Bug 76329 - Unmatched transparency layer begin/end on a filtered element with an opacity ancestor
Summary: Unmatched transparency layer begin/end on a filtered element with an opacity ...
Alias: None
Product: WebKit
Classification: Unclassified
Component: Layout and Rendering (show other bugs)
Version: 528+ (Nightly build)
Hardware: Unspecified Unspecified
: P2 Normal
Assignee: Simon Fraser (smfr)
Keywords: InRadar
Depends on:
Reported: 2012-01-13 19:10 PST by Simon Fraser (smfr)
Modified: 2012-01-16 00:29 PST (History)
3 users (show)

See Also:

Testcase (561 bytes, text/html)
2012-01-13 19:10 PST, Simon Fraser (smfr)
no flags Details
Patch (4.08 KB, patch)
2012-01-13 19:33 PST, Simon Fraser (smfr)
mitz: review+
Details | Formatted Diff | Diff

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Description Simon Fraser (smfr) 2012-01-13 19:10:47 PST
Created attachment 122531 [details]

The attached test case hits ASSERTION FAILED: m_transparencyCount > 0 when painting, if the context has paintingDisabled() (e.g. when doing a Find in Safari).
Comment 1 Simon Fraser (smfr) 2012-01-13 19:15:35 PST
The issue is that RenderLayer::beginTransparencyLayers() bails if context->paintingDisabled() is true, so never starting the transparency layer. However, when rendering the child, filterPainter hands back a context with painting enabled. We then hit beginTransparencyLayers() in the if (localPaintFlags & PaintLayerPaintingCompositingForegroundPhase) clause, since haveTransparency was passed in from the ancestor.

We should just not apply filters if the context has painting disabled.
Comment 2 Simon Fraser (smfr) 2012-01-13 19:33:22 PST
Created attachment 122533 [details]
Comment 3 Radar WebKit Bug Importer 2012-01-13 19:34:38 PST
Comment 4 mitz 2012-01-13 19:58:49 PST
Comment on attachment 122533 [details]

View in context: https://bugs.webkit.org/attachment.cgi?id=122533&action=review

> Source/WebCore/ChangeLog:14
> +        Manual test:
> +            ManualTests/filters/opacity-above-filter.html

Could this be a TestWebKitAPI test instead?
Comment 5 Simon Fraser (smfr) 2012-01-14 07:52:16 PST
Comment 6 Alexandru Chiculita 2012-01-16 00:29:52 PST
(In reply to comment #5)
> http://trac.webkit.org/changeset/105019