https://bugs.freedesktop.org/show_bug.cgi?id=104492
--- Comment #5 from florian.will@googlemail.com --- I'm preparing a patch right now with the changes described in my last comment. The patch fixes my test case and I see no piglit regressions (only some unstable tests unrelated to my patch). If I get git send-email to work, I'll send it to the list.