Fix logic for determing remote name from remote branch.

git_rebase_update.py

 #!/usr/bin/env python
 # Copyright 2014 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.
 
 """
 Tool to update all branches to have the latest changes from their upstreams.
 """
 
 import argparse
 import collections
 import logging
 import sys
 import textwrap
 
+from fnmatch import fnmatch
 from pprint import pformat
 
 import git_common as git
 
 
 STARTING_BRANCH_KEY = 'depot-tools.rebase-update.starting-branch'
 
 
 def find_return_branch():
   """Finds the branch which we should return to after rebase-update completes.
 
   This value may persist across multiple invocations of rebase-update, if
   rebase-update runs into a conflict mid-way.
   """
   return_branch = git.config(STARTING_BRANCH_KEY)
   if not return_branch:
     return_branch = git.current_branch()
     if return_branch != 'HEAD':
       git.set_config(STARTING_BRANCH_KEY, return_branch)
 
   return return_branch
 
 
 def fetch_remotes(branch_tree):
   """Fetches all remotes which are needed to update |branch_tree|."""
   fetch_tags = False
   remotes = set()
   tag_set = git.tags()
+  fetchspec_map = {}
+  all_fetchspec_configs = git.run(
+      'config', '--get-regexp', r'remote\..*\.fetch').strip()
+  for fetchspec_config in all_fetchspec_configs.splitlines():
+    key, _, fetchspec = fetchspec_config.partition(' ')
+    dest_spec = fetchspec.partition(':')[2]
+    remote_name = key.split('.')[1]
+    fetchspec_map[dest_spec] = remote_name
   for parent in branch_tree.itervalues():
     if parent in tag_set:
       fetch_tags = True
     else:
       full_ref = git.run('rev-parse', '--symbolic-full-name', parent)
-      if full_ref.startswith('refs/remotes'):
-        parts = full_ref.split('/')
-        remote_name = parts[2]
-        remotes.add(remote_name)
+      for dest_spec, remote_name in fetchspec_map.iteritems():
+        if fnmatch(full_ref, dest_spec):
+          remotes.add(remote_name)
+          break
 
   fetch_args = []
   if fetch_tags:
     # Need to fetch all because we don't know what remote the tag comes from :(
     # TODO(iannucci): assert that the tags are in the remote fetch refspec
     fetch_args = ['--all']
   else:
     fetch_args.append('--multiple')
     fetch_args.extend(remotes)
   # TODO(iannucci): Should we fetch git-svn?
@@ skipping 180 matching lines @@
           % (return_branch, root_branch)
         )
       git.run('checkout', root_branch)
     git.set_config(STARTING_BRANCH_KEY, '')
 
   return retcode
 
 
 if __name__ == '__main__':  # pragma: no cover
   sys.exit(main(sys.argv[1:]))