Bug 172892

By opening a YouTube video in MiniBrowser and clicking around a few times on the time slider to make the video seek back and froward on a freshly built r217751/f36e82528540b debug build I was able to trigger the assertion below on a Debian sid machine: $ cd ~/dev/WebKit/ $ cmake . -DCMAKE_BUILD_TYPE=Debug -DPORT=GTK -DENABLE_SPELLCHECK=OFF -DENABLE_ACCELERATED_2D_CANVAS=OFF -DENABLE_GLES2=ON -DENABLE_PLUGIN_PROCESS_GTK2=OFF -DENABLE_TOOLS=ON -DENABLE_MINIBROWSER=ON -DDEVELOPER_MODE=ON $ make -j16 $ ./bin/MiniBrowser https://www.youtube.com/watch?v=U9t-slLl30E SHOULD NEVER BE REACHED Shared/CoordinatedGraphics/threadedcompositor/CompositingRunLoop.cpp(179) : void WebKit::CompositingRunLoop::updateCompleted() 1 0x7fd650c4a869 /home/user/dev/WebKit/lib/libjavascriptcoregtk-4.0.so.18(WTFCrash+0x1e) [0x7fd650c4a869] 2 0x7fd6593db3a4 /home/user/dev/WebKit/lib/libwebkit2gtk-4.0.so.37(_ZN6WebKit18CompositingRunLoop15updateCompletedEv+0x92) [0x7fd6593db3a4] 3 0x7fd6593e04cc /home/user/dev/WebKit/lib/libwebkit2gtk-4.0.so.37(_ZN6WebKit18ThreadedCompositor19sceneUpdateFinishedEv+0xb8) [0x7fd6593e04cc] 4 0x7fd6593e09f1 /home/user/dev/WebKit/lib/libwebkit2gtk-4.0.so.37(_ZN6WebKit18ThreadedCompositor13frameCompleteEv+0x45) [0x7fd6593e09f1] 5 0x7fd6595aeba4 /home/user/dev/WebKit/lib/libwebkit2gtk-4.0.so.37(_ZN6WebKit32ThreadedCoordinatedLayerTreeHost13frameCompleteEv+0x26) [0x7fd6595aeba4] 6 0x7fd6595b5e2f /home/user/dev/WebKit/lib/libwebkit2gtk-4.0.so.37(_ZN6WebKit21AcceleratedSurfaceX1114didRenderFrameEv+0x27) [0x7fd6595b5e2f] 7 0x7fd6595aecf3 /home/user/dev/WebKit/lib/libwebkit2gtk-4.0.so.37(_ZN6WebKit32ThreadedCoordinatedLayerTreeHost14didRenderFrameEv+0x43) [0x7fd6595aecf3] 8 0x7fd6595af91c /home/user/dev/WebKit/lib/libwebkit2gtk-4.0.so.37(_ZN6WebKit32ThreadedCoordinatedLayerTreeHost16CompositorClient14didRenderFrameEv+0x1c) [0x7fd6595af91c] 9 0x7fd6593e0404 /home/user/dev/WebKit/lib/libwebkit2gtk-4.0.so.37(_ZN6WebKit18ThreadedCompositor15renderLayerTreeEv+0x34e) [0x7fd6593e0404] 10 0x7fd6593df341 /home/user/dev/WebKit/lib/libwebkit2gtk-4.0.so.37(+0x5825341) [0x7fd6593df341] 11 0x7fd6593e2cb8 /home/user/dev/WebKit/lib/libwebkit2gtk-4.0.so.37(+0x5828cb8) [0x7fd6593e2cb8] 12 0x55a571e96ea8 /home/user/dev/WebKit/bin/WebKitWebProcess(_ZNKSt8functionIFvvEEclEv+0x32) [0x55a571e96ea8] 13 0x7fd6593db3c4 /home/user/dev/WebKit/lib/libwebkit2gtk-4.0.so.37(_ZN6WebKit18CompositingRunLoop16updateTimerFiredEv+0x1c) [0x7fd6593db3c4] 14 0x7fd6593de91c /home/user/dev/WebKit/lib/libwebkit2gtk-4.0.so.37(_ZN3WTF7RunLoop5TimerIN6WebKit18CompositingRunLoopEE5firedEv+0x66) [0x7fd6593de91c] 15 0x7fd650caf483 /home/user/dev/WebKit/lib/libjavascriptcoregtk-4.0.so.18(+0x2632483) [0x7fd650caf483] 16 0x7fd650caf4bf /home/user/dev/WebKit/lib/libjavascriptcoregtk-4.0.so.18(+0x26324bf) [0x7fd650caf4bf] 17 0x7fd650caebfe /home/user/dev/WebKit/lib/libjavascriptcoregtk-4.0.so.18(+0x2631bfe) [0x7fd650caebfe] 18 0x7fd650caec2d /home/user/dev/WebKit/lib/libjavascriptcoregtk-4.0.so.18(+0x2631c2d) [0x7fd650caec2d] 19 0x7fd64ae8e6aa /lib/x86_64-linux-gnu/libglib-2.0.so.0(g_main_context_dispatch+0x15a) [0x7fd64ae8e6aa] 20 0x7fd64ae8ea60 /lib/x86_64-linux-gnu/libglib-2.0.so.0(+0x4aa60) [0x7fd64ae8ea60] 21 0x7fd64ae8ed82 /lib/x86_64-linux-gnu/libglib-2.0.so.0(g_main_loop_run+0xc2) [0x7fd64ae8ed82] 22 0x7fd650caf14b /home/user/dev/WebKit/lib/libjavascriptcoregtk-4.0.so.18(_ZN3WTF7RunLoop3runEv+0xab) [0x7fd650caf14b] 23 0x7fd650cad403 /home/user/dev/WebKit/lib/libjavascriptcoregtk-4.0.so.18(+0x2630403) [0x7fd650cad403] 24 0x7fd650cad952 /home/user/dev/WebKit/lib/libjavascriptcoregtk-4.0.so.18(+0x2630952) [0x7fd650cad952] 25 0x55a571e96ea8 /home/user/dev/WebKit/bin/WebKitWebProcess(_ZNKSt8functionIFvvEEclEv+0x32) [0x55a571e96ea8] 26 0x7fd650c6d3ac /home/user/dev/WebKit/lib/libjavascriptcoregtk-4.0.so.18(+0x25f03ac) [0x7fd650c6d3ac] 27 0x7fd650cabab6 /home/user/dev/WebKit/lib/libjavascriptcoregtk-4.0.so.18(+0x262eab6) [0x7fd650cabab6] 28 0x7fd646dda494 /lib/x86_64-linux-gnu/libpthread.so.0(+0x7494) [0x7fd646dda494] 29 0x7fd645a41aff /lib/x86_64-linux-gnu/libc.so.6(clone+0x3f) [0x7fd645a41aff] I've not investigated it any further.