A guide to the various backport scripts:
========================================

There two primary functions:

F1. Auto-merge bot; the nightly svn-role commits.

F2. Conflicts detector bot; the svn-backport-conflicts-1.9.x buildbot task.

And two interactive functions, described later.


The scripts are:

backport.pl:
    oldest script, implements both [F1] and [F2], plus two interactive
    functions¹.  As of March 2015, used in production by svn-role and
    by svn-backport-conflicts-1.9.x.

nominate.pl:
    Symlink to backport.pl.  Implements one of the two interactive features.
    Not used by bots.

backport_tests_pl.py:
    Regression tests for backport.pl.


backport/*.py:
    New Python-based library implementation of STATUS parsing (status.py) and
    of merging nominated revisions (merger.py).  Colloquially referred to as
    'backport.py', even though there is no script by that name.  Written in
    Python 3.

    The modules include their unit tests, see 'python3 -munittest
    backport.status' and 'python3 -munittest backport.merger'.  However,
    changes to these files should be tested both by the unit tests and by the
    backport_tests_py.py blackbox/regression tests.

detect-conflicting-backports.py:
    Implementation of [F2] using backport.py.

merge-approved-backports.py:
    Implementation of [F1] using backport.py.

backport_tests_py.py:
    Regression tests for detect-conflicting-backports.py and merge-approved-backports.py


backport_tests.py:
    Common part of backport_tests_pl.py and backport_tests_py.py.  Uses the
    svntest framework (../../subversion/tests/cmdline/svntest/), which is
    written in Python 2.

backport*.dump:
    Expected output files for backport_tests.py; see the BackportTest
    decorator.


All scripts can be run with '--help' to display their usage messages.


¹ For backport.pl's interactive features, see:
<http://mail-archives.apache.org/mod_mbox/subversion-dev/201503.mbox/%3c20150304225114.GD2036@tarsus.local2%3e>