Add ability to review commit messages.

codereview/views.py

Index: codereview/views.py
===================================================================
--- a/codereview/views.py
+++ b/codereview/views.py
@@ -16,9 +16,11 @@
 
 
 import binascii
+import copy
 import datetime
 import email  # see incoming_mail()
 import email.utils
+import difflib
 import itertools
 import json
 import logging
@@ -1743,6 +1745,10 @@
   patchset = models.PatchSet(issue=issue, data=data, url=url, key=ps_key)
   patchset.put()
 
+  commitPatch = _create_commit_message_patch(patchset,
+                                             patchset.issue.description)
+  commitPatch.put()
+
   if not separate_patches:
     try:
       patches = engine.ParsePatchSet(patchset)
@@ -1828,6 +1834,24 @@
     return show(request, issue.key().id(), form)
   return HttpResponseRedirect(reverse(show, args=[issue.key().id()]))
 
+def _create_commit_message_patch(patchset, description):
+  filename = "COMMIT_MSG"

[tfarina1, 2013/07/26 00:55:56]

Can you rename this to "Commit Message"? So it matches how gerrit does. I'll
really like to see this feature in production :)

[Andi, 2013/07/29 08:38:34]

I'd also would like to see a module constant for this string since we refer to
it in several locations in this module.

[jparent1, 2013/08/14 20:16:52]

Done.

[jparent1, 2013/08/14 20:16:52]

Done.

+
+  diff = ""
+  udiff = difflib.unified_diff("",description.splitlines(1), 
+    fromfile="\dev\\null",tofile=filename)
+  for line in udiff:
+    diff += line
+
+  patch_key = db.Key.from_path(
+    models.Patch.kind(),
+    db.allocate_ids(db.Key.from_path(models.Patch.kind(), 1,
+                                     parent=patchset.key()), 1)[0],
+    parent=patchset.key())
+  commitPatch = models.Patch(patchset=patchset, text=utils.to_dbtext(diff), 
+                             filename=filename, key=patch_key,
+                             no_base_file=True)
+  return commitPatch
 
 def _add_patchset_from_form(request, issue, form, message_key='message',
                             emails_add_only=False):
@@ -1853,6 +1877,10 @@
                              key=ps_key)
   patchset.put()
 
+  commitPatch = _create_commit_message_patch(patchset,
+                                             patchset.issue.description)
+  commitPatch.put()
+
   if not separate_patches:
     try:
       patches = engine.ParsePatchSet(patchset)
@@ -2249,7 +2277,50 @@
 
   was_closed = issue.closed
   issue.subject = cleaned_data['subject']
+  old_description = issue.description
   issue.description = cleaned_data['description']
+ 
+  # If the description was updated, it would get out of sync with the special
+  # COMMIT_MSG file in the last pastchset. So we clone the last patchset,
+  # modulo a new COMMIT_MSG patch. 
+  if issue.description != old_description:
+
+    def clone_without_key(obj, **extra_args):
+      """ Clones an object, without copying the key """
+      klass = obj.__class__
+      props = {}
+      for k, v in klass.properties().iteritems():
+        if not (type(v) == db.DateTimeProperty and
+               (getattr(v, 'auto_now') or getattr(v, 'auto_now_add'))):
+          if type(v) == db.ReferenceProperty:
+            value = getattr(klass, k).get_value_for_datastore(obj)
+          else:
+            value = v.__get__(obj, klass)
+          props[k] = value
+      props.update(extra_args)    
+      return klass(**props)    
+
+    # Create a new patchset from the last one.
+    patchsets = list(issue.patchset_set.order('created'))
+    last_patchset = patchsets[-1]
+    new_patchset_msg = 'Auto-generated patchset by description update.'
+    new_patchset = clone_without_key(last_patchset, parent=issue,
+                                     message=new_patchset_msg)
+    new_patchset.put()
+ 
+    # Add the new commit message patch.
+    commitPatch = _create_commit_message_patch(new_patchset, issue.description)
+    commitPatch.put()
+
+    # And copy all the patches over from last patchset.
+    for patch in list(last_patchset.patch_set):
+      # Skip the old commit message, since we just created a new one.
+      if patch.filename == "COMMIT_MSG":
+          continue
+      new_patch = clone_without_key(patch, parent=new_patchset,
+                                    patchset=new_patchset)
+      new_patch.put()
+
   issue.closed = cleaned_data['closed']
   issue.private = cleaned_data.get('private', False)
   base_changed = (issue.base != base)