Make rietveld status handling saner

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 107 matching lines @@
     """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.')
 
-      # TODO(maruel): That's bad, it confuses property change.
-      status = status.strip()
-
-      if status == 'D':
+      if status[0] == 'D':
+        if status[0] != status.strip():

[Dirk Pranke, 2011/09/06 20:21:48]

Nit: wonder if this might be clearer with 'if status != 'D': ? The strip() and
the [0] seem a bit unnecessary.

[M-A Ruel, 2011/09/06 20:23:59]

No because status is a svn status line, which contains 6 characters, by default
they are spaces, e.g. 'A     '.

[Dirk Pranke, 2011/09/06 22:35:36]

Ah, right. LGTM, then.

+          raise patch.UnsupportedPatchFormat(
+              filename, 'Deleted file shouldn\'t have property change.')
         # Ignore the diff.
         out.append(patch.FilePatchDelete(filename, state['is_binary']))
-      elif status in ('A', 'M'):
+      elif status[0] in ('A', 'M'):
         svn_props = self.parse_svn_properties(
             state.get('property_changes', ''), filename)
         if state['is_binary']:
           out.append(patch.FilePatchBinary(
               filename,
               self.get_file_content(issue, patchset, state['id']),
               svn_props,
               is_new=(status[0] == 'A')))
         else:
           # Ignores num_chunks since it may only contain an header.
+          diff = None
           try:
             diff = self.get_file_diff(issue, patchset, state['id'])
           except urllib2.HTTPError, e:
             if e.code == 404:
               raise patch.UnsupportedPatchFormat(
                   filename, 'File doesn\'t have a diff.')
+            raise
+          # It may happen on property-only change or svn copy without diff.
+          if not diff:
+            # Support this use case if it ever happen.
+            raise patch.UnsupportedPatchFormat(
+                filename, 'Empty diff is not supported yet.\n')
           out.append(patch.FilePatchDiff(filename, diff, svn_props))
           if status[0] == 'A':
             # It won't be set for empty file.
             out[-1].is_new = True
       else:
-        # TODO(maruel): Add support for MM, A+, etc. Rietveld removes the svn
-        # properties from the diff.
-        raise patch.UnsupportedPatchFormat(filename, status)
+        raise patch.UnsupportedPatchFormat(
+            filename, 'Change with status \'%s\' is not supported.' % status)
+
     return patch.PatchSet(out)
 
   @staticmethod
   def parse_svn_properties(rietveld_svn_props, filename):
     """Returns a list of tuple [('property', 'newvalue')].
 
     rietveld_svn_props is the exact format from 'svn diff'.
     """
     rietveld_svn_props = rietveld_svn_props.splitlines()
     svn_props = []
@@ skipping 90 matching lines @@
         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