Bug 261841

Summary: [Filters] Don't override the alpha channel of the GraphicsDropShadow color by the shadow opacity
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   
Bug Depends on:    
Bug Blocks: 261925    

Description Said Abou-Hallawa 2023-09-20 14:09:30 PDT
Creating the GraphicsDropShadow with color equal to 

    auto color = m_shadowColor.colorWithAlpha(m_shadowOpacity);

is wrong since it will override the alpha channel of the drop-shadow filter with the shadow opacity. For example an element with the following css 

    filter: drop-shadow(15px 15px 0px rgba(0, 0, 0, 0.5));

will display a black drop shadow effect for this element. This css filter appears in the expected test page: imported/w3c/web-platform-tests/css/filter-effects/css-filters-animation-drop-shadow-expected.html.
Comment 1 Radar WebKit Bug Importer 2023-09-20 17:09:11 PDT
<rdar://problem/115812347>
Comment 2 Said Abou-Hallawa 2023-09-20 17:14:53 PDT
Pull request: https://github.com/WebKit/WebKit/pull/17997
Comment 3 EWS 2023-09-20 22:07:41 PDT
Committed 268233@main (db985ec58914): <https://commits.webkit.org/268233@main>

Reviewed commits have been landed. Closing PR #17997 and removing active labels.