Bug 126262

Summary: Graphics buffer issue with clip-path and fixed positioned element
Product: WebKit Reporter: Dirk Schulze <krit>
Component: CSSAssignee: Simon Fraser (smfr) <simon.fraser>
Status: RESOLVED FIXED    
Severity: Normal CC: commit-queue, dino, esprehn+autocc, glenn, kondapallykalyan, rniwa, simon.fraser, webkit-bug-importer
Priority: P2 Keywords: InRadar
Version: 528+ (Nightly build)   
Hardware: Unspecified   
OS: Unspecified   
Bug Depends on:    
Bug Blocks: 126207    
Attachments:
Description Flags
Example
none
Patch thorton: review+

Dirk Schulze
Reported 2013-12-27 07:07:58 PST
Created attachment 220059 [details] Example In the attached example there is a small example where a fixed positioned element is clipped with the clip-path property. It seems like the fixed positioned element is drawn on a graphics buffer and this buffer is not cleared. This leads to artifacts on areas that are clipped away. Reload the example multiple times to see the issue. In Safari stable the background is always black. In nightlies the background is not stable. It even happened that a video playing in another application show through. This just happens with "position: fixed".
Attachments
Example (396 bytes, text/html)
2013-12-27 07:07 PST, Dirk Schulze 		no flags
Details
Patch (3.75 KB, patch)
2014-02-17 11:02 PST, Simon Fraser (smfr) 		thorton: review+
DetailsFormatted DiffDiff
View All Add attachment proposed patch, testcase, etc.
Simon Fraser (smfr)
Comment 1 2013-12-30 11:15:43 PST
Hmm, we probably think it's opaque when it isn't.
Radar WebKit Bug Importer
Comment 2 2013-12-30 11:16:26 PST
<rdar://problem/15732905>
Simon Fraser (smfr)
Comment 3 2014-02-17 11:02:48 PST
Created attachment 224397 [details] Patch
Simon Fraser (smfr)
Comment 4 2014-02-17 11:08:29 PST
https://trac.webkit.org/r164232
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