NEW242399
Content is z-ordered incorrectly 
https://bugs.webkit.org/show_bug.cgi?id=242399
Summary Content is z-ordered incorrectly
Jeff Muizelaar
Reported 2022-07-06 10:57:04 PDT
<div style="width:400px; height: 400px; overflow:scroll"> <div style="height:300px; background-color:blue"></div> <div style="height:300px; background-color:green"></div> </div> <div style="width:200px; height:200px; background-color:red; margin-top:-100px"></div> The red box should be on top of the scrollable area. It is in Chrome and Firefox but not in WebKit.
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Add attachment proposed patch, testcase, etc.
Simon Fraser (smfr)
Comment 1 2022-07-06 11:13:36 PDT
This is the "fundamental compositing bug" where the scroller becomes self-painting, so z-orders on top of the following element with negative margin.
Jeff Muizelaar
Comment 2 2022-07-06 11:38:50 PDT
Are there plans to fix it?
Simon Fraser (smfr)
Comment 3 2022-07-06 11:47:12 PDT
Our current compositing architecture makes this hard to fix in the short term. In the long term, yes.
Radar WebKit Bug Importer
Comment 4 2022-07-11 01:52:58 PDT
<rdar://problem/96815353>
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