Fix regexp used for enumerating remotes.

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
@@ skipping 26 matching lines @@
   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()
+      '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)
@@ skipping 194 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:]))