Flaky crash seen on this run with imported/w3c/csswg-test/css-scoping-1/shadow-cascade-order-001.html (crash is attributed to imported/w3c/web-platform-tests/html/semantics/embedded-content/media-elements/interfaces/TextTrack/activeCues.html in the results) https://build.webkit.org/results/Apple%20Sierra%20Release%20WK2%20(Tests)/r207571%20(773)/results.html Thread 0 Crashed:: Dispatch queue: com.apple.main-thread 0 com.apple.WebCore 0x0000000109c88d68 WebCore::RenderVTTCue::initializeLayoutParameters(WebCore::InlineFlowBox*&, WebCore::LayoutUnit&, WebCore::LayoutUnit&) + 88 (InlineBox.h:341) 1 com.apple.WebCore 0x0000000109c887d3 WebCore::RenderVTTCue::repositionCueSnapToLinesSet() + 51 (RenderVTTCue.cpp:314) 2 com.apple.WebCore 0x0000000109c88743 WebCore::RenderVTTCue::layout() + 291 (RenderView.h:417) 3 com.apple.WebCore 0x0000000109ad59e8 WebCore::RenderBlock::layoutPositionedObject(WebCore::RenderBox&, bool, bool) + 408 (RenderBlock.cpp:1483) 4 com.apple.WebCore 0x0000000109ad54e6 WebCore::RenderBlock::layoutPositionedObjects(bool, bool) + 182 (ListHashSet.h:84) 5 com.apple.WebCore 0x0000000109ae922d WebCore::RenderBlockFlow::layoutBlock(bool, WebCore::LayoutUnit) + 1949 (RenderBlockFlow.cpp:529) 6 com.apple.WebCore 0x0000000109ad3dc6 WebCore::RenderBlock::layout() + 54 (RenderBlock.cpp:994) 7 com.apple.WebCore 0x0000000109c809b1 WebCore::RenderView::layout() + 785 (memory:2710) 8 com.apple.WebCore 0x00000001092ae878 WebCore::FrameView::layout(bool) + 2824 (Ref.h:142) 9 com.apple.WebCore 0x00000001092b6bb7 WebCore::FrameView::updateLayoutAndStyleIfNeededRecursive() + 167 (FrameView.cpp:4288) 10 com.apple.WebKit 0x000000010504cdc1 WebKit::TiledCoreAnimationDrawingArea::flushLayers() + 45 (TiledCoreAnimationDrawingArea.mm:406) 11 com.apple.WebCore 0x0000000109962ffc WebCore::LayerFlushScheduler::layerFlushCallback() + 28 (LayerFlushSchedulerMac.cpp:77) 12 com.apple.CoreFoundation 0x7fff7b6b6f87 __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 23 (/Library/Caches/com.apple.xbs/Sources/CF/CF-1348.1/RunLoop.subproj/CFRunLoop.c:1802) 13 com.apple.CoreFoundation 0x7fff7b6b6ef7 __CFRunLoopDoObservers + 391 (/Library/Caches/com.apple.xbs/Sources/CF/CF-1348.1/RunLoop.subproj/CFRunLoop.c:1898) 14 com.apple.CoreFoundation 0x7fff7b697896 CFRunLoopRunSpecific + 454 (/Library/Caches/com.apple.xbs/Sources/CF/CF-1348.1/RunLoop.subproj/CFRunLoop.c:3114) 15 com.apple.HIToolbox 0x7fff7ac37f6c RunCurrentEventLoopInMode + 240 (Events/EventsCore/EventLoop.c:440) 16 com.apple.HIToolbox 0x7fff7ac37da1 ReceiveNextEventCommon + 432 (/BuildRoot/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.Internal.sdk/usr/include/dispatch/once.h:77) 17 com.apple.HIToolbox 0x7fff7ac37bd6 _BlockUntilNextEventMatchingListInModeWithFilter + 71 (Events/EventsCore/EventBlocking.c:161) 18 com.apple.AppKit 0x7fff7932e5f5 _DPSNextEvent + 1093 (/Library/Caches/com.apple.xbs/Sources/AppKit/AppKit-1504/GraphicsContext.subproj/CGDPSReplacement.m:710) 19 com.apple.AppKit 0x7fff79a3e8eb -[NSApplication(NSEvent) _nextEventMatchingEventMask:untilDate:inMode:dequeue:] + 1637 (/Library/Caches/com.apple.xbs/Sources/AppKit/AppKit-1504/Events.subproj/appEventRouting.m:1306) 20 com.apple.AppKit 0x7fff79322fbd -[NSApplication run] + 926 (/Library/Caches/com.apple.xbs/Sources/AppKit/AppKit-1504/AppKit.subproj/NSApplication.m:3651) 21 com.apple.AppKit 0x7fff792eda8a NSApplicationMain + 1237 (/Library/Caches/com.apple.xbs/Sources/AppKit/AppKit-1504/AppKit.subproj/NSApplication.m:8995) 22 libxpc.dylib 0x7fff909cc8b3 _xpc_objc_main + 775 (/BuildRoot/Library/Caches/com.apple.xbs/Sources/libxpc/libxpc-972.1.5/src/main.m:162) 23 libxpc.dylib 0x7fff909cb2d0 xpc_main + 494 (/BuildRoot/Library/Caches/com.apple.xbs/Sources/libxpc/libxpc-972.1.5/src/init.c:1447) 24 com.apple.WebKit.WebContent 0x0000000104f0f7a2 main + 380 25 libdyld.dylib 0x00007fff90769255 start + 1
This may actually be the same as https://bugs.webkit.org/show_bug.cgi?id=163585
*** This bug has been marked as a duplicate of bug 163585 ***