Add new tool, git find-releases

git_find_releases.py

Index: git_find_releases.py
diff --git a/git_find_releases.py b/git_find_releases.py
new file mode 100755
index 0000000000000000000000000000000000000000..76e114eedd9a5bc1ce0ba3c8266945110a802680
--- /dev/null
+++ b/git_find_releases.py
@@ -0,0 +1,60 @@
+#!/usr/bin/env python
+# Copyright 2015 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.
+"""Usage: %prog <commit>*
+
+Given a commit, finds the release where it first appeared (e.g. 47.0.2500.0) as
+well as attempting to determine the branches to which it was merged.
+
+Note that it uses the "cherry picked from" annotation to find merges, so it will
+only work on merges that followed the "use cherry-pick -x" instructions.
+"""
+
+import optparse
+import re
+import sys
+
+import git_common as git
+
+
+def GetNameForCommit(sha1):
+  return re.sub(r'~.*$', '', git.run('name-rev', '--tags', '--name-only', sha1))
+
+
+def GetMergesForCommit(sha1):
+  return [c.split()[0] for c in
+          git.run('log', '--oneline', '-F', '--all', '--no-abbrev', '--grep',
+                  'cherry picked from commit %s' % sha1).splitlines()]
+
+
+def main():
+  parser = optparse.OptionParser(usage=sys.modules[__name__].__doc__)
+  _, args = parser.parse_args()
+
+  if len(args) == 0:
+    parser.error('Need at least one commit.')
+
+  for arg in args:
+    commit_name = GetNameForCommit(arg)
+    if not commit_name:
+      print '%s not found' % arg
+      return 1
+    print 'commit %s was:' % arg
+    print '  initially in ' + commit_name
+    merges = GetMergesForCommit(arg)
+    for merge in merges:
+      print '  merged to ' + GetNameForCommit(merge) + ' (as ' + merge + ')'
+    if not merges:
+      print 'No merges found. If this seems wrong, be sure that you did:'
+      print '  git fetch origin && gclient sync --with_branch_heads'
+
+  return 0
+
+
+if __name__ == '__main__':
+  try:
+    sys.exit(main())
+  except KeyboardInterrupt:
+    sys.stderr.write('interrupted\n')
+    sys.exit(1)