https://bugs.freedesktop.org/show_bug.cgi?id=97477
--- Comment #1 from Nicholas Bishop nicholasbishop@gmail.com --- Posted the patch to the mailing list with a somewhat clearer commit message: https://lists.freedesktop.org/archives/mesa-dev/2016-August/127065.html
FWIW, the process of submitting a patch via the mailing list is a really big barrier to entry for someone new to the project.