Use "git log" instead of "git svn info" for revision number information, since

tools/utils.py

 # Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 # This file contains a set of utilities functions used by other Python-based
 # scripts.
 
 import commands
 import os
 import platform
@@ skipping 348 matching lines @@
   custom_env['LC_MESSAGES'] = 'en_GB'
   p = subprocess.Popen(['svn', 'info'], stdout = subprocess.PIPE,
                        stderr = subprocess.STDOUT, shell=IsWindows(),
                        env = custom_env,
                        cwd = DART_DIR)
   output, _ = p.communicate()
   revision = ParseSvnInfoOutput(output)
   if revision:
     return revision
 
-  # maybe the builder is using git-svn, try that
+  # Check for revision using git (Note: we can't use git-svn because in a
+  # pure-git checkout, "git-svn anyCommand" just hangs!). We look an arbitrary
+  # number of commits backwards (100) to get past any local commits.
+  p = subprocess.Popen(['git', 'log', '-100'], stdout = subprocess.PIPE,
+      stderr = subprocess.STDOUT, shell=IsWindows(), cwd = DART_DIR)
+  output, _ = p.communicate()
+  revision = ParseGitInfoOutput(output)
+  if revision:
+    return revision
+
+  # In the rare off-chance that git log -100 doesn't have a svn repo number,
+  # attempt to use "git svn info."
   p = subprocess.Popen(['git', 'svn', 'info'], stdout = subprocess.PIPE,
       stderr = subprocess.STDOUT, shell=IsWindows(), cwd = DART_DIR)
   output, _ = p.communicate()
   revision = ParseSvnInfoOutput(output)
   if revision:
     return revision
 
   # Only fail on the buildbot in case of a SVN client version mismatch.
   user = GetUserName()
   if user != 'chrome-bot':
     return '0'
 
   return None
 
+def ParseGitInfoOutput(output):
+  """Given a git log, determine the latest corresponding svn revision."""
+  for line in output.split('\n'):
+    tokens = line.split()
+    if len(tokens) > 0 and tokens[0] == 'git-svn-id:':
+      return tokens[1].split('@')[1]
+  return None
+
 def ParseSvnInfoOutput(output):
   revision_match = re.search('Last Changed Rev: (\d+)', output)
   if revision_match:
     return revision_match.group(1)
   return None
 
 def RewritePathSeparator(path, workspace):
   # Paths in test files are always specified using '/'
   # as the path separator. Replace with the actual
   # path separator before use.
@@ skipping 171 matching lines @@
     os.chdir(self._working_directory)
 
   def __exit__(self, *_):
     print "Enter directory = ", self._old_cwd
     os.chdir(self._old_cwd)
 
 
 if __name__ == "__main__":
   import sys
   Main(sys.argv)