codereview: Mercurial 1.9 fix for hg diff @nnn
codereview: Mercurial 1.9 fix for hg diff @nnn

R=golang-dev, adg
CC=golang-dev
http://codereview.appspot.com/4969063

wesolows/golang,firebitsbr/golang-old,wesolows/golang-old,wesolows/golang,wesolows/golang-old,firebitsbr/golang-old,firebitsbr/golang-old,wesolows/golang,wesolows/golang,wesolows/golang,wesolows/golang-old,wesolows/golang-old,wesolows/golang,firebitsbr/golang-old,firebitsbr/golang-old,wesolows/golang-old,firebitsbr/golang-old,wesolows/golang-old,firebitsbr/golang-old,wesolows/golang,wesolows/golang-old,firebitsbr/golang-old