Comment # 27 on bug 1051350 from Michal Srb

(In reply to Max Staudt from comment #26)
> Yeah, but, but, ... looking at the patch, wouldn't that affect *all*
> platforms? This particular bug happens on Gen 4, but not on Gen 6 (Sandy
> Bridge) or other platforms, otherwise we'd hear more complaints. My bet was
> on the Gen4 OpenGL driver in Mesa being borked. Do you think that's the
> wrong place to look?

That particular bug was in path used only with glsl version < 1.30. It is
possible that intel Gen 4 with that version of Mesa is the only platform that
uses glamor and provides only glsl < 1.30. I don't know. You have the hardware
available, check glxinfo and/or try if that patch fixes it.

If it is not that/a bug in glamor, it surely could be a bug in Mesa.