton, Jeff Trawick]

  *) mod_ldap: Properly check the result returned by apr_ldap_init. PR 46076.
     [Stefan Fritsch]

  *) mod_rewrite: Log errors if rewrite map files cannot be opened. PR 49639.
     [Stefan Fritsch]

  *) mod_proxy_http: Support the 'ping' property for backend HTTP/1.1 servers
     via leveraging 100-Continue as the initial "request".
     [Jim Jagielski]

  *) core/mod_authz_core: Introduce new access_checker_ex hook that enables
     mod_authz_core to bypass authentication if access should be allowed by
     IP address/env var/... [Stefan Fritsch]

  *) core: Introduce note_auth_failure hook to allow modules to add support
     for additional auth types. This makes ap_note_auth_failure() work with
     mod_auth_digest again. PR 48807. [Stefan Fritsch]

  *) socache modules: return APR_NOTFOUND when a lookup is not found [Nick Kew]

  *) mod_authn_socache: new module [Nick Kew]

  *) configure: Add reallyall option for --enable-mods-shared. [Stefan Fritsch]

  *) Fix Windows build when using VC6. [Gregg L. Smith <lists glewis com>]

  *) mod_rewrite: Allow to set environment variables without explicitly
     giving a value. [Rainer Jung]

  *) mod_rewrite: Remove superfluous EOL from rewrite logging. [Rainer Jung]

  *) mod_include: recognise "text/html; parameters" as text/html
     PR 49616 [Andrey Chernov <ache nagual.pp.ru>]

  *) CGI vars: allow PATH to be set by SetEnv, consistent with LD_LIBRARY_PATH
     PR 43906 [Nick Kew]

  *) Core: Extra robustness: don't try authz and segfault if authn
     fails to set r->user.  Log bug and return 500 instead.
     PR 42995 [Nick Kew]

  *) HTTP protocol filter: fix handling of longer chunk extensions
     PR 49474 [<tee.bee gmx.de>]

  *) Update SSL cipher suite and add example for SSLHonorCipherOrder.
     [Lars Eilebrecht, Rainer Jung]

  *) move AddOutputFilterByType from core to mod_filter.  This should
     fix nasty side-effects that happen when content_type is set
     more than once in processing a request, and make it fully
     compatible with dynamic and proxied contents. [Nick Kew]

  *) mod_log_config: Implement logging for sub second timestamps and
     request end time.  [Rainer Jung]

Changes with Apache 2.3.6

  *) SECURITY: CVE-2009-3555 (cve.mitre.org)
     mod_ssl: Comprehensive fix of the TLS renegotiation prefix injection
     attack when compiled against OpenSSL version 0.9.8m or later. Introduces
     the 'SSLInsecureRenegotiation' directive to reopen this vulnerability
     and offer unsafe legacy renegotiation with clients which do not yet
     support the new secure renegotiation protocol, RFC 5746.
     [Joe Orton, and with thanks to the OpenSSL Team]

  *) SECURITY: CVE-2009-3555 (cve.mitre.org)
     mod_ssl: A partial fix for the TLS renegotiation prefix injection attack
     by rejecting any client-initiated renegotiations. Forcibly disable
     keepalive for the connection if there is any buffered data readable. Any
     configuration which requires renegotiation for per-directory/location
     access control is still vulnerable, unless using OpenSSL >= 0.9.8l.
     [Joe Orton, Ruediger Pluem, Hartmut Keil <Hartmut.Keil adnovum.ch>]

  *) SECURITY: CVE-2010-0408 (cve.mitre.org)
     mod_proxy_ajp: Respond with HTTP_BAD_REQUEST when the body is not sent
     when request headers indicate a request body is incoming; not a case of
     HTTP_INTERNAL_SERVER_ERROR.  [Niku Toivola <niku.toivola sulake.com>]

  *) SECURITY: CVE-2010-0425 (cve.mitre.org)
     mod_isapi: Do not unload an isapi .dll module until the request
     processing is completed, avoiding orphaned callback pointers.
     [Brett Gervasoni <brettg senseofsecurity.com>, Jeff Trawick]

  *) core: Filter init functions are now run strictly once per request
     before handler invocation.  The init functions are no longer run
     for connection filters.  PR 49328.  [Joe Orton]

  *) core: Adjust the output filter chain correctly in an internal
     redirect from a subrequest, preserving filters from the main
     request as necessary.  PR 17629.  [Joe Orton]

  *) mod_cache: Explicitly allow cache implementations to cache a 206 Partial
     Response if they so choose to do so. Previously an attempt to cache a 206
     was arbitrarily allowed if the response contained an Expires or
     Cache-Control header, and arbitrarily denied if both headers were missing.
     [Graham Leggett]

  *) core: Add microsecond timestamp fractions, process id and thread id
     to the error log. [Rainer Jung]

  *) configure: The "most" module set gets build by default.  [Rainer Jung]

  *) configure: Building dynamic modules (DSO) by default.  [Rainer Jung]

  *) configure: Fix broken VPATH build when using included APR.
     [Rainer Jung]

  *) mod_session_crypto: Fix configure problem when building
     with APR 2 and for VPATH builds with included APR.
     [Rainer Jung]

  *) mod_session_crypto: API compatibility with APR 2 crypto and
     APR Util 1.x crypto. [Rainer Jung]

  *) ab: Fix memory leak with -v2 and SSL. PR 49383.
     [Pavel Kankovsky <peak argo troja mff cuni cz>]

  *) core: Add per-module and per-directory loglevel configuration.
           Add some more trace logging.
     mod_rewrite: Replace RewriteLog/RewriteLogLevel with trace log levels.
     mod_ssl: Replace LogLevelDebugDump with trace log levels.
     mod_ssl/mod_proxy*: Adjust loglevels to be less verbose at levels info
           and debug.
     mod_dumpio:  Replace DumpIOLogLevel with trace log levels.
     [Stefan Fritsch]

  *) mod_ldap: LDAP caching was suppressed (and ldap-status handler returns
     title page only) when any mod_ldap directives were used in VirtualHost
     context.  [Eric Covener]

  *) mod_disk_cache: Decline the opportunity to cache if the response is
     a 206 Partial Content. This stops a reverse proxied partial response
     from becoming cached, and then being served in subsequent responses.
     [Graham Leggett]

  *) mod_deflate: avoid the risk of forwarding data before headers are set.
     PR 49369 [Matthew Steele <mdsteele google.com>]

  *) mod_authnz_ldap: Ensure nested groups are checked when the
     top-level group doesn't have any direct non-group members
     of attributes in AuthLDAPGroupAttribute. [Eric Covener]

  *) mod_authnz_ldap: Search or Comparison during authorization phase
     can use the credentials from the authentication phase
     (AuthLDAPSearchAsUSer,AuthLDAPCompareAsUser).
     PR 48340 [Domenico Rotiroti, Eric Covener]

  *) mod_authnz_ldap: Allow the initial DN search during authentication
     to use the HTTP username/pass instead of an anonymous or hard-coded
     LDAP id (AuthLDAPInitialBindAsUser, AuthLDAPInitialBindPattern).
     [Eric Covener]

  *) mod_authnz_ldap: Publish requested LDAP data with an AUTHORIZE_ prefix
     when this module is used for authorization. See AuthLDAPAuthorizePrefix.
     PR 45584 [Eric Covener]

