Add script to apply a patch from rietveld.

rietveld.py

 # Copyright (c) 2011 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.
 """Defines class Rietveld to easily access a rietveld instance.
 
 Security implications:
 
 The following hypothesis are made:
 - Rietveld enforces:
   - Nobody else than issue owner can upload a patch set
@@ skipping 94 matching lines @@
     Returns a useless diff for binary files.
     """
     url = '/download/issue%s_%s_%s.diff' % (issue, patchset, item)
     return self.get(url)
 
   def get_patch(self, issue, patchset):
     """Returns a PatchSet object containing the details to apply this patch."""
     props = self.get_patchset_properties(issue, patchset) or {}
     out = []
     for filename, state in props.get('files', {}).iteritems():
+      logging.debug('%s' % filename)
       status = state.get('status')
       if status is None:
         raise patch.UnsupportedPatchFormat(
-            filename, 'File\'s status is None, patchset upload is incomplete')
+            filename, 'File\'s status is None, patchset upload is incomplete.')
 
       # TODO(maruel): That's bad, it confuses property change.
       status = status.strip()
 
       if status == 'D':
         # Ignore the diff.
         out.append(patch.FilePatchDelete(filename, state['is_binary']))
       elif status in ('A', 'M'):
         # TODO(maruel): Rietveld support is still weird, add this line once it's
         # safe to use.
         # props = state.get('property_changes', '').splitlines() or []
         props = []
         if state['is_binary']:
           out.append(patch.FilePatchBinary(
               filename,
               self.get_file_content(issue, patchset, state['id']),
               props))
         else:
           if state['num_chunks']:
             diff = self.get_file_diff(issue, patchset, state['id'])
           else:
-            diff = None
+            raise patch.UnsupportedPatchFormat(
+                filename, 'File doesn\'t have a diff.')
           out.append(patch.FilePatchDiff(filename, diff, props))
       else:
         # Line too long (N/80)
         # pylint: disable=C0301
         # TODO: Add support for MM, A+, etc. Rietveld removes the svn properties
         # from the diff.
         # Example of mergeinfo across branches:
         # http://codereview.chromium.org/202046/diff/1/third_party/libxml/xmlcatalog_dummy.cc
         # svn:eol-style property that is lost in the diff
         # http://codereview.chromium.org/202046/diff/1/third_party/libxml/xmllint_dummy.cc
@@ skipping 30 matching lines @@
 
   def post(self, request_path, data, **kwargs):
     ctype, body = upload.EncodeMultipartFormData(data, [])
     return self._send(request_path, payload=body, content_type=ctype, **kwargs)
 
   def _send(self, request_path, **kwargs):
     """Sends a POST/GET to Rietveld.  Returns the response body."""
     maxtries = 5
     for retry in xrange(maxtries):
       try:
+        logging.debug('%s' % request_path)
         result = self.rpc_server.Send(request_path, **kwargs)
         # Sometimes GAE returns a HTTP 200 but with HTTP 500 as the content. How
         # nice.
         return result
       except urllib2.HTTPError, e:
         if retry >= (maxtries - 1):
           raise
         if e.code not in (500, 502, 503):
           raise
       except urllib2.URLError, e:
         if retry >= (maxtries - 1):
           raise
         if not 'Name or service not known' in e.reason:
           # Usually internal GAE flakiness.
           raise
       # If reaching this line, loop again. Uses a small backoff.
       time.sleep(1+maxtries*2)
 
   # DEPRECATED.
   Send = get