RESOLVED FIXED254202
[GPU Process] REGRESSION (261700@main): Various "css-backgrounds/background-size-" tests fail with pixel differences 
https://bugs.webkit.org/show_bug.cgi?id=254202
Summary [GPU Process] REGRESSION (261700@main): Various "css-backgrounds/background-s...
Said Abou-Hallawa
Reported 2023-03-21 01:19:28 PDT
There is a slight difference between a frame decoded using CGImageSourceCreateImageAtIndex() and a frame decode using CGImageSourceCreateThumbnailAtIndex(). A thumbnail frame has to be decoded for a certain size which is called sizeForDrawing. The test page draws a tiled background-image by calling BitmapImage::drawPattern() which ends up calling CGImageSourceCreateImageAtIndex(). The expected page draws an HTMLImageElements by calling BitmapImage::draw() which ends up calling CGImageSourceCreateThumbnailAtIndex(). The fix is to switch back to use CGImageSourceCreateImageAtIndex() for small images. This way we can ensure the image is decoded the same way for both the test and the expected pages.
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Said Abou-Hallawa
Comment 1 2023-03-21 01:19:54 PDT
rdar://106952740
Said Abou-Hallawa
Comment 2 2023-03-21 01:25:17 PDT
Pull request: https://github.com/WebKit/WebKit/pull/11750
EWS
Comment 3 2023-03-21 12:33:59 PDT
Committed 261932@main (ff57fe9af291): <https://commits.webkit.org/261932@main> Reviewed commits have been landed. Closing PR #11750 and removing active labels.
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