1295501 - Either fix or remove test_synchronized_animation.html

Status: NEW

(Core :: Graphics: ImageLib, defect, P3)

Description

[Seth Fowler [:seth] [:s2h]]

I disabled test_synchronized_animation.html in bug 1293472 because it relies on canvas.drawImage() forcing synchronous decoding of *all* frames of an animated image. This behavior is actually just an artifact of the limitations of our previous design; before bug 1293472, we couldn't perform a first-frame-only decode of an animated image, so the only way to decode an animated image was to decode all its frames. Now that we *do* support that, we can avoid decoding the extra frames where possible. However, that breaks test_synchronized_animation.html.

Since this is the only test that is broken by this issue, I'm just disabling it. We'll be able to reenable it once bug streaming-gif is complete, because the only reason this matters at all is that decoding of animated images isn't synchronous and we don't want it to force it to be because we have no mechanism for synchronously decoding one frame at a time. If we could synchronously decode an animated image just enough to get to the frame we needed to display, we could just, well, do that, and it'd fix this test. And, it turns out, that's what we'll end up doing anyway for streaming playback of animated images. So this test will come back online very shortly.

Comment 1

[Seth Fowler [:seth] [:s2h]]

I called this bug "fix or remove", by the way, because an alternate solution to this problem is just to never turn back on the test. The reason is that bug 1257388 will almost certainly render this test obsolete anyway.