  *) apxs -q: Stop filtering out ':' characters from the reported values.
     PR 45343.  [Bill Cole]

  *) prefork MPM: Work around possible crashes on child exit in APR reslist
     cleanup code.  PR 43857.  [Tom Donovan]

  *) ab: fix number of requests sent by ab when keepalive is enabled.  PR 48497.
     [Bryn Dole <dole blekko.com>]

  *) Log an error for failures to read a chunk-size, and return 408 instead of
     413 when this is due to a read timeout.  This change also fixes some cases
     of two error documents being sent in the response for the same scenario.
     [Eric Covener] PR49167

  *) mod_proxy_balancer: Add new directive BalancerNonce to allow admin
     to control/set the nonce used in the balancer-manager application.
     [Jim Jagielski]

  *) mod_proxy_connect: Support port ranges in AllowConnect. PR 23673.
     [Stefan Fritsch]

  *) Proxy balancer: support setting error status according to HTTP response
     code from a backend.  PR 48939.  [Daniel Ruggeri <DRuggeri primary.net>]

  *) htcacheclean: Introduce the ability to clean specific URLs from the
     cache, if provided as an optional parameter on the command line.
     [Graham Leggett]

  *) core: Introduce the IncludeStrict directive, which explicitly fails
     server startup if no files or directories match a wildcard path.
     [Graham Leggett]

  *) htcacheclean: Report additional statistics about entries deleted.
     PR 48944. [Mark Drayton mark markdrayton.info]

  *) Introduce SSLFIPS directive to support OpenSSL FIPS_mode; permits all
     builds of mod_ssl to use 'SSLFIPS off' for portability, but the proper
     build of openssl is required for 'SSLFIPS on'.  PR 46270.
     [Dr Stephen Henson <steve openssl.org>, William Rowe]

  *) mod_proxy_http: Log the port of the remote server in various messages.
     PR 48812. [Igor Galić <i galic brainsware org>]

  *) mod_reqtimeout: Do not wrongly enforce timeouts for mod_proxy's backend
     connections and other protocol handlers (like mod_ftp). [Stefan Fritsch]

  *) mod_proxy_ajp: Really regard the operation a success, when the client
     aborted the connection. In addition adjust the log message if the client
     aborted the connection. [Ruediger Pluem]

  *) mod_ssl: Add the 'SSLInsecureRenegotiation' directive, which
     allows insecure renegotiation with clients which do not yet
     support the secure renegotiation protocol.  [Joe Orton]

  *) mod_ssl: Fix a potential I/O hang if a long list of trusted CAs
     is configured for client cert auth. PR 46952.  [Joe Orton]

  *) core: Only log a 408 if it is no keepalive timeout. PR 39785
     [Ruediger Pluem,  Mark Montague <markmont umich.edu>]

  *) support/rotatelogs: Add -L option to create a link to the current
     log file.  PR 48761 [<lyndon orthanc.ca>, Dan Poirier]

  *) mod_ldap: Update LDAPTrustedClientCert to consistently be a per-directory
     setting only, matching most of the documentation and examples.
     PR 46541 [Paul Reder, Eric Covener]

  *) mod_ldap: LDAPTrustedClientCert now accepts CA_DER/CA_BASE64 argument
     types previously allowed only in LDAPTrustedGlobalCert. [Eric Covener]

  *) mod_negotiation: Preserve query string over multiviews negotiation.
     This buglet was fixed for type maps in 2.2.6, but the same issue
     affected multiviews and was overlooked.
     PR 33112 [Joergen Thomsen <apache jth.net>]

  *) mod_ldap: Eliminate a potential crash with multiple LDAPTrustedClientCert
     when some are not password-protected. [Eric Covener]

  *) Fix startup segfault when the Mutex directive is used but no loaded
     modules use httpd mutexes.  PR 48787.  [Jeff Trawick]

  *) Proxy: get the headers right in a HEAD request with
     ProxyErrorOverride, by checking for an overridden error
     before not after going into a catch-all code path.
     PR 41646.  [Nick Kew, Stuart Children]

  *) support/rotatelogs: Support the simplest log rotation case, log
     truncation. Useful when the log is being processed in real time
     using a command like tail. [Graham Leggett]

  *) support/htcacheclean: Teach it how to write a pid file (modelled on
     httpd's writing of a pid file) so that it becomes possible to run
     more than one instance of htcacheclean on the same machine.
     [Graham Leggett]

  *) Log command line on startup, so there's a record of command line
     arguments like -f.  PR 48752.  [Dan Poirier]

  *) Introduce mod_reflector, a handler capable of reflecting POSTed
     request bodies back within the response through the output filter
     stack. Can be used to turn an output filter into a web service.
     [Graham Leggett]

  *) mod_proxy_http: Make sure that when an ErrorDocument is served
     from a reverse proxied URL, that the subrequest respects the status
     of the original request. This brings the behaviour of proxy_handler
     in line with default_handler. PR 47106. [Graham Leggett]

  *) Support wildcards in both the directory and file components of
     the path specified by the Include directive. [Graham Leggett]

  *) mod_proxy, mod_proxy_http: Support remote https proxies
     by using HTTP CONNECT.  PR 19188.
     [Philippe Dutrueux <lilas evidian.com>, Rainer Jung]

  *) apxs: Fix -A and -a options to ignore whitespace in httpd.conf
     [Philip M. Gollucci]

  *) worker: Don't report server has reached MaxClients until it has.
     Add message when server gets within MinSpareThreads of MaxClients.
     PR 46996.  [Dan Poirier]

  *) mod_session: Session expiry was being initialised, but not updated
     on each session save, resulting in timed out sessions when there
     should not have been. Fixed. [Graham Leggett]

  *) mod_log_config: Add the R option to log the handler used within the
     request. [Christian Folini <christian.folini netnea com>]

  *) mod_include: Allow fine control over the removal of Last-Modified and
     ETag headers within the INCLUDES filter, making it possible to cache
     responses if desired. Fix the default value of the SSIAccessEnable
     directive.  [Graham Leggett]

  *) Add new UnDefine directive to undefine a variable. PR 35350.
     [Stefan Fritsch]

  *) Make ap_pregsub(), used by AliasMatch and friends, use the same syntax
     for regex backreferences as mod_rewrite and mod_include: Remove the use
     of '&' as an alias for '$0' and allow to escape any character with a
     backslash. PR 48351. [Stefan Fritsch]

  *) mod_authnz_ldap: If AuthLDAPCharsetConfig is set, also convert the
     password to UTF-8. PR 45318.
     [Johannes Müller <joh_m gmx.de>, Stefan Fritsch]

  *) ab: Fix calculation of requests per second in HTML output. PR 48594.
     [Stefan Fritsch]

  *) mod_authnz_ldap: Failures to map a username to a DN, or to check a user
     password now result in an informational level log entry instead of
     warning level.  [Eric Covener]

Changes with Apache 2.3.5

  *) SECURITY: CVE-2010-0434 (cve.mitre.org)
     Ensure each subrequest has a shallow copy of headers_in so that the
     parent request headers are not corrupted.  Eliminates a problematic
     optimization in the case of no request body.  PR 48359
     [Jake Scott, William Rowe, Ruediger Pluem]

