codereview: allow editing of local CL description
between hg clpatch and hg submit.

R=r
https://golang.org/cl/162059
diff --git a/lib/codereview/codereview.py b/lib/codereview/codereview.py
index e333113..0be956b 100644
--- a/lib/codereview/codereview.py
+++ b/lib/codereview/codereview.py
@@ -344,7 +344,14 @@
 			return None, "malformed response loading CL data from code review server"
 		cl.reviewer = SplitCommaSpace(f['reviewers'])
 		cl.cc = SplitCommaSpace(f['cc'])
-		cl.desc = f['description']
+		if cl.local and cl.original_author and cl.desc:
+			# local copy of CL written by someone else
+			# and we saved a description.  use that one,
+			# so that committers can edit the description
+			# before doing hg submit.
+			pass
+		else:
+			cl.desc = f['description']
 		cl.url = server_url_base + name
 		cl.web = True
 	return cl, ''