User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_2) AppleWebKit/600.3.18 (KHTML, like Gecko) Version/8.0.3 Safari/600.3.18 Steps to reproduce: -unzip attached angle_issue.zip -Open index.html Actual results: You should see a yellow cube on a blue background, which turns blurry after a second. Expected results: When WebGL is using the ANGLE backend, the image will become very dark instead.

I see that with FF35 on Win 7 (animation becomes dark). Is it the normal rendering? If yes, is your bug specific to OSX (eventually Linux)?

Firefox35 on windows renders the WebGL Area black after a second (expected result). The same Firefox version on OSx10.9 doesn't turn dark but my system is using the Nvidia Opencl renderer

Oops, I just realized that my bug submission was badly written, as I have the actual and expected results flipped. Sorry for that. So, the page is showing a shader anti-aliasing effect, which should result in a blurry rendering of the cube. This renders correctly on the OpenGL WebGL backend (OS X, Linux, Windows with ANGLE disabled in about:config). On the ANGLE backend (windows default), however, it will show a dark screen instead. This is the bug.

regression range: good=2014-07-06 bad=2014-07-07 http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=81691a55e60f&tochange=1dc6b294800d Probably: Vladimir Vukicevic — b=1010371, code fixes for new ANGLE version; r=jrmuizel Vladimir Vukicevic — b=1010371; Update ANGLE; r=upstream

I can still repro the difference. (Win10 with NV, my MBP) Not sure what the bug is without more digging. Relatively low priority for now.

Also, no crash happens in either case when using MOZ_GL_DEBUG_ABORT_ON_ERROR=1.