Bugzilla

Here's another try run where I've edited svg-rotate-angle-45-001.html to remove the red shape entirely; and I added a bunch of rotated green squares for good measure (all of them over the green background):
https://treeherder.mozilla.org/jobs?repo=try&revision=de5b3c887c4a9410e9925baa91fc499420ba9460

Here, everything is styled as "green" i.e. `rgb(0,128,0)`.  Somehow this produces a whole bunch of pixels with +/- 1 in the green color channel at the edges of the rotated shapes, as shown in the failure logs.  So there's some compositing brokenness happening here.

Glenn, is this a known issue with our GPU WebRender backend, and is there anything we can do about it?  (We could just annotate these tests as fuzzy, but it'd be nice to fix the bug and avoid curating the various fuzzy annotations for green-SVG-shapes-over-green-backgrounds, if possible.)

Here's another try run where I've edited svg-rotate-angle-45-001.html to remove the red shape entirely; and I added a bunch of rotated green squares for good measure (all of them over the solid green background, without any holes that need covering-up or anything fancy):
https://treeherder.mozilla.org/jobs?repo=try&revision=de5b3c887c4a9410e9925baa91fc499420ba9460

Here, everything is styled as "green" i.e. `rgb(0,128,0)`.  Somehow this produces a whole bunch of pixels with +/- 1 in the green color channel at the edges of the rotated shapes, as shown in the failure logs.  So there's some compositing brokenness happening here.

Glenn, is this a known issue with our GPU WebRender backend, and is there anything we can do about it?  (We could just annotate these tests as fuzzy, but it'd be nice to fix the bug and avoid curating the various fuzzy annotations for green-SVG-shapes-over-green-backgrounds, if possible.)