Add black/whitelisting to apply_issue

checkout.py

 # coding=utf8
 # 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.
 """Manages a project checkout.
 
 Includes support for svn, git-svn and git.
 """
 
 import ConfigParser
@@ skipping 708 matching lines @@
     self._check_call_git(cmd)
     if self.base_ref:
       base_ref = self.base_ref
     else:
       base_ref = '%s/%s' % (self.remote,
                             self.remote_branch or self.master_branch)
     found_files = self._check_output_git(
         ['diff', base_ref, '--ignore-submodules',
          '--name-only']).splitlines(False)
     assert sorted(patches.filenames) == sorted(found_files), (
-        sorted(patches.filenames), sorted(found_files))
+        'Found extra %s locally, %s not patched' % (
+            sorted(set(found_files) - set(patches.filenames)),
+            sorted(set(patches.filenames) - set(found_files))))
 
   def commit(self, commit_message, user):
     """Commits, updates the commit message and pushes."""
     assert self.commit_user
     assert isinstance(commit_message, unicode)
     current_branch = self._check_output_git(
         ['rev-parse', '--abbrev-ref', 'HEAD']).strip()
     assert current_branch == self.working_branch
 
     commit_cmd = ['commit', '--amend', '-m', commit_message]
@@ skipping 97 matching lines @@
   def revisions(self, rev1, rev2):
     return self.checkout.revisions(rev1, rev2)
 
   @property
   def project_name(self):
     return self.checkout.project_name
 
   @property
   def project_path(self):
     return self.checkout.project_path