  *) Turn static function get_server_name_for_url() into public
     ap_get_server_name_for_url() and use it where appropriate. This
     fixes mod_rewrite generating invalid URLs for redirects to IPv6
     literal addresses. [Stefan Fritsch]

  *) mod_ldap: Introduce new config option LDAPTimeout to set the timeout
     for LDAP operations like bind and search. [Stefan Fritsch]

  *) mod_proxy, mod_proxy_ftp: Move ProxyFtpDirCharset from mod_proxy to
     mod_proxy_ftp. [Takashi Sato]

  *) mod_proxy, mod_proxy_connect: Move AllowCONNECT from mod_proxy to
     mod_proxy_connect. [Takashi Sato]

  *) mod_cache: Do an exact match of the keys defined by
     CacheIgnoreURLSessionIdentifiers against the querystring instead of
     a partial match.  PR 48401.
     [Dodou Wang <wangdong.08 gmail.com>, Ruediger Pluem]

  *) mod_proxy_balancer: Fix crash in balancer-manager. [Rainer Jung]

  *) Core HTTP: disable keepalive when the Client has sent
     Expect: 100-continue
     but we respond directly with a non-100 response.
     Keepalive here led to data from clients continuing being treated as
     a new request.
     PR 47087 [Nick Kew]

  *) Core: reject NULLs in request line or request headers.
     PR 43039 [Nick Kew]

  *) Core: (re)-introduce -T commandline option to suppress documentroot
     check at startup.
     PR 41887 [Jan van den Berg <janvdberg gmail.com>]

  *) mod_autoindex: support XHTML as equivalent to HTML in IndexOptions,
                    ScanHTMLTitles, ReadmeName, HeaderName
     PR 48416 [Dmitry Bakshaev <dab18 izhnet.ru>, Nick Kew]

  *) Proxy: Fix ProxyPassReverse with relative URL
     Derived (slightly erroneously) from PR 38864 [Nick Kew]

  *) mod_headers: align Header Edit with Header Set when used on Content-Type
     PR 48422 [Cyril Bonté <cyril.bonte free.fr>, Nick Kew>]

  *) mod_headers: Enable multi-match-and-replace edit option
     PR 46594 [Nick Kew]

  *) mod_filter: enable it to act on non-200 responses.
     PR 48377 [Nick Kew]

Changes with Apache 2.3.4

  *) Replace AcceptMutex, LockFile, RewriteLock, SSLMutex, SSLStaplingMutex,
     and WatchdogMutexPath with a single Mutex directive.  Add APIs to
     simplify setup and user customization of APR proc and global mutexes.
     (See util_mutex.h.)  Build-time setting DEFAULT_LOCKFILE is no longer
     respected; set DEFAULT_REL_RUNTIMEDIR instead.  [Jeff Trawick]

  *) http_core: KeepAlive no longer accepts other than On|Off.
     [Takashi Sato]

  *) mod_dav: Remove errno from dav_error interface.  Calls to dav_new_error()
     and dav_new_error_tag() must be adjusted to add an apr_status_t parameter.
     [Jeff Trawick]

  *) mod_authnz_ldap: Add AuthLDAPBindAuthoritative to allow Authentication to
     try other providers in the case of an LDAP bind failure.
     PR 46608 [Justin Erenkrantz, Joe Schaefer, Tony Stevenson]

  *) Build: fix --with-module to work as documented
     PR 43881 [Gez Saunders <gez.saunders virgin.net>]

Changes with Apache 2.3.3

  *) SECURITY: CVE-2009-3095 (cve.mitre.org)
     mod_proxy_ftp: sanity check authn credentials.
     [Stefan Fritsch <sf fritsch.de>, Joe Orton]

  *) SECURITY: CVE-2009-3094 (cve.mitre.org)
     mod_proxy_ftp: NULL pointer dereference on error paths.
     [Stefan Fritsch <sf fritsch.de>, Joe Orton]

  *) mod_ssl: enable support for ECC keys and ECDH ciphers.  Tested against
     OpenSSL 1.0.0b3.  [Vipul Gupta <vipul.gupta sun.com>, Sander Temme]

  *) mod_dav: Include uri when logging a PUT error due to connection abort.
     PR 38149. [Stefan Fritsch]

  *) mod_dav: Return 409 instead of 500 for a LOCK request if the parent
     resource does not exist or is not a collection. PR 43465. [Stefan Fritsch]

  *) mod_dav_fs: Return 409 instead of 500 for Litmus test case copy_nodestcoll
     (a COPY request where the parent of the destination resource does not
     exist). PR 39299. [Stefan Fritsch]

  *) mod_dav_fs: Don't delete the whole file if a PUT with content-range failed.
     PR 42896. [Stefan Fritsch]

  *) mod_dav_fs: Make PUT create files atomically and no longer destroy the
     old file if the transfer aborted. PR 39815. [Paul Querna, Stefan Fritsch]

  *) mod_dav_fs: Remove inode keyed locking as this conflicts with atomically
     creating files. On systems with inode numbers, this is a format change of
     the DavLockDB. The old DavLockDB must be deleted on upgrade.
     [Stefan Fritsch]

  *) mod_log_config: Make ${cookie}C correctly match whole cookie names
     instead of substrings. PR 28037. [Dan Franklin <dan dan-franklin.com>,
     Stefan Fritsch]

  *) vhost: A purely-numeric Host: header should not be treated as a port.
     PR 44979 [Nick Kew]

  *) mod_ldap: Avoid 500 errors with "Unable to set LDAP_OPT_REFHOPLIMIT option to 5"
     when built against openldap by using SDK LDAP_OPT_REFHOPLIMIT defaults unless
     LDAPReferralHopLimit is explicitly configured.
     [Eric Covener]

  *) mod_charset_lite: Honor 'CharsetOptions NoImplicitAdd'.
     [Eric Covener]

  *) mod_ssl: Add support for OCSP Stapling.  PR 43822.
     [Dr Stephen Henson <shenson oss-institute.org>]

  *) mod_socache_shmcb: Allow parens in file name if cache size is given.
     Fixes SSLSessionCache directive mis-parsing parens in pathname.
     PR 47945. [Stefan Fritsch]

  *) htpasswd: Improve out of disk space handling. PR 30877. [Stefan Fritsch]

  *) htpasswd: Use MD5 hash by default on all platforms. [Stefan Fritsch]

  *) mod_sed: Reduce memory consumption when processing very long lines.
     PR 48024 [Basant Kumar Kukreja <basant.kukreja sun.com>]

  *) ab: Fix segfault in case the argument for -n is a very large number.
     PR 47178. [Philipp Hagemeister <oss phihag.de>]

  *) Allow ProxyPreserveHost to work in <Proxy> sections. PR 34901.
     [Stefan Fritsch]

  *) configure: Fix THREADED_MPMS so that mod_cgid is enabled again
     for worker MPM. [Takashi Sato]

  *) mod_dav: Provide a mechanism to obtain the request_rec and pathname
     from the dav_resource. [Jari Urpalainen <jari.urpalainen nokia.com>,
     Brian France <brian brianfrance.com>]

  *) Build: Use install instead of cp if available on installing
     modules to avoid segmentation fault. PR 47951. [hirose31 gmail.com]

  *) mod_cache: correctly consider s-maxage in cacheability
     decisions.  [Dan Poirier]

