Found with mozilla-central changeset: 406904:493e45400842 mozilla-central/layout/painting/nsCSSRendering.cpp:3054:57: runtime error: division by zero #0 0x7fa4943a7921 in nsCSSRendering::ComputeRoundedSize(int, int) mozilla-central/layout/painting/nsCSSRendering.cpp:3054:57 #1 0x7fa494436886 in ComputeTile(nsRect&, mozilla::StyleBorderImageRepeat, mozilla::StyleBorderImageRepeat, nsSize const&, nsSize&) mozilla-central/layout/painting/nsImageRenderer.cpp:772:18 #2 0x7fa4944366fc in mozilla::nsImageRenderer::DrawBorderImageComponent(nsPresContext*, gfxContext&, nsRect const&, nsRect const&, mozilla::gfx::IntRectTyped<mozilla::CSSPixel> const&, mozilla::StyleBorderImageRepeat, mozilla::StyleBorderImageRepeat, nsSize const&, unsigned char, mozilla::Maybe<nsSize> const&, bool) mozilla-central/layout/painting/nsImageRenderer.cpp:944:21 #3 0x7fa49439bfbf in nsCSSBorderImageRenderer::DrawBorderImage(nsPresContext*, gfxContext&, nsIFrame*, nsRect const&) mozilla-central/layout/painting/nsCSSRenderingBorders.cpp:3660:24 #4 0x7fa4943986e0 in nsCSSRendering::PaintBorderWithStyleBorder(nsPresContext*, gfxContext&, nsIFrame*, nsRect const&, nsRect const&, nsStyleBorder const&, nsStyleContext*, mozilla::PaintBorderFlags, mozilla::Sides) mozilla-central/layout/painting/nsCSSRendering.cpp:936:24 #5 0x7fa49439853b in nsCSSRendering::PaintBorder(nsPresContext*, gfxContext&, nsIFrame*, nsRect const&, nsRect const&, nsStyleContext*, mozilla::PaintBorderFlags, mozilla::Sides) mozilla-central/layout/painting/nsCSSRendering.cpp:648:12 #6 0x7fa4943dba6d in nsDisplayBorder::Paint(nsDisplayListBuilder*, gfxContext*) mozilla-central/layout/painting/nsDisplayList.cpp:5774:5 #7 0x7fa494391cfb in mozilla::FrameLayerBuilder::PaintItems(nsTArray<mozilla::AssignedDisplayItem>&, mozilla::gfx::IntRectTyped<mozilla::gfx::UnknownUnits> const&, gfxContext*, nsDisplayListBuilder*, nsPresContext*, mozilla::gfx::IntPointTyped<mozilla::gfx::UnknownUnits> const&, float, float, int) mozilla-central/layout/painting/FrameLayerBuilder.cpp:6109:21 #8 0x7fa49439268c in mozilla::FrameLayerBuilder::DrawPaintedLayer(mozilla::layers::PaintedLayer*, gfxContext*, mozilla::gfx::IntRegionTyped<mozilla::gfx::UnknownUnits> const&, mozilla::gfx::IntRegionTyped<mozilla::gfx::UnknownUnits> const&, mozilla::layers::DrawRegionClip, mozilla::gfx::IntRegionTyped<mozilla::gfx::UnknownUnits> const&, void*) mozilla-central/layout/painting/FrameLayerBuilder.cpp:6266:19 #9 0x7fa491911b3e in mozilla::layers::ClientPaintedLayer::PaintThebes(nsTArray<mozilla::layers::ReadbackProcessor::Update>*) mozilla-central/gfx/layers/client/ClientPaintedLayer.cpp:158:5 #10 0x7fa491912766 in mozilla::layers::ClientPaintedLayer::RenderLayerWithReadback(mozilla::layers::ReadbackProcessor*) mozilla-central/gfx/layers/client/ClientPaintedLayer.cpp:314:3 #11 0x7fa49192d4d5 in mozilla::layers::ClientContainerLayer::RenderLayer() mozilla-central/gfx/layers/client/ClientContainerLayer.h:58:29 #12 0x7fa49190f272 in mozilla::layers::ClientLayerManager::EndTransactionInternal(void (*)(mozilla::layers::PaintedLayer*, gfxContext*, mozilla::gfx::IntRegionTyped<mozilla::gfx::UnknownUnits> const&, mozilla::gfx::IntRegionTyped<mozilla::gfx::UnknownUnits> const&, mozilla::layers::DrawRegionClip, mozilla::gfx::IntRegionTyped<mozilla::gfx::UnknownUnits> const&, void*), void*, mozilla::layers::LayerManager::EndTransactionFlags) mozilla-central/gfx/layers/client/ClientLayerManager.cpp:359:13 #13 0x7fa49190f7b4 in mozilla::layers::ClientLayerManager::EndTransaction(void (*)(mozilla::layers::PaintedLayer*, gfxContext*, mozilla::gfx::IntRegionTyped<mozilla::gfx::UnknownUnits> const&, mozilla::gfx::IntRegionTyped<mozilla::gfx::UnknownUnits> const&, mozilla::layers::DrawRegionClip, mozilla::gfx::IntRegionTyped<mozilla::gfx::UnknownUnits> const&, void*), void*, mozilla::layers::LayerManager::EndTransactionFlags) mozilla-central/gfx/layers/client/ClientLayerManager.cpp:423:3 #14 0x7fa4943caae9 in nsDisplayList::PaintRoot(nsDisplayListBuilder*, gfxContext*, unsigned int) mozilla-central/layout/painting/nsDisplayList.cpp:2779:19 #15 0x7fa493fbff6d in nsLayoutUtils::PaintFrame(gfxContext*, nsIFrame*, nsRegion const&, unsigned int, nsDisplayListBuilderMode, nsLayoutUtils::PaintFrameFlags) mozilla-central/layout/base/nsLayoutUtils.cpp:4016:12 #16 0x7fa493f3ea19 in mozilla::PresShell::Paint(nsView*, nsRegion const&, unsigned int) mozilla-central/layout/base/PresShell.cpp:6447:5 #17 0x7fa493b061d4 in nsViewManager::ProcessPendingUpdatesