Layers can have no backing store but still either have background-color, or even be totally empty, and they should still hit-test over a scroller.
Created attachment 363791 [details] Testcase
<rdar://problem/48652078>
Created attachment 365026 [details] patch
Created attachment 365028 [details] patch
Comment on attachment 365028 [details] patch View in context: https://bugs.webkit.org/attachment.cgi?id=365028&action=review r- to fix the pointer-events toggle issue (if it happens to work, please add a test). Don't forget you can use immediateScrollElementAtContentPointToOffset now). > Source/WebCore/rendering/RenderLayerBacking.cpp:768 > + updateEventRegion(); Here you're assuming that a layer configuration update will always happen when something changes that affects where renderers are relative to their enclosing compositing layer. This assumption relies on the fact that RenderLayerBacking::setContentsNeedDisplay() calls setNeedsCompositingConfigurationUpdate(), but if future optimizations allow us to update layer configuration in fewer cases, that might break. In fact, this might break now with something like: <div class="composited"><div id="child"></div> and dynamic toggle of "pointer-events" style on child. That won't issue a repaint (hopefully) and won't update event regions. You should also add a testcase that just moves elements around and tests event regions, so we can detect regressions caused by future compositing optimizations.
https://bugs.webkit.org/show_bug.cgi?id=195902 for pointe-events issue
Comment on attachment 365028 [details] patch Clearing flags on attachment: 365028 Committed r243092: <https://trac.webkit.org/changeset/243092>
All reviewed patches have been landed. Closing bug.
This change broke the Windows build: c:\cygwin\home\buildbot\worker\win10-release\build\source\webcore\rendering\renderlayerbacking.cpp(1437): error C2668: 'WebCore::GraphicsContext::GraphicsContext': ambiguous call to overloaded function (compiling source file C:\cygwin\home\buildbot\worker\win10-release\build\WebKitBuild\Release\DerivedSources\WebCore\unified-sources\UnifiedSource-043dd90b-8.cpp) [C:\cygwin\home\buildbot\worker\win10-release\build\WebKitBuild\Release\Source\WebCore\WebCore.vcxproj] c:\cygwin\home\buildbot\worker\win10-release\build\source\webcore\platform\graphics\graphicscontext.h(266): note: could be 'WebCore::GraphicsContext::GraphicsContext(PlatformGraphicsContext *)' (compiling source file C:\cygwin\home\buildbot\worker\win10-release\build\WebKitBuild\Release\DerivedSources\WebCore\unified-sources\UnifiedSource-043dd90b-8.cpp) c:\cygwin\home\buildbot\worker\win10-release\build\source\webcore\platform\graphics\graphicscontext.h(522): note: or 'WebCore::GraphicsContext::GraphicsContext(HDC,bool)' (compiling source file C:\cygwin\home\buildbot\worker\win10-release\build\WebKitBuild\Release\DerivedSources\WebCore\unified-sources\UnifiedSource-043dd90b-8.cpp) c:\cygwin\home\buildbot\worker\win10-release\build\source\webcore\rendering\renderlayerbacking.cpp(1437): note: while trying to match the argument list '(nullptr)' (compiling source file C:\cygwin\home\buildbot\worker\win10-release\build\WebKitBuild\Release\DerivedSources\WebCore\unified-sources\UnifiedSource-043dd90b-8.cpp) https://build.webkit.org/builders/Apple%20Win%2010%20Release%20%28Build%29/builds/2965
Windows build fix https://trac.webkit.org/changeset/243096/webkit
Re-opened since this is blocked by bug 195926
This cause assertions like: ASSERTION FAILED: clipRectsContext.rootLayer == m_clipRectsCache->m_clipRectsRoot[clipRectsType] 0 com.apple.JavaScriptCore 0x000000070f1be55e WTFCrash + 14 (Assertions.cpp:305) 1 com.apple.WebCore 0x00000006f84d14eb WTFCrashWithInfo(int, char const*, char const*, int) + 27 2 com.apple.WebCore 0x00000006fbba5629 WebCore::RenderLayer::updateClipRects(WebCore::RenderLayer::ClipRectsContext const&) + 345 (RenderLayer.cpp:5349) 3 com.apple.WebCore 0x00000006fbba6acf WebCore::RenderLayer::parentClipRects(WebCore::RenderLayer::ClipRectsContext const&) const + 255 4 com.apple.WebCore 0x00000006fbba6bbf WebCore::RenderLayer::backgroundClipRect(WebCore::RenderLayer::ClipRectsContext const&) const::$_1::operator()() const + 223 (RenderLayer.cpp:5499) 5 com.apple.WebCore 0x00000006fbb9a77e WebCore::RenderLayer::backgroundClipRect(WebCore::RenderLayer::ClipRectsContext const&) const + 158 (RenderLayer.cpp:5507) 6 com.apple.WebCore 0x00000006fbba10b0 WebCore::RenderLayer::calculateRects(WebCore::RenderLayer::ClipRectsContext const&, WebCore::LayoutRect const&, WebCore::LayoutRect&, WebCore::ClipRect&, WebCore::ClipRect&, WebCore::LayoutSize const&) const + 112 (RenderLayer.cpp:5519) 7 com.apple.WebCore 0x00000006fbb9ec0f WebCore::RenderLayer::collectFragments(WTF::Vector<WebCore::LayerFragment, 1ul, WTF::CrashOnOverflow, 16ul>&, WebCore::RenderLayer const*, WebCore::LayoutRect const&, WebCore::RenderLayer::PaginationInclusionMode, WebCore::ClipRectsType, WebCore::OverlayScrollbarSizeRelevancy, WebCore::ShouldRespectOverflowClip, WebCore::LayoutSize const&, WebCore::LayoutRect const*, WebCore::ShouldApplyRootOffsetToFragments) + 303 (RenderLayer.cpp:4516) 8 com.apple.WebCore 0x00000006fbb9ba05 WebCore::RenderLayer::paintLayerContents(WebCore::GraphicsContext&, WebCore::RenderLayer::LayerPaintingInfo const&, WTF::OptionSet<WebCore::RenderLayer::PaintLayerFlag>) + 2885 (RenderLayer.cpp:4339) because the paint triggered by RenderLayerBacking::updateEventRegion() caches the wrong clip rect roots. Also, why are we paying the cost for this event region computation on macOS?
compositing/repaint/requires-backing-repaint.html is a test that hit this assertion, on macOS.
Created attachment 365138 [details] patch Don't collect the region for layers that have paintsIntoCompositedAncestor() set.
Comment on attachment 365138 [details] patch Clearing flags on attachment: 365138 Committed r243134: <https://trac.webkit.org/changeset/243134>