haikuwebkit

nephele

msn.com: Header flickers when scrolling articles https://bugs.webkit.org/show_bug.cgi?id=211126 <rdar://problem/56439177> Reviewed by Simon Fraser. Source/WebCore: Test: compositing/fixed-with-clip-stability.html In case of fixed positioned elements the decision to create backing depends on clip rect. However RenderLayer::localClipRect() tests for backing in call to clippingRootForPainting(). This creates instability since clipping depends on backing decision, and backing decision depends on clipping. * rendering/RenderLayer.cpp: (WebCore::RenderLayer::localClipRect const): Specifically the result of clipExceedsBounds test here is affected by computed offsetFromRoot: "clipRect.contains(cssClipRect)" test fails for zero sized clips with different offsets. Compute clipExceedsBounds by looking at the clip sizes only and ignoring the position (which should match). LayoutTests: * compositing/fixed-with-clip-stability-expected.txt: Added. * compositing/fixed-with-clip-stability.html: Added. Canonical link: https://commits.webkit.org/224023@main git-svn-id: https://svn.webkit.org/repository/webkit/trunk@260828 268f45cc-cd09-0410-ab3c-d52691b4dbfc 2020-04-28 16:05:36 +00:00			`text`
			`PASS`