Bug 302900

Summary: When cascading CSS drop-shadow filters with the same color, the first filter is only drawn
Product: WebKit Reporter: Said Abou-Hallawa <sabouhallawa>
Component: Layout and RenderingAssignee: Matt Woodrow <mattwoodrow>
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   
See Also: https://bugs.webkit.org/show_bug.cgi?id=303430
Attachments:
Description Flags
test case none

Said Abou-Hallawa
Reported 2025-11-20 15:18:37 PST
Created attachment 477457 [details] test case Open the attached test case which includes two <div> elements with cascading drop-shadow filters Result: The filter of the first element is drawn incorrectly. The filter of the second element is drawn correctly. Expected: The filters of the two <div> elements are cascaded correctly even if the colors of the drop-shadow filters are the same.
Attachments
test case (628 bytes, text/html)
2025-11-20 15:18 PST, Said Abou-Hallawa 		no flags
Details
View All Add attachment proposed patch, testcase, etc.
Radar WebKit Bug Importer
Comment 1 2025-11-20 15:19:01 PST
<rdar://problem/165163823>
Said Abou-Hallawa
Comment 2 2025-11-20 15:41:42 PST
This bugs happens only on Apple platforms. It does not happen also if software filters are used instead of using CoreGraphics. This is an issue below WebKit, tracked by Apple internally as rdar://165163823.
Matt Woodrow
Comment 3 2025-12-08 15:01:54 PST
Re-opening for pull request https://github.com/WebKit/WebKit/pull/55061
EWS
Comment 4 2025-12-09 00:10:43 PST
Committed 304143@main (c887d10d6123): <https://commits.webkit.org/304143@main> Reviewed commits have been landed. Closing PR #55061 and removing active labels.
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