Allow delta links for large files but give appropriate error message when viewing

appengine/chromium_rietveld/codereview/models.py

Index: appengine/chromium_rietveld/codereview/models.py
diff --git a/appengine/chromium_rietveld/codereview/models.py b/appengine/chromium_rietveld/codereview/models.py
index fdfd16fe5587bd0ebe4524b5d7ef8a2039aa7883..00cfcd2d48e3a1292828e74ee5ab3acd1172e6c2 100644
--- a/appengine/chromium_rietveld/codereview/models.py
+++ b/appengine/chromium_rietveld/codereview/models.py
@@ -470,8 +470,6 @@ def _calculate_delta(patch, patchset_id, patchsets):
     A list of patchset ids.
   """
   delta = []
-  if patch.no_base_file:
-    return delta
   for other in patchsets:
     if patchset_id == other.key.id():
       break
@@ -1023,6 +1021,10 @@ class Patch(ndb.Model):
           msg = 'Bad content. Try to upload again.'
           logging.warn('Patch.get_content: %s', msg)
           raise FetchError(msg)
+        if content.file_too_large:
+          msg = 'File too large.'
+          logging.warn('Patch.get_content: %s', msg)
+          raise FetchError(msg)
         if content.is_uploaded and content.text == None:
           msg = 'Upload in progress.'
           logging.warn('Patch.get_content: %s', msg)