ref: b47cef056e51751d5d7b1cb50f91a71110294a9c
parent: 850a919640030a7a9813163491cf7c5bde77ce65
author: Yaowu Xu <yaowu@google.com>
date: Thu Oct 10 07:00:57 EDT 2013
change to avoid out-of-range computation Change-Id: Id5e31833a0ef40de9f64c2f5674af7083233bf14