  *) mod_logio/core: Report more accurate byte counts in mod_status if
     mod_logio is loaded. PR 25656. [Stefan Fritsch]

  *) mod_ldap: If LDAPSharedCacheSize is too small, try harder to purge
     some cache entries and log a warning. Also increase the default
     LDAPSharedCacheSize to 500000. This is a more realistic size suitable
     for the default values of 1024 for LdapCacheEntries/LdapOpCacheEntries.
     PR 46749. [Stefan Fritsch]

  *) mod_rewrite: Make sure that a hostname:port isn't fully qualified if
     the request is a CONNECT request. [Bill Zajac <billz consultla.com>]

  *) mod_cache: Teach CacheEnable and CacheDisable to work from within a
     Location section, in line with how ProxyPass works. [Graham Leggett]

  *) mod_reqtimeout: New module to set timeouts and minimum data rates for
     receiving requests from the client. [Stefan Fritsch]

  *) core: Fix potential memory leaks by making sure to not destroy
     bucket brigades that have been created by earlier filters.
     [Stefan Fritsch]

  *) core, mod_deflate, mod_sed: Reduce memory usage by reusing bucket
     brigades in several places. [Stefan Fritsch]

  *) mod_cache: Fix uri_meets_conditions() so that CacheEnable will
     match by scheme, or by a wildcarded hostname. PR 40169
     [Peter Grandi <pg_asf asf.for.sabi.co.uk>, Graham Leggett]

  *) suxec: Allow to log an error if exec fails by setting FD_CLOEXEC
     on the log file instead of closing it. PR 10744. [Nicolas Rachinsky]

  *) mod_mime: Make RemoveType override the info from TypesConfig.
     PR 38330. [Stefan Fritsch]

  *) mod_cache: Introduce the option to run the cache from within the
     normal request handler, and to allow fine grained control over
     where in the filter chain content is cached. Adds CacheQuickHandler
     directive.  [Graham Leggett]

  *) core: Treat timeout reading request as 408 error, not 400.
     Log 408 errors in access log as was done in Apache 1.3.x.
     PR 39785 [Nobutaka Mantani <nobutaka nobutaka.org>,
     Stefan Fritsch <sf fritsch.de>, Dan Poirier]

  *) mod_ssl: Reintroduce SSL_CLIENT_S_DN, SSL_CLIENT_I_DN, SSL_SERVER_S_DN,
     SSL_SERVER_I_DN back to the environment variables to be set by mod_ssl.
     [Peter Sylvester <peter.sylvester edelweb.fr>]

  *) mod_disk_cache: don't cache incomplete responses, per RFC 2616, 13.8.
     PR15866.  [Dan Poirier]

  *) ab: ab segfaults in verbose mode on https sites
     PR46393.  [Ryan Niebur]

  *) mod_dav: Allow other modules to become providers and add resource types
     to the DAV response. [Jari Urpalainen <jari.urpalainen nokia.com>,
     Brian France <brian brianfrance.com>]

  *) mod_dav: Allow other modules to add things to the DAV or Allow headers
     of an OPTIONS request. [Jari Urpalainen <jari.urpalainen nokia.com>,
     Brian France <brian brianfrance.com>]

  *) core: Lower memory usage of core output filter.
     [Stefan Fritsch <sf sfritsch.de>]

  *) mod_mime: Detect invalid use of MultiviewsMatch inside Location and
     LocationMatch sections.  PR47754. [Dan Poirier]

  *) mod_request: Make sure the KeptBodySize directive rejects values
     that aren't valid numbers. [Graham Leggett]

  *) mod_session_crypto: Sanity check should the potentially encrypted
     session cookie be too short. [Graham Leggett]

  *) mod_session.c: Prevent a segfault when session is added but not
     configured. [Graham Leggett]

  *) htcacheclean: 19 ways to fail, 1 error message. Fixed. [Graham Leggett]

  *) mod_auth_digest: Fail server start when nonce count checking
     is configured without shared memory, or md5-sess algorithm is
     configured. [Dan Poirier]

  *) mod_proxy_connect: The connect method doesn't work if the client is
     connecting to the apache proxy through an ssl socket. Fixed.
     PR29744. [Brad Boyer, Mark Cave-Ayland, Julian Gilbey, Fabrice Durand,
     David Gence, Tim Dodge, Per Gunnar Hans, Emmanuel Elango,
     Kevin Croft, Rudolf Cardinal]

  *) mod_ssl: The error message when SSLCertificateFile is missing should
     at least give the name or position of the problematic virtual host
     definition. [Stefan Fritsch sf sfritsch.de]

  *) mod_auth_digest: Fix null pointer when qop=none. [Dan Poirier]

  *) Add support for HTTP PUT to ab. [Jeff Barnes <jbarnesweb yahoo.com>]

  *) mod_headers: generalise the envclause to support expression
     evaluation with ap_expr parser [Nick Kew]

  *) mod_cache: Introduce the thundering herd lock, a mechanism to keep
     the flood of requests at bay that strike a backend webserver as
     a cached entity goes stale. [Graham Leggett]

  *) mod_auth_digest: Fix usage of shared memory and re-enable it.
     PR 16057 [Dan Poirier]

  *) Preserve Port information over internal redirects
     PR 35999 [Jonas Ringh <jonas.ringh cixit.se>]

  *) Proxy: unable to connect to a backend is SERVICE_UNAVAILABLE,
     rather than BAD_GATEWAY or (especially) NOT_FOUND.
     PR 46971 [evanc nortel.com]

  *) Various modules: Do better checking of pollset operations in order to
     avoid segmentation faults if they fail. PR 46467
     [Stefan Fritsch <sf sfritsch.de>]

  *) mod_autoindex: Correctly create an empty cell if the description
     for a file is missing. PR 47682 [Peter Poeml <poeml suse.de>]

  *) ab: Fix broken error messages after resolver or connect() failures.
     [Jeff Trawick]

  *) SECURITY: CVE-2009-1890 (cve.mitre.org)
     Fix a potential Denial-of-Service attack against mod_proxy in a
     reverse proxy configuration, where a remote attacker can force a
     proxy process to consume CPU time indefinitely.  [Nick Kew, Joe Orton]

  *) SECURITY: CVE-2009-1191 (cve.mitre.org)
     mod_proxy_ajp: Avoid delivering content from a previous request which
     failed to send a request body. PR 46949 [Ruediger Pluem]

  *) htdbm: Fix possible buffer overflow if dbm database has very
     long values.  PR 30586 [Dan Poirier]

  *) core: Return APR_EOF if request body is shorter than the length announced
     by the client. PR 33098 [ Stefan Fritsch <sf sfritsch.de>]

  *) mod_suexec: correctly set suexec_enabled when httpd is run by a
     non-root user and may have insufficient permissions.
     PR 42175 [Jim Radford <radford blackbean.org>]

  *) mod_ssl: Fix SSL_*_DN_UID variables to use the 'userID' attribute
     type.  PR 45107.  [Michael Ströder <michael stroeder.com>,
     Peter Sylvester <peter.sylvester edelweb.fr>]

  *) mod_proxy_http: fix case sensitivity checking transfer encoding
     PR 47383 [Ryuzo Yamamoto <ryuzo.yamamoto gmail.com>]

