map-branches: Fix crash with --show-subject when branch name matches files

git_map_branches.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.
 
 """Provides a short mapping of all the branches in your local repo, organized
 by their upstream ('tracking branch') layout.
 
 Example:
 origin/master
@@ skipping 248 matching lines @@
       line.append(back_separator)
 
     # The Rietveld issue associated with the branch.
     if self.verbosity >= 2:
       (url, color) = ('', '') if self.__is_invalid_parent(branch) \
                               else self.__status_info[branch]
       line.append(url or '', color=color)
 
     # The subject of the most recent commit on the branch.
     if self.show_subject:
-      line.append(run('log', '-n1', '--format=%s', branch))
+      line.append(run('log', '-n1', '--format=%s', branch, '--'))
 
     self.output.append(line)
 
     for child in sorted(self.__parent_map.pop(branch, ())):
       self.__append_branch(child, depth=depth + 1)
 
 
 def main(argv):
   setup_color.init()
   if get_git_version() < MIN_UPSTREAM_TRACK_GIT_VERSION:
@@ skipping 25 matching lines @@
   mapper.start()
   print mapper.output.as_formatted_string()
   return 0
 
 if __name__ == '__main__':
   try:
     sys.exit(main(sys.argv[1:]))
   except KeyboardInterrupt:
     sys.stderr.write('interrupted\n')
     sys.exit(1)