Visit http://www.w3schools.com/cssref/css_selectors.asp and scroll down a bit. It triggers this assertion: ASSERTION FAILED: !isFullUpdate || !m_subframeScrollLayersNeedReattach ../../Source/WebCore/rendering/RenderLayerCompositor.cpp(749) : bool WebCore::RenderLayerCompositor::updateCompositingLayers(WebCore::CompositingUpdateType, WebCore::RenderLayer*) 1 0x7f159b6522d2 /home/mcatanzaro/Projects/GNOME/install/lib/libjavascriptcoregtk-4.0.so.18(WTFCrash+0x1e) [0x7f159b6522d2] 2 0x7f15a4ec357d /home/mcatanzaro/Projects/GNOME/install/lib/libwebkit2gtk-4.0.so.37(_ZN7WebCore21RenderLayerCompositor23updateCompositingLayersENS_21CompositingUpdateTypeEPNS_11RenderLayerE+0x6f9) [0x7f15a4ec357d] 3 0x7f15a4a4db50 /home/mcatanzaro/Projects/GNOME/install/lib/libwebkit2gtk-4.0.so.37(_ZN7WebCore9FrameView37updateCompositingLayersAfterScrollingEv+0xc4) [0x7f15a4a4db50] 4 0x7f15a4b4da83 /home/mcatanzaro/Projects/GNOME/install/lib/libwebkit2gtk-4.0.so.37(_ZN7WebCore10ScrollView28completeUpdatesAfterScrollToERKNS_7IntSizeE+0x55) [0x7f15a4b4da83] 5 0x7f15a4b4d9df /home/mcatanzaro/Projects/GNOME/install/lib/libwebkit2gtk-4.0.so.37(_ZN7WebCore10ScrollView8scrollToERKNS_8IntPointE+0x2a1) [0x7f15a4b4d9df] 6 0x7f15a4a51dbc /home/mcatanzaro/Projects/GNOME/install/lib/libwebkit2gtk-4.0.so.37(_ZN7WebCore9FrameView8scrollToERKNS_8IntPointE+0x40) [0x7f15a4a51dbc] 7 0x7f15a4b4d48b /home/mcatanzaro/Projects/GNOME/install/lib/libwebkit2gtk-4.0.so.37(_ZN7WebCore10ScrollView15setScrollOffsetERKNS_8IntPointE+0x17f) [0x7f15a4b4d48b] 8 0x7f15a4b56028 /home/mcatanzaro/Projects/GNOME/install/lib/libwebkit2gtk-4.0.so.37(_ZN7WebCore14ScrollableArea21scrollPositionChangedERKNS_8IntPointE+0x82) [0x7f15a4b56028] 9 0x7f15a4b56390 /home/mcatanzaro/Projects/GNOME/install/lib/libwebkit2gtk-4.0.so.37(_ZN7WebCore14ScrollableArea28setScrollOffsetFromAnimationERKNS_8IntPointE+0x58) [0x7f15a4b56390] 10 0x7f15a4b4bb09 /home/mcatanzaro/Projects/GNOME/install/lib/libwebkit2gtk-4.0.so.37(_ZN7WebCore14ScrollAnimator21notifyPositionChangedERKNS_9FloatSizeE+0x55) [0x7f15a4b4bb09] 11 0x7f15a4b4b5bf /home/mcatanzaro/Projects/GNOME/install/lib/libwebkit2gtk-4.0.so.37(_ZN7WebCore14ScrollAnimator6scrollENS_20ScrollbarOrientationENS_17ScrollGranularityEff+0x1d5) [0x7f15a4b4b5bf] 12 0x7f15a545e72e /home/mcatanzaro/Projects/GNOME/install/lib/libwebkit2gtk-4.0.so.37(_ZN7WebCore17ScrollAnimatorGtk6scrollENS_20ScrollbarOrientationENS_17ScrollGranularityEff+0x84) [0x7f15a545e72e] 13 0x7f15a4b4b98b /home/mcatanzaro/Projects/GNOME/install/lib/libwebkit2gtk-4.0.so.37(_ZN7WebCore14ScrollAnimator16handleWheelEventERKNS_18PlatformWheelEventE+0x2f9) [0x7f15a4b4b98b] 14 0x7f15a4b562d5 /home/mcatanzaro/Projects/GNOME/install/lib/libwebkit2gtk-4.0.so.37(_ZN7WebCore14ScrollableArea16handleWheelEventERKNS_18PlatformWheelEventE+0x59) [0x7f15a4b562d5] 15 0x7f15a4a56532 /home/mcatanzaro/Projects/GNOME/install/lib/libwebkit2gtk-4.0.so.37(_ZN7WebCore9FrameView10wheelEventERKNS_18PlatformWheelEventE+0x16a) [0x7f15a4a56532] 16 0x7f15a4a20d50 /home/mcatanzaro/Projects/GNOME/install/lib/libwebkit2gtk-4.0.so.37(_ZN7WebCore12EventHandler26platformCompleteWheelEventERKNS_18PlatformWheelEventEPNS_13ContainerNodeERKN3WTF7WeakPtrINS_14ScrollableAreaEEE+0x5c) [0x7f15a4a20d50] 17 0x7f15a4a2150b /home/mcatanzaro/Projects/GNOME/install/lib/libwebkit2gtk-4.0.so.37(_ZN7WebCore12EventHandler16handleWheelEventERKNS_18PlatformWheelEventE+0x547) [0x7f15a4a2150b] 18 0x7f15a50915f0 /home/mcatanzaro/Projects/GNOME/install/lib/libwebkit2gtk-4.0.so.37(_ZN7WebCore15UserInputBridge16handleWheelEventERKNS_18PlatformWheelEventENS_11InputSourceE+0x3c) [0x7f15a50915f0] 19 0x7f15a398653a /home/mcatanzaro/Projects/GNOME/install/lib/libwebkit2gtk-4.0.so.37(+0x538353a) [0x7f15a398653a] 20 0x7f15a39865c6 /home/mcatanzaro/Projects/GNOME/install/lib/libwebkit2gtk-4.0.so.37(_ZN6WebKit7WebPage10wheelEventERKNS_13WebWheelEventE+0x58) [0x7f15a39865c6] 21 0x7f15a395d30d /home/mcatanzaro/Projects/GNOME/install/lib/libwebkit2gtk-4.0.so.37(_ZN6WebKit15EventDispatcher18dispatchWheelEventEmRKNS_13WebWheelEventE+0x79) [0x7f15a395d30d] 22 0x7f15a395d107 /home/mcatanzaro/Projects/GNOME/install/lib/libwebkit2gtk-4.0.so.37(+0x535a107) [0x7f15a395d107] 23 0x7f15a395da16 /home/mcatanzaro/Projects/GNOME/install/lib/libwebkit2gtk-4.0.so.37(+0x535aa16) [0x7f15a395da16] 24 0x7f15a352d56d /home/mcatanzaro/Projects/GNOME/install/lib/libwebkit2gtk-4.0.so.37(_ZNK3WTF8FunctionIFvvEEclEv+0x37) [0x7f15a352d56d] 25 0x7f159b671a68 /home/mcatanzaro/Projects/GNOME/install/lib/libjavascriptcoregtk-4.0.so.18(_ZN3WTF7RunLoop11performWorkEv+0xce) [0x7f159b671a68] 26 0x7f159b6b88e8 /home/mcatanzaro/Projects/GNOME/install/lib/libjavascriptcoregtk-4.0.so.18(+0x25008e8) [0x7f159b6b88e8] 27 0x7f159b6b890c /home/mcatanzaro/Projects/GNOME/install/lib/libjavascriptcoregtk-4.0.so.18(+0x250090c) [0x7f159b6b890c] 28 0x7f159b6b8888 /home/mcatanzaro/Projects/GNOME/install/lib/libjavascriptcoregtk-4.0.so.18(+0x2500888) [0x7f159b6b8888] 29 0x7f159b6b88b7 /home/mcatanzaro/Projects/GNOME/install/lib/libjavascriptcoregtk-4.0.so.18(+0x25008b7) [0x7f159b6b88b7] 30 0x7f159399e2de /home/mcatanzaro/Projects/GNOME/install/lib/libglib-2.0.so.0(+0x542de) [0x7f159399e2de] 31 0x7f159399f160 /home/mcatanzaro/Projects/GNOME/install/lib/libglib-2.0.so.0(g_main_context_dispatch+0x33) [0x7f159399f160]
