Support --target-branch option to git-cl upload for Rietveld

git_cl.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.
 
 # Copyright (C) 2008 Evan Martin <martine@danga.com>
 
 """A git-command for integrating reviews on Rietveld."""
 
 from distutils.version import LooseVersion
@@ skipping 1661 matching lines @@
   git_command = ['push']
   if receive_options:
     git_command.append('--receive-pack=git receive-pack %s' %
                        ' '.join(receive_options))
   git_command += [remote, 'HEAD:refs/for/' + branch]
   RunGit(git_command)
   # TODO(ukai): parse Change-Id: and set issue number?
   return 0
 
 
+def GetTargetRef(remote, remote_branch, target_branch, pending_prefix):
+  """Computes the remote branch ref to use for the CL.
+
+  Args:
+    remote (str): The git remote for the CL.
+    remote_branch (str): The git remote branch for the CL.
+    target_branch (str): The target branch specified by the user.
+    pending_prefix (str): The pending prefix from the settings.
+  """
+  if not (remote and remote_branch):
+    return None
+  
+  if target_branch:
+    # Cannonicalize branch references to the equivalent local full symbolic
+    # refs, which are then translated into the remote full symbolic refs
+    # below.
+    if '/' not in target_branch:
+      remote_branch = 'refs/remotes/%s/%s' % (remote, target_branch)
+    else:
+      prefix_replacements = (
+        ('^((refs/)?remotes/)?branch-heads/', 'refs/remotes/branch-heads/'),
+        ('^((refs/)?remotes/)?%s/' % remote,  'refs/remotes/%s/' % remote),
+        ('^(refs/)?heads/',                   'refs/remotes/%s/' % remote),
+      )
+      match = None
+      for regex, replacement in prefix_replacements:
+        match = re.search(regex, target_branch)
+        if match:
+          remote_branch = target_branch.replace(match.group(0), replacement)
+          break
+      if not match:
+        # This is a branch path but not one we recognize; use as-is.
+        remote_branch = target_branch
+  elif (not remote_branch.startswith('refs/remotes/branch-heads') and
+        not remote_branch.startswith('refs/remotes/%s/refs' % remote)):
+    # Default to master for refs that are not branches.
+    remote_branch = 'refs/remotes/%s/master' % remote
+    
+  # Create the true path to the remote branch.
+  # Does the following translation:
+  # * refs/remotes/origin/refs/diff/test -> refs/diff/test
+  # * refs/remotes/origin/master -> refs/heads/master
+  # * refs/remotes/branch-heads/test -> refs/branch-heads/test
+  if remote_branch.startswith('refs/remotes/%s/refs/' % remote):
+    remote_branch = remote_branch.replace('refs/remotes/%s/' % remote, '')
+  elif remote_branch.startswith('refs/remotes/%s/' % remote):
+    remote_branch = remote_branch.replace('refs/remotes/%s/' % remote,
+                                          'refs/heads/')
+  elif remote_branch.startswith('refs/remotes/branch-heads'):
+    remote_branch = remote_branch.replace('refs/remotes/', 'refs/')
+  # If a pending prefix exists then replace refs/ with it.
+  if pending_prefix:
+    remote_branch = remote_branch.replace('refs/', pending_prefix)
+  return remote_branch
+
+
 def RietveldUpload(options, args, cl, change):
   """upload the patch to rietveld."""
   upload_args = ['--assume_yes']  # Don't ask about untracked files.
   upload_args.extend(['--server', cl.GetRietveldServer()])
   if options.emulate_svn_auto_props:
     upload_args.append('--emulate_svn_auto_props')
 
   change_desc = None
 
   if options.email is not None:
@@ skipping 58 matching lines @@
   if not remote_url:
     if settings.GetIsGitSvn():
       remote_url = cl.GetGitSvnRemoteUrl()
     else:
       if cl.GetRemoteUrl() and '/' in cl.GetUpstreamBranch():
         remote_url = (cl.GetRemoteUrl() + '@'
                       + cl.GetUpstreamBranch().split('/')[-1])
   if remote_url:
     upload_args.extend(['--base_url', remote_url])
     remote, remote_branch = cl.GetRemoteBranch()
-    if remote and remote_branch:
-      # Create the true path to the remote branch.
-      # Does the following translation:
-      # * refs/remotes/origin/refs/diff/test -> refs/diff/test
-      # * refs/remotes/origin/master -> refs/heads/master
-      # * refs/remotes/branch-heads/test -> refs/branch-heads/test
-      if remote_branch.startswith('refs/remotes/%s/refs/' % remote):
-        remote_branch = remote_branch.replace('refs/remotes/%s/' % remote, '')
-      elif remote_branch.startswith('refs/remotes/%s/' % remote):
-        remote_branch = remote_branch.replace('refs/remotes/%s/' % remote,
-                                              'refs/heads/')
-      elif remote_branch.startswith('refs/remotes/branch-heads'):
-        remote_branch = remote_branch.replace('refs/remotes/', 'refs/')
-      pending_prefix = settings.GetPendingRefPrefix()
-      # If a pending prefix exists then replace refs/ with it.
-      if pending_prefix:
-        remote_branch = remote_branch.replace('refs/', pending_prefix)
-      upload_args.extend(['--target_ref', remote_branch])
+    target_ref = GetTargetRef(remote, remote_branch, options.target_branch,
+                              settings.GetPendingRefPrefix())
+    if target_ref:
+      upload_args.extend(['--target_ref', target_ref])
 
   project = settings.GetProject()
   if project:
     upload_args.extend(['--project', project])
 
   try:
     upload_args = ['upload'] + upload_args + args
     logging.info('upload.RealMain(%s)', upload_args)
     issue, patchset = upload.RealMain(upload_args)
     issue = int(issue)
@@ skipping 56 matching lines @@
                     '--emulate-svn-auto-props',
                     action="store_true",
                     dest="emulate_svn_auto_props",
                     help="Emulate Subversion's auto properties feature.")
   parser.add_option('-c', '--use-commit-queue', action='store_true',
                     help='tell the commit queue to commit this patchset')
   parser.add_option('--private', action='store_true',
                     help='set the review private (rietveld only)')
   parser.add_option('--target_branch',
                     '--target-branch',
-                    help='When uploading to gerrit, remote branch to '
-                         'use for CL.  Default: master')
+                    metavar='TARGET',
+                    help='Apply CL to remote ref TARGET.  ' +
+                         'Default: remote branch head, or master')
   parser.add_option('--email', default=None,
                     help='email address to use to connect to Rietveld')
   parser.add_option('--tbr-owners', dest='tbr_owners', action='store_true',
                     help='add a set of OWNERS to TBR')
 
   add_git_similarity(parser)
   (options, args) = parser.parse_args(args)
 
-  if options.target_branch and not settings.GetIsGerrit():
-    parser.error('Use --target_branch for non gerrit repository.')
-
   if is_dirty_git_tree('upload'):
     return 1
 
   options.reviewers = cleanup_list(options.reviewers)
   options.cc = cleanup_list(options.cc)
 
   cl = Changelist()
   if args:
     # TODO(ukai): is it ok for gerrit case?
     base_branch = args[0]
@@ skipping 1057 matching lines @@
         ('AppEngine is misbehaving and returned HTTP %d, again. Keep faith '
           'and retry or visit go/isgaeup.\n%s') % (e.code, str(e)))
 
 
 if __name__ == '__main__':
   # These affect sys.stdout so do it outside of main() to simplify mocks in
   # unit testing.
   fix_encoding.fix_encoding()
   colorama.init()
   sys.exit(main(sys.argv[1:]))