  *) mod_alias: ensure Redirect issues a valid URL.
     PR 44020 [Håkon Stordahl <hakon stordahl.org>]

  *) mod_dir: add FallbackResource directive, to enable admin to specify
     an action to happen when a URL maps to no file, without resorting
     to ErrorDocument or mod_rewrite.  PR 47184 [Nick Kew]

  *) mod_cgid: Do not leak the listening Unix socket file descriptor to the
     CGI process. PR 47335 [Kornél Pál <kornelpal gmail.com>]

  *) mod_rewrite: Remove locking for writing to the rewritelog.
     PR 46942 [Dan Poirier <poirier pobox.com>]

  *) mod_alias: check sanity in Redirect arguments.
     PR 44729 [Sönke Tesch <st kino-fahrplan.de>, Jim Jagielski]

  *) mod_proxy_http: fix Host: header for literal IPv6 addresses.
     PR 47177 [Carlos Garcia Braschi <cgbraschi gmail.com>]

  *) mod_cache: Add CacheIgnoreURLSessionIdentifiers directive to ignore
     defined session identifiers encoded in the URL when caching.
     [Ruediger Pluem]

  *) mod_rewrite: Fix the error string returned by RewriteRule.
     RewriteRule returned "RewriteCond: bad flag delimiters" when the 3rd
     argument of RewriteRule was not started with "[" or not ended with "]".
     PR 45082 [Vitaly Polonetsky <m_vitaly topixoft.com>]

  *) Windows: Fix usage message.
     [Rainer Jung]

  *) apachectl: When passing through arguments to httpd in
     non-SysV mode, use the "$@" syntax to preserve arguments.
     [Eric Covener]

  *) mod_dbd: add DBDInitSQL directive to enable SQL statements to
     be run when a connection is opened.  PR 46827
     [Marko Kevac <mkevac gmail.com>]

  *) mod_cgid: Improve handling of long AF_UNIX socket names (ScriptSock).
     PR 47037.  [Jeff Trawick]

  *) mod_proxy_ajp: Check more strictly that the backend follows the AJP
     protocol. [Mladen Turk]

  *) mod_proxy_ajp: Forward remote port information by default.
     [Rainer Jung]

  *) Allow MPMs to be loaded dynamically, as with most other modules.  Use
     --enable-mpms-shared={list|"all"} to enable.  This required changes to
     the MPM interfaces.  Removed: mpm.h, mpm_default.h (as an installed
     header), APACHE_MPM_DIR, MPM_NAME, ap_threads_per_child,
     ap_max_daemons_limit, ap_my_generation, etc.  ap_mpm_query() can't be
     called until after the register-hooks phase.  [Jeff Trawick]

  *) mod_ssl: Add SSLProxyCheckPeerExpire and SSLProxyCheckPeerCN directives
     to enable stricter checking of remote server certificates.
     [Ruediger Pluem]

  *) ab: Fix a 100% CPU loop on platforms where a failed non-blocking connect
     returns EINPROGRESS and a subsequent poll() returns only POLLERR.
     Observed on HP-UX.  [Eric Covener]

  *) Remove broken support for BeOS, TPF, and even older platforms such
     as A/UX, Next, and Tandem.  [Jeff Trawick]

  *) mod_proxy_ftp: Add ProxyFtpListOnWildcard directive to allow files with
     globbing characters to be retrieved instead of converted into a
     directory listing.  PR 46789 [Dan Poirier <poirier pobox.com>]

  *) Provide ap_retained_data_create()/ap_retained_data_get() for preservation
     of module state across unload/load.  [Jeff Trawick]

  *) mod_substitute: Fix a memory leak. PR 44948
     [Dan Poirier <poirier pobox.com>]

Changes with Apache 2.3.2

  *) mod_mime_magic: Fix detection of compressed content. [Rainer Jung]

  *) mod_negotiation: Escape paths of filenames in 406 responses to avoid
     HTML injections and HTTP response splitting.  PR 46837.
     [Geoff Keating <geoffk apple.com>]

  *) mod_ssl: add support for type-safe STACK constructs in OpenSSL
     development HEAD.  PR 45521.  [Kaspar Brand, Sander Temme]

  *) ab: Fix maintenance of the pollset to resolve EALREADY errors
     with kqueue (BSD/OS X) and excessive CPU with event ports (Solaris).
     PR 44584.  Use APR_POLLSET_NOCOPY for better performance with some
     pollset implementations.  [Jeff Trawick]

  *) mod_disk_cache: The module now turns off sendfile support if
     'EnableSendfile off' is defined globally. [Lars Eilebrecht]

  *) mod_deflate: Adjust content metadata before bailing out on 304
     responses so that the metadata does not differ from 200 response.
     [Roy T. Fielding]

  *) mod_deflate: Fix creation of invalid Etag headers. We now make sure
     that the Etag value is properly quoted when adding the gzip marker.
     PR 39727, 45023. [Lars Eilebrecht, Roy T. Fielding]

  *) Added 20x22 icons for ODF, SVG, and XML documents.  PR 37185.
     [Peter Harlow]

  *) Disabled DefaultType directive and removed ap_default_type()
     from core.  We now exclude Content-Type from responses for which
     a media type has not been configured via mime.types, AddType,
     ForceType, or some other mechanism. PR 13986. [Roy T. Fielding]

  *) mod_rewrite: Add IPV6 variable to RewriteCond
     [Ryan Phillips <ryan-apache trolocsis.com>]

  *) core: Enhance KeepAliveTimeout to support a value in milliseconds.
     PR 46275. [Takashi Sato]

  *) rotatelogs: Allow size units B, K, M, G and combination of
     time and size based rotation. [Rainer Jung]

  *) rotatelogs: Add flag for verbose (debug) output. [Rainer Jung]

  *) mod_ssl: Fix merging of SSLRenegBufferSize directive. PR 46508
     [<tlhackque yahoo.com>]

  *) core: Translate the the status line to ASCII on EBCDIC platforms in
     ap_send_interim_response() and for locally generated "100 Continue"
     responses.  [Eric Covener]

  *) prefork: Fix child process hang during graceful restart/stop in
     configurations with multiple listening sockets.  PR 42829.  [Joe Orton,
     Jeff Trawick]

  *) mod_session_crypto: Ensure that SessionCryptoDriver can only be
     set in the global scope. [Graham Leggett]

  *) mod_ext_filter: We need to detect failure to startup the filter
     program (a mangled response is not acceptable).  Fix to detect
     failure, and offer configuration option either to abort or
     to remove the filter and continue.
     PR 41120 [Nick Kew]

  *) mod_session_crypto: Rewrite the session_crypto module against the
     apr_crypto API. [Graham Leggett]

  *) mod_auth_form: Fix a pool lifetime issue, don't remove the subrequest
     until the main request is cleaned up. [Graham Leggett]

Changes with Apache 2.3.1

  *) ap_slotmem: Add in new slot-based memory access API impl., including
     2 providers (mod_sharedmem and mod_plainmem) [Jim Jagielski,
     Jean-Frederic Clere, Brian Akins <brian.akins turner.com>]

  *) mod_include: support generating non-ASCII characters as entities in SSI
     PR 25202 [Nick Kew]

  *) core/utils: Enhance ap_escape_html API to support escaping non-ASCII chars
     PR 25202 [Nick Kew]

