Move patch management functions into their own file, patch.py.

pending_manager.py

 # coding=utf8
 # Copyright (c) 2010 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.
 """Commit queue manager class.
 
 Security implications:
 
 The following hypothesis are made:
 - Commit queue:
   - Impersonate the same svn credentials that the patchset owner.
   - Can't impersonate a non committer.
   - SVN will check the committer write access.
 """
 
 import json
 import logging
 import os
 import re
 import sys
 import traceback
 import urllib2
 
 import find_depot_tools  # pylint: disable=W0611
 import breakpad
 
 import model
+import patch
 from verification import base
 
 
 def TODO(string):
   logging.warning(string)
 
 
 def send_stack(e):
   breakpad.SendStack(e,
       ''.join(traceback.format_tb(sys.exc_info()[2])),
       maxlen=2000)
 
 
-def auto_mangle_git_patch(patch):
-  """Mangles a patch and automatically strip out git decoration."""
-  # Git patches have a/ at the beginning of source paths.  We strip that out
-  # with a regexp rather than the -p flag to patch so we can feed either Git
-  # or svn-style patches into the same apply command.  re.sub() should be used
-  # but flags=re.MULTILINE is only in python 2.7.
-  out = []
-  for line in patch.splitlines(True):
-    # TODO: It should just process the header lines.
-    out.append(re.sub(r'^--- a/', r'--- ',
-      re.sub(r'^\+\+\+ b/', r'+++ ', line)))
-  return ''.join(out)
-
-
 class PendingCommit(base.Verified):
   """Represents a pending commit that is being processed."""
   persistent = base.Verified.persistent + [
       # Important since they tell if we need to revalidate and send try jobs
       # again or not if any of these value changes.
       'issue', 'patchset', 'rietveld_server', 'processed',
       # Only a cache, these values can be regenerated.
       'owner', 'reviewers', 'base_url',
       # Only used after a patch was committed. Keeping here for completeness.
       'description', 'revision',
@@ skipping 205 matching lines @@
     self.rietveld.set_flag(pending.issue, pending.patchset, 'commit', 'False')
     if message:
       self.rietveld.add_comment(pending.issue, message)
     try:
       self.queue.pending_commits.remove(pending)
     except ValueError:
       pass
 
   def _apply_patch(self, pending, revision):
     """Applies the pending patch to the checkout and throws if it fails."""
-    patch = urllib2.urlopen(pending.patch_url()).read()
-    patch = auto_mangle_git_patch(patch)
-    if not self.checkout.apply_patch(patch):
+    patch_data = urllib2.urlopen(pending.patch_url()).read()
+    patch_data = patch.auto_mangle_git_patch(patch_data)
+    if not self.checkout.apply_patch(patch_data):
       raise base.DiscardPending(pending,
           'Patch failed to apply against %s.' % revision)
 
   def load(self, filename):
     """Loads the commit queue state from a JSON file."""
     self.queue = model.load_from_json_file(filename)
     self.queue.pending_commits = self.queue.pending_commits or []
 
   def save(self, filename):
     """Save the commit queue state in a simple JSON file."""
     model.save_to_json_file(filename, self.queue)