NEW 185837
Animated GIFs with a 90 degree X or Y rotation do not animate 
https://bugs.webkit.org/show_bug.cgi?id=185837
Summary Animated GIFs with a 90 degree X or Y rotation do not animate
Jonathan Deutsch
Reported 2018-05-21 13:46:18 PDT
Created attachment 340881 [details] Repro html and gif file If an animated GIF (either via background-image or img tag) is set to have a 90 degree rotation on the X or Y axis (3d) then it will not animate. If there is no perspective this may make sense as a performance optimization, but it occurs even if perspective is set and the image is being shown. Attachment has a simple repro case. Resizing the window causes a single frame re-render.
Attachments
Repro html and gif file (279.02 KB, application/zip)
2018-05-21 13:46 PDT, Jonathan Deutsch 		no flags
Details
View All Add attachment proposed patch, testcase, etc.
Jonathan Deutsch
Comment 1 2018-05-21 13:49:45 PDT
This occurs on Safari 11. This does not affect Chrome, nor Safari v6.
Radar WebKit Bug Importer
Comment 2 2018-05-23 11:10:51 PDT
<rdar://problem/40491727>
Said Abou-Hallawa
Comment 3 2018-05-23 11:15:39 PDT
This happens because when the <img> element is drawn with perspective css, it is drawn to a layer by getting the current frame and setting its to the layer through GraphicsLayerCA::setContentsToImage(). Getting the current frame by calling BitmapImage::frameImageAtIndexCacheIfNeeded() forces sync image decoding and does start the animation timer for the next frame.
Simon Fraser (smfr)
Comment 4 2018-05-23 11:45:02 PDT
So the "set layer contents to image" code path does the wrong thing with rotated frames? We should turn off the optimization in that case.
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