  *) mod_rewrite: fix "B" flag breakage by reverting r5589343
    PR 45529 [Bob Ionescu <bobsiegen googlemail.com>]

  *) CGI: return 504 (Gateway timeout) rather than 500 when a script
     times out before returning status line/headers.
     PR 42190 [Nick Kew]

  *) mod_cgid: fix segfault problem on solaris.
     PR 39332 [Masaoki Kobayashi <masaoki techfirm.co.jp>]

  *) mod_proxy_scgi: Added. [André Malo]

  *) mod_cache: Introduce 'no-cache' per-request environment variable
     to prevent the saving of an otherwise cacheable response.
     [Eric Covener]

  *) mod_rewrite: Introduce DiscardPathInfo|DPI flag to stop the troublesome
     way that per-directory rewrites append the previous notion of PATH_INFO
     to each substitution before evaluating subsequent rules.
     PR 38642 [Eric Covener]

  *) mod_cgid: Do not add an empty argument when calling the CGI script.
     PR 46380 [Ruediger Pluem]

  *) scoreboard: Remove unused sb_type from process_score.
     [Torsten Foertsch <torsten.foertsch gmx.net>, Chris Darroch]

  *) mod_ssl: Add SSLRenegBufferSize directive to allow changing the
     size of the buffer used for the request-body where necessary
     during a per-dir renegotiation.  PR 39243.  [Joe Orton]

  *) mod_proxy_fdpass: New module to pass a client connection over to a separate
     process that is reading from a unix daemon socket.

  *) mod_ssl: Improve environment variable extraction to be more
     efficient and to correctly handle DNs with duplicate tags.
     PR 45975.  [Joe Orton]

  *) Remove the obsolete serial attribute from the RPM spec file. Compile
     against the external pcre. Add missing binaries fcgistarter, and
     mod_socache* and mod_session*. [Graham Leggett]

Changes with Apache 2.3.0

  *) mod_ratelimit: New module to do bandwidth rate limiting. [Paul Querna]

  *) Remove X-Pad header which was added as a work around to a bug in
     Netscape 2.x to 4.0b2. [Takashi Sato <takashi lans-tv.com>]

  *) Add DTrace Statically Defined Tracing (SDT) probes.
    [Theo Schlossnagle <jesus omniti.com>, Paul Querna]

  *) mod_proxy_balancer: Move all load balancing implementations
     as individual, self-contained mod_proxy submodules under
     modules/proxy/balancers [Jim Jagielski]

  *) Rename APIs to include ap_ prefix:
        find_child_by_pid -> ap_find_child_by_pid
        suck_in_APR -> ap_suck_in_APR
        sys_privileges_handlers -> ap_sys_privileges_handlers
        unixd_accept -> ap_unixd_accept
        unixd_config -> ap_unixd_config
        unixd_killpg -> ap_unixd_killpg
        unixd_set_global_mutex_perms -> ap_unixd_set_global_mutex_perms
        unixd_set_proc_mutex_perms -> ap_unixd_set_proc_mutex_perms
        unixd_set_rlimit -> ap_unixd_set_rlimit
     [Paul Querna]

  *) mod_lbmethod_heartbeat: New module to load balance mod_proxy workers
     based on heartbeats. [Paul Querna]

  *) mod_heartmonitor: New module to collect heartbeats, and write out a file
     so that other modules can load balance traffic as needed. [Paul Querna]

  *) mod_heartbeat: New module to generate multicast heartbeats to know if a
     server is online. [Paul Querna]

  *) mod_buffer: Honour the flush bucket and flush the buffer in the
     input filter. Make sure that metadata buckets are written to
     the buffer, not to the final brigade. [Graham Leggett]

  *) mod_buffer: Optimise the buffering of heap buckets when the heap
     buckets stay exactly APR_BUCKET_BUFF_SIZE long. [Graham Leggett,
     Ruediger Pluem]

  *) mod_buffer: Optional support for buffering of the input and output
     filter stacks. Can collapse many small buckets into fewer larger
     buckets, and prevents excessively small chunks being sent over
     the wire. [Graham Leggett]

  *) mod_privileges: new module to make httpd on Solaris privileges-aware
     and to enable different virtualhosts to run with different
     privileges and Unix user/group IDs [Nick Kew]

  *) mod_mem_cache: this module has been removed. [William Rowe]

  *) authn/z: Remove mod_authn_default and mod_authz_default.
     [Chris Darroch]

  *) authz: Fix handling of authz configurations, make default authz
     logic replicate 2.2.x authz logic, and replace <Satisfy*>, Reject,
     and AuthzMergeRules directives with Match, <Match*>, and AuthzMerge
     directives.  [Chris Darroch]

  *) mod_authn_core: Prevent crash when provider alias created to
     provider which is not yet registered.  [Chris Darroch]

  *) mod_authn_core: Add AuthType of None to support disabling
     authentication.  [Chris Darroch]

  *) core: Allow <Limit> and <LimitExcept> directives to nest, and
     constrain their use to conform with that of other access control
     and authorization directives.  [Chris Darroch]

  *) unixd: turn existing code into a module, and turn the set user/group
     and chroot into a child_init function. [Nick Kew]

  *) mod_dir: Support "DirectoryIndex disabled"
     Suggested By André Warnier <aw ice-sa.com> [Eric Covener]

  *) mod_ssl: Send Content-Type application/ocsp-request for POST requests to
     OSCP responders. PR 46014 [Dr Stephen Henson <steve openssl.org>]

  *) mod_authnz_ldap: don't return NULL-valued environment variables to
     other modules.  PR 39045 [Francois Pesce <francois.pesce gmail.com>]

  *) Don't adjust case in pathname components that are not of interest
     to mod_mime.  Fixes mod_negotiation's use of such components.
     PR 43250 [Basant Kumar Kukreja <basant.kukreja sun.com>]

  *) Be tolerant in what you accept - accept slightly broken
     status lines from a backend provided they include a valid status code.
     PR 44995 [Rainer Jung <rainer.jung kippdata.de>]

  *) New module mod_sed: filter Request/Response bodies through sed
     [Basant Kumar Kukreja <basant.kukreja sun.com>]

  *) mod_auth_form: Make sure that basic authentication is correctly
     faked directly after login. [Graham Leggett]

  *) mod_session_cookie, mod_session_dbd: Make sure cookies are set both
     within the output headers and error output headers, so that the
     session is maintained across redirects. [Graham Leggett]

  *) mod_auth_form: Make sure the logged in user is populated correctly
     after a form login. Fixes a missing REMOTE_USER variable directly
     following a login. [Graham Leggett]

  *) mod_session_cookie: Make sure that cookie attributes are correctly
     included in the blank cookie when cookies are removed. This fixes an
     inability to log out when using mod_auth_form. [Graham Leggett]

  *) mod_session: Prevent a segfault when a CGI script sets a cookie with a
     null value. [David Shane Holden <dpejesh apache.org>]

  *) core, authn/z: Determine registered authn/z providers directly in
     ap_setup_auth_internal(), which allows optional functions that just
     wrapped ap_list_provider_names() to be removed from authn/z modules.
     [Chris Darroch]

  *) authn/z: Convert common provider version strings to macros.
     [Chris Darroch]