I saw the same assertion failure while using MiniBrowser of WinCairo port (Debug buld, trunk@217917) in some web sites today. Callstack: > WTF.dll!WTFCrash() Line 292 C++ > WebKit.dll!WebCore::RenderLayerCompositor::updateCompositingLayers(WebCore::CompositingUpdateType updateType, WebCore::RenderLayer * updateRoot) Line 752 C++ > WebKit.dll!WebCore::FrameView::updateCompositingLayersAfterScrolling() Line 2665 C++ > WebKit.dll!WebCore::ScrollView::completeUpdatesAfterScrollTo(const WebCore::IntSize & scrollDelta) Line 482 C++ > WebKit.dll!WebCore::ScrollView::scrollTo(const WebCore::IntPoint & newPosition) Line 475 C++ > WebKit.dll!WebCore::FrameView::scrollTo(const WebCore::IntPoint & newPosition) Line 3899 C++ > WebKit.dll!WebCore::ScrollView::setScrollOffset(const WebCore::IntPoint & offset) Line 414 C++ > WebKit.dll!WebCore::ScrollableArea::scrollPositionChanged(const WebCore::IntPoint & position) Line 171 C++ > WebKit.dll!WebCore::ScrollableArea::setScrollOffsetFromAnimation(const WebCore::IntPoint & offset) Line 233 C++ > WebKit.dll!WebCore::ScrollAnimator::notifyPositionChanged(const WebCore::FloatSize & delta) Line 196 C++ > WebKit.dll!WebCore::ScrollAnimator::scroll(WebCore::ScrollbarOrientation orientation, WebCore::ScrollGranularity __formal, float step, float multiplier) Line 77 C++ > WebKit.dll!WebCore::ScrollAnimator::handleWheelEvent(const WebCore::PlatformWheelEvent & e) Line 153 C++ > WebKit.dll!WebCore::ScrollableArea::handleWheelEvent(const WebCore::PlatformWheelEvent & wheelEvent) Line 203 C++ > WebKit.dll!WebCore::FrameView::wheelEvent(const WebCore::PlatformWheelEvent & wheelEvent) Line 5060 C++ > WebKit.dll!WebCore::EventHandler::platformCompleteWheelEvent(const WebCore::PlatformWheelEvent & event, WebCore::ContainerNode * __formal, const WTF::WeakPtr<WebCore::ScrollableArea> & __formal) Line 2642 C++ > WebKit.dll!WebCore::EventHandler::handleWheelEvent(const WebCore::PlatformWheelEvent & event) Line 2777 C++ > WebKit.dll!WebView::mouseWheel(unsigned __int64 wParam, __int64 lParam, bool isMouseHWheel) Line 2136 C++ > WebKit.dll!WebView::WebViewWndProc(HWND__ * hWnd, unsigned int message, unsigned __int64 wParam, __int64 lParam) Line 2613 C++ > [External Code] > WebKit.dll!WebKitMessageLoop::run(HACCEL__ * hAccelTable) Line 97 C++ > MiniBrowserLib.dll!wWinMain(HINSTANCE__ * hInstance, HINSTANCE__ * hPrevInstance, wchar_t * lpstrCmdLine, int nCmdShow) Line 189 C++ > MiniBrowserLib.dll!dllLauncherEntryPoint(HINSTANCE__ * hInstance, HINSTANCE__ * hPrevInstance, wchar_t * lpstrCmdLine, int nCmdShow) Line 857 C++ > MiniBrowser.exe!wWinMain(HINSTANCE__ * hInstance, HINSTANCE__ * hPrevInstance, wchar_t * lpstrCmdLine, int nCmdShow) Line 249 C++ > [External Code]