Bug 254202

Summary: [GPU Process] REGRESSION (261700@main): Various "css-backgrounds/background-size-" tests fail with pixel differences
Product: WebKit Reporter: Said Abou-Hallawa <sabouhallawa>
Component: Layout and RenderingAssignee: Said Abou-Hallawa <sabouhallawa>
Status: RESOLVED FIXED    
Severity: Normal CC: bfulgham, simon.fraser, webkit-bug-importer, zalan
Priority: P2 Keywords: InRadar
Version: WebKit Nightly Build   
Hardware: Unspecified   
OS: Unspecified   

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.
Attachments
Said Abou-Hallawa
Comment 1 2023-03-21 01:19:54 PDT
Said Abou-Hallawa
Comment 2 2023-03-21 01:25:17 PDT
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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