git-codereview: guard against ambiguous revision parameters

Change-Id: I3afcf06e1eab28bfdb2c6ace7aaf774070084900
Reviewed-on: https://go-review.googlesource.com/1783
Reviewed-by: Russ Cox <rsc@golang.org>
7 files changed
tree: d4edc0d66cfddcb8730aa8873a3865532b5913e4
  1. .gitattributes
  2. README
  3. git-codereview/