Restore under flag historic behaviour of lastchange.py wrt. Git-SVN repos

build/util/lastchange.py

 #!/usr/bin/env python
 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """
 lastchange.py -- Chromium revision fetching utility.
 """
 
 import re
@@ skipping 103 matching lines @@
     if proc.returncode == 0 and output:
       for line in reversed(output.splitlines()):
         if line.startswith('Cr-Commit-Position:'):
           pos = line.rsplit()[-1].strip()
           break
   if not pos:
     return VersionInfo('git', hsh)
   return VersionInfo('git', '%s-%s' % (hsh, pos))
 
 
-def FetchGitSVNURLAndRevision(directory, svn_url_regex):
+def FetchGitSVNURLAndRevision(directory, svn_url_regex, go_deeper):
   """
   Fetch the Subversion URL and revision through Git.
 
   Errors are swallowed.
 
   Returns:
     A tuple containing the Subversion URL and revision.
   """
-  proc = RunGitCommand(directory, ['log', '-1', '--format=%b'])
+  git_args = ['log', '-1', '--format=%b']
+  if go_deeper:
+    git_args.append('--grep=git-svn-id')
+  proc = RunGitCommand(directory, git_args)
   if proc:
     output = proc.communicate()[0].strip()
     if proc.returncode == 0 and output:
       # Extract the latest SVN revision and the SVN URL.
       # The target line is the last "git-svn-id: ..." line like this:
       # git-svn-id: svn://svn.chromium.org/chrome/trunk/src@85528 0039d316....
       match = _GIT_SVN_ID_REGEX.search(output)
       if match:
         revision = match.group(2)
         url_match = svn_url_regex.search(match.group(1))
         if url_match:
           url = url_match.group(2)
         else:
           url = ''
         return url, revision
   return None, None
 
 
-def FetchGitSVNRevision(directory, svn_url_regex):
+def FetchGitSVNRevision(directory, svn_url_regex, go_deeper):
   """
   Fetch the Git-SVN identifier for the local tree.
 
   Errors are swallowed.
   """
-  url, revision = FetchGitSVNURLAndRevision(directory, svn_url_regex)
+  url, revision = FetchGitSVNURLAndRevision(directory, svn_url_regex, go_deeper)
   if url and revision:
     return VersionInfo(url, revision)
   return None
 
 
 def FetchVersionInfo(default_lastchange, directory=None,
-                     directory_regex_prior_to_src_url='chrome|blink|svn'):
+                     directory_regex_prior_to_src_url='chrome|blink|svn',
+                     go_deeper=False):
   """
   Returns the last change (in the form of a branch, revision tuple),
   from some appropriate revision control system.
   """
   svn_url_regex = re.compile(
       r'.*/(' + directory_regex_prior_to_src_url + r')(/.*)')
 
   version_info = (FetchSVNRevision(directory, svn_url_regex) or
-                  FetchGitSVNRevision(directory, svn_url_regex) or
+                  FetchGitSVNRevision(directory, svn_url_regex, go_deeper) or
                   FetchGitRevision(directory))
   if not version_info:
     if default_lastchange and os.path.exists(default_lastchange):
       revision = open(default_lastchange, 'r').read().strip()
       version_info = VersionInfo(None, revision)
     else:
       version_info = VersionInfo(None, None)
   return version_info
 
 def GetHeaderGuard(path):
@@ skipping 64 matching lines @@
                     help="Write last change to FILE. " +
                     "Can be combined with --header to write both files.")
   parser.add_option("", "--header", metavar="FILE",
                     help="Write last change to FILE as a C/C++ header. " +
                     "Can be combined with --output to write both files.")
   parser.add_option("--revision-only", action='store_true',
                     help="Just print the SVN revision number. Overrides any " +
                     "file-output-related options.")
   parser.add_option("-s", "--source-dir", metavar="DIR",
                     help="Use repository in the given directory.")
+  parser.add_option("--git-svn-go-deeper", action='store_true',
+                    help="In a Git-SVN repo, dig down to the last committed " +
+                    "SVN change (historic behaviour).")
   opts, args = parser.parse_args(argv[1:])
 
   out_file = opts.output
   header = opts.header
 
   while len(args) and out_file is None:
     if out_file is None:
       out_file = args.pop(0)
   if args:
     sys.stderr.write('Unexpected arguments: %r\n\n' % args)
     parser.print_help()
     sys.exit(2)
 
   if opts.source_dir:
     src_dir = opts.source_dir
   else:
     src_dir = os.path.dirname(os.path.abspath(__file__))
 
-  version_info = FetchVersionInfo(opts.default_lastchange, src_dir)
+  version_info = FetchVersionInfo(
+    opts.default_lastchange,

[scottmg, 2015/06/18 22:56:34]

this looks oddly indented, if it's not from an autoformatter, please do +4 or
align at (

[mnaganov (inactive), 2015/06/18 22:59:50]

Done.

+    directory=src_dir,
+    go_deeper=opts.git_svn_go_deeper)
 
   if version_info.revision == None:
     version_info.revision = '0'
 
   if opts.revision_only:
     print version_info.revision
   else:
     contents = "LASTCHANGE=%s\n" % version_info.revision
     if not out_file and not opts.header:
       sys.stdout.write(contents)
     else:
       if out_file:
         WriteIfChanged(out_file, contents)
       if header:
         WriteIfChanged(header,
                        GetHeaderContents(header, opts.version_macro,
                                          version_info.revision))
 
   return 0
 
 
 if __name__ == '__main__':
   sys.exit(main())