TS-2654 Crash in Range requests with read-while-writer.

(cherry picked from commit dec4fdb96b135aa92b7146c9dd2f6ff7971f9c5d)

Conflicts:
	CHANGES
diff --git a/CHANGES b/CHANGES
index 3d27b9f..15ab299 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,6 +1,8 @@
                                                          -*- coding: utf-8 -*-
 Changes with Apache Traffic Server 4.2.1
 
+  *) [TS-2654] Crash in Range requests with read-while-writer.
+
   *) [TS-2674] Remove debug printf() from traffic_top.
 
   *) [TS-2671] Restore missing .useflt remap directive.
diff --git a/proxy/http/HttpTransact.cc b/proxy/http/HttpTransact.cc
index 9692d99..61cff99 100644
--- a/proxy/http/HttpTransact.cc
+++ b/proxy/http/HttpTransact.cc
@@ -6732,7 +6732,7 @@
 
       case SOURCE_TRANSFORM:
         if (s->range_setup == HttpTransact::RANGE_REQUESTED) {
-          change_response_header_because_of_range_request(s, header);
+          header->set_content_length(s->range_output_cl);
           s->hdr_info.trust_response_cl = true;
         } else if (s->hdr_info.transform_response_cl == HTTP_UNDEFINED_CL) {
           s->hdr_info.trust_response_cl = false;