Port of https://golang.org/cl/154360045 to Git.
Original author is Xia Bin <snyh@snyh.org> (already a contributor).

Fixes #8945.

Change-Id: I28bcaf3348794202ca59fbc3466bd7b9670030e4
Reviewed-on: https://go-review.googlesource.com/11658Reviewed-by: Ian Lance Taylor <iant@golang.org>