  *) core: When testing for slash-terminated configuration paths in
     ap_location_walk(), don't look past the start of an empty string
     such as that created by a <Location ""> directive.
     [Chris Darroch]

  *) core, mod_proxy: If a kept_body is present, it becomes safe for
     subrequests to support message bodies. Make sure that safety
     checks within the core and within the proxy are not triggered
     when kept_body is present. This makes it possible to embed
     proxied POST requests within mod_include. [Graham Leggett]

  *) mod_auth_form: Make sure the input filter stack is properly set
     up before reading the login form. Make sure the kept body filter
     is correctly inserted to ensure the body can be read a second
     time safely should the authn be successful. [Graham Leggett,
     Ruediger Pluem]

  *) mod_request: Insert the KEPT_BODY filter via the insert_filter
     hook instead of during fixups. Add a safety check to ensure the
     filters cannot be inserted more than once. [Graham Leggett,
     Ruediger Pluem]

  *) ap_cache_cacheable_headers_out() will (now) always
     merge an error headers _before_ clearing them and _before_
     merging in the actual entity headers and doing normal
     hop-by-hop cleansing. [Dirk-Willem van Gulik].

  *) cache: retire ap_cache_cacheable_hdrs_out() which was used
     for both in- and out-put headers; and replace it by a single
     ap_cache_cacheable_headers() wrapped in a in- and out-put
     specific ap_cache_cacheable_headers_in()/out(). The latter
     which will also merge error and ensure content-type. To keep
     cache modules consistent with ease. This API change bumps
     up the minor MM by one [Dirk-Willem van Gulik].

  *) Move the KeptBodySize directive, kept_body filters and the
     ap_parse_request_body function out of the http module and into a
     new module called mod_request, reducing the size of the core.
     [Graham Leggett]

  *) mod_dbd: Handle integer configuration directive parameters with a
     dedicated function.

  *) Change the directives within the mod_session* modules to be valid
     both inside and outside the location/directory sections, as
     suggested by wrowe. [Graham Leggett]

  *) mod_auth_form: Add a module capable of allowing end users to log
     in using an HTML form, storing the credentials within mod_session.
     [Graham Leggett]

  *) Add a function to the http filters that is able to parse an HTML
     form request with the type of application/x-www-form-urlencoded.
     [Graham Leggett]

  *) mod_session_crypto: Initialise SSL in the post config hook.
     [Ruediger Pluem, Graham Leggett]

  *) mod_session_dbd: Add a session implementation capable of storing
     session information in a SQL database via the dbd interface. Useful
     for sites where session privacy is important. [Graham Leggett]

  *) mod_session_crypto: Add a session encoding implementation capable
     of encrypting and decrypting sessions wherever they may be stored.
     Introduces a level of privacy when sessions are stored on the
     browser. [Graham Leggett]

  *) mod_session_cookie: Add a session implementation capable of storing
     session information within cookies on the browser. Useful for high
     volume sites where server bound sessions are too resource intensive.
     [Graham Leggett]

  *) mod_session: Add a generic session interface to unify the different
     attempts at saving persistent sessions across requests.
     [Graham Leggett]

  *) core, authn/z: Avoid calling access control hooks for internal requests
     with configurations which match those of initial request.  Revert to
     original behaviour (call access control hooks for internal requests
     with URIs different from initial request) if any access control hooks or
     providers are not registered as permitting this optimization.
     Introduce wrappers for access control hook and provider registration
     which can accept additional mode and flag data.  [Chris Darroch]

  *) Introduced ap_expr API for expression evaluation.
     This is adapted from mod_include, which is the first module
     to use the new API.
     [Nick Kew]

  *) mod_authz_dbd: When redirecting after successful login/logout per
     AuthzDBDRedirectQuery, do not report authorization failure, and use
     first row returned by database query instead of last row.
     [Chris Darroch]

  *) mod_ldap: Correctly return all requested attribute values
     when some attributes have a null value.
     PR 44560 [Anders Kaseorg <anders kaseorg.com>]

  *) core: check symlink ownership if both FollowSymlinks and
     SymlinksIfOwnerMatch are set [Nick Kew]

  *) core: fix origin checking in SymlinksIfOwnerMatch
     PR 36783 [Robert L Mathews <rob-apache.org.bugs tigertech.net>]

  *) Activate mod_cache, mod_file_cache and mod_disk_cache as part of the
     'most' set for '--enable-modules' and '--enable-shared-mods'. Include
     mod_mem_cache in 'all' as well. [Dirk-Willem van Gulik]

  *) Also install mod_so.h, mod_rewrite.h and mod_cache.h; as these
     contain public function declarations which are useful for
     third party module authors. PR 42431 [Dirk-Willem van Gulik].

  *) mod_dir, mod_negotiation: pass the output filter information
     to newly created sub requests; as these are later on used
     as true requests with an internal redirect. This allows for
     mod_cache et.al. to trap the results of the redirect.
     [Dirk-Willem van Gulik, Ruediger Pluem]

  *) mod_ldap: Add support (taking advantage of the new APR capability)
     for ldap rebind callback while chasing referrals. This allows direct
     searches on LDAP servers (in particular MS Active Directory 2003+)
     using referrals without the use of the global catalog.
     PRs 26538, 40268, and 42557 [Paul J. Reder]

  *) ApacheMonitor.exe: Introduce --kill argument for use by the
     installer.  This will permit the installation tool to remove
     all running instances before attempting to remove the .exe.
     [William Rowe]

  *) mod_ssl: Add support for OCSP validation of client certificates.
     PR 41123.  [Marc Stern <marc.stern approach.be>, Joe Orton]

  *) mod_serf: New module for Reverse Proxying. [Paul Querna]

  *) core: Add the option to keep aside a request body up to a certain
     size that would otherwise be discarded, to be consumed by filters
     such as mod_include. When enabled for a directory, POST requests
     to shtml files can be passed through to embedded scripts as POST
     requests, rather being downgraded to GET requests. [Graham Leggett]

  *) mod_ssl: Fix TLS upgrade (RFC 2817) support.  PR 41231.  [Joe Orton]

  *) scoreboard: Correctly declare ap_time_process_request.
     PR 43789 [Tom Donovan <Tom.Donovan acm.org>]

  *) core; scoreboard: ap_get_scoreboard_worker(sbh) now takes the sbh member
     from the connection rec, ap_get_scoreboard_worker(proc, thread) will now
     provide the unusual legacy lookup.  [William Rowe]

  *) mpm winnt: fix null pointer dereference
     PR 42572 [Davi Arnaut]

  *) mod_authnz_ldap, mod_authn_dbd: Tidy up the code to expose authn
     parameters to the environment. Improve portability to
     EBCDIC machines by using apr_toupper(). [Martin Kraemer]

  *) mod_ldap, mod_authnz_ldap: Add support for nested groups (i.e. the ability
     to authorize an authenticated user via a "require ldap-group X" directive
     where the user is not in group X, but is in a subgroup contained in X.
     PR 42891 [Paul J. Reder]

  *) mod_ssl: Add support for caching SSL Sessions in memcached. [Paul Querna]

  *) apxs: Enhance -q flag to print all known variables and their values
     when invoked without variable name(s).
     [William Rowe, Sander Temme]

  *) apxs: Eliminate run-time check for mod_so.  PR 40653.
     [David M. Lee <dmlee crossroads.com>]

  *) beos MPM: Create pmain pool and run modules' child_init hooks when
     entering ap_mpm_run(), then destroy pmain when exiting ap_mpm_run().
     [Chris Darroch]

  *) netware MPM: Destroy pmain pool when exiting ap_mpm_run() so that
     cleanups registered in modules' child_init hooks are performed.
     [Chris Darroch]

  *) Fix issue which could cause error messages to be written to access logs
     on Win32.  PR 40476.  [Tom Donovan <Tom.Donovan acm.org>]

  *) The LockFile directive, which specifies the location of
     the accept() mutex lockfile, is deprecated. Instead, the
     AcceptMutex directive now takes an optional lockfile
     location parameter, ala SSLMutex. [Jim Jagielski]

  *) mod_authn_dbd: Export any additional columns queried in the SQL select
     into the environment with the name AUTHENTICATE_<COLUMN>. This brings
     mod_authn_dbd behaviour in line with mod_authnz_ldap. [Graham Leggett]

  *) mod_dbd: Key the storage of prepared statements on the hex string
     value of server_rec, rather than the server name, as the server name
     may change (eg when the server name is set) at any time, causing
     weird behaviour in modules dependent on mod_dbd. [Graham Leggett]

  *) mod_proxy_fcgi: Added win32 build. [Mladen Turk]

  *) sendfile_nonblocking() takes the _brigade_ as an argument, gets
     the first bucket from the brigade, finds it not to be a FILE
     bucket and barfs. The fix is to pass a bucket rather than a brigade.
     [Niklas Edmundsson <nikke acc.umu.se>]

  *) mod_rewrite: support rewritemap by SQL query [Nick Kew]

  *) ap_get_server_version() has been removed.  Third-party modules must
     now use ap_get_server_banner() or ap_get_server_description().
     [Jeff Trawick]

  *) All MPMs: Introduce a check_config phase between pre_config and
     open_logs, to allow modules to review interdependent configuration
     directive values and adjust them while messages can still be logged
     to the console.  Handle relevant MPM directives during this phase
     and format messages for both the console and the error log, as
     appropriate.  [Chris Darroch]

  *) core: Do not allow internal redirects like the DirectoryIndex of mod_dir
     to circumvent the symbolic link checks imposed by FollowSymLinks and
     SymLinksIfOwnerMatch. [Nick Kew, Ruediger Pluem, William Rowe]

  *) New SSLLogLevelDebugDump [ None (default) | IO (not bytes) | Bytes ]
     configures the I/O Dump of SSL traffic, when LogLevel is set to Debug.
     The default is none as this is far greater debugging resolution than
     the typical administrator is prepared to untangle.  [William Rowe]

  *) mod_disk_cache: If possible, check if the size of an object to cache is
     within the configured boundaries before actually saving data.
     [Niklas Edmundsson <nikke acc.umu.se>]

  *) Worker and event MPMs: Remove improper scoreboard updates which were
     performed in the event of a fork() failure.  [Chris Darroch]

  *) Add support for fcgi:// proxies to mod_rewrite.
     [Markus Schiegl <ms schiegl.com>]

  *) Remove incorrect comments from scoreboard.h regarding conditional
     loading of worker_score structure with mod_status, and remove unused
     definitions relating to old life_status field.
     [Chris Darroch <chrisd pearsoncmg.com>]

  *) Remove allocation of memory for unused array of lb_score pointers
     in ap_init_scoreboard().  [Chris Darroch <chrisd pearsoncmg.com>]

  *) Add mod_proxy_fcgi, a FastCGI back end for mod_proxy.
     [Garrett Rooney, Jim Jagielski, Paul Querna]

  *) Event MPM: Fill in the scoreboard's tid field. PR 38736.
     [Chris Darroch <chrisd pearsoncmg.com>]

  *) mod_charset_lite: Remove Content-Length when output filter can
     invalidate it.  Warn when input filter can invalidate it.
     [Jeff Trawick]

  *) Authz: Add the new module mod_authn_core that will provide common
     authn directives such as 'AuthType', 'AuthName'.  Move the directives
     'AuthType' and 'AuthName' out of the core module and merge mod_authz_alias
     into mod_authn_core. [Brad Nicholes]

  *) Authz: Move the directives 'Order', 'Allow', 'Deny' and 'Satisfy'
     into the new module mod_access_compat which can be loaded to provide
     support for these directives.
     [Brad Nicholes]

  *) Authz: Move the 'Require' directive from the core module as well as
     add the directives '<SatisfyAll>', '<SatisfyOne>', '<RequireAlias>'
     and 'Reject' to mod_authz_core. The new directives introduce 'AND/OR'
     logic into the authorization processing. [Brad Nicholes]

  *) Authz: Add the new module mod_authz_core which acts as the
     authorization provider vector and contains common authz
     directives. [Brad Nicholes]

  *) Authz: Renamed mod_authz_dbm authz providers from 'group' and
     'file-group' to 'dbm-group' and 'dbm-file-group'. [Brad Nicholes]

  *) Authz: Added the new authz providers 'env', 'ip', 'host', 'all' to handle
     host-based access control provided by mod_authz_host and invoked
     through the 'Require' directive. [Brad Nicholes]

  *) Authz: Convert all of the authz modules from hook based to
     provider based. [Brad Nicholes]

  *) mod_cache: Add CacheMinExpire directive to set the minimum time in
     seconds to cache a document.
     [Brian Akins <brian.akins turner.com>, Ruediger Pluem]

  *) mod_authz_dbd: SQL authz with Login/Session support [Nick Kew]

  *) Fix typo in ProxyStatus syntax error message.
     [Christophe Jaillet <christophe.jaillet wanadoo.fr>]

  *) Asynchronous write completion for the Event MPM.  [Brian Pane]

  *) Added an End-Of-Request bucket type.  The logging of a request and
     the freeing of its pool are now done when the EOR bucket is destroyed.
     This has the effect of delaying the logging until right after the last
     of the response is sent; ap_core_output_filter() calls the access logger
     indirectly when it destroys the EOR bucket.  [Brian Pane]

  *) Rewrite of logresolve support utility: IPv6 addresses are now supported
     and the format of statistical output has changed. [Colm MacCarthaigh]

  *) Rewrite of ap_coreoutput_filter to do nonblocking writes  [Brian Pane]

  *) Added new connection states for handler and write completion
     [Brian Pane]

  *) mod_cgid: Refuse to work on Solaris 10 due to OS bugs.  PR 34264.
     [Justin Erenkrantz]

  *) Teach mod_ssl to use arbitrary OIDs in an SSLRequire directive,
     allowing string-valued client certificate attributes to be used for
     access control, as in: SSLRequire "value" in OID("1.3.6.1.4.1.18060.1")
     [Martin Kraemer, David Reid]

  [Apache 2.3.0-dev includes those bug fixes and changes with the
   Apache 2.2.xx tree as documented, and except as noted, below.]

Changes with Apache 2.2.x and later:

  *) http://svn.apache.org/viewvc/httpd/httpd/branches/2.2.x/CHANGES?view=markup

Changes with Apache 2.0.x and later:

  *) http://svn.apache.org/viewvc/httpd/httpd/branches/2.0.x/CHANGES?view=markup