Bugzilla

Here's a Try run with the attached "patch to demonstrate bug":
https://treeherder.mozilla.org/jobs?repo=try&revision=e5f6458a3aa4f284eecb02d4ff4ec30a7a4ab3ba&selectedTaskRun=Z2-dad7cRmekJxWZbEeCKA.0

I didn't work too hard on the included subtest, so it does actually fail on all platforms, with just fuzzy-failures on Linux and Mac -- this is due to fuzzy antialiasing differences at the edge of the filled-in area -- it's reported as `different: 1022, maxDifference: 142`.  If you look at the actual screenshots, though, you can see that the testcase and reference do actually match visually, and the testcase is rendered in a way that honors the nonzero unwriteable margins.  In contrast: on Windows, the failure is more severe (`different: 17610, maxDifference: 255`), and the data URI screenshots show that the testcase was rendered without any margins at all.

Here's a Try run with the attached "patch to demonstrate bug":
https://treeherder.mozilla.org/jobs?repo=try&revision=e5f6458a3aa4f284eecb02d4ff4ec30a7a4ab3ba&selectedTaskRun=Z2-dad7cRmekJxWZbEeCKA.0

The included test is intended to demonstrate this Windows-specific issue.  I haven't worked too hard on polishing it, so it does actually fail on all platforms, with fuzzy-failures on Linux and Mac -- this is due to fuzzy antialiasing differences at the edge of the filled-in area -- it's reported as `different: 1022, maxDifference: 142`.  If you look at the actual screenshots, though, you can see that the testcase and reference do actually match visually, and the testcase is rendered in a way that honors the nonzero unwriteable margins.  In contrast: on Windows, the failure is more severe (`different: 17610, maxDifference: 255`), and the data URI screenshots show that the testcase was rendered without any margins at all.

Here's a Try run with the attached "patch to demonstrate bug":
https://treeherder.mozilla.org/jobs?repo=try&revision=e5f6458a3aa4f284eecb02d4ff4ec30a7a4ab3ba&selectedTaskRun=Z2-dad7cRmekJxWZbEeCKA.0

The included test is intended to demonstrate this Windows-specific issue.  I haven't worked too hard on polishing it, so it does actually fail on all platforms, with fuzzy-failures on Linux and Mac -- this is due to fuzzy antialiasing differences at the edge of the filled-in area -- it's reported as `different: 1022, maxDifference: 142`.  If you look at the actual screenshots, though, you can see that the testcase and reference do actually match visually, and the testcase is rendered in a way that does honor the nonzero unwriteable margins. (on those platforms).

In contrast: on Windows, the failure is more severe (`different: 17610, maxDifference: 255`), and the data URI screenshots show that the testcase was indeed rendered without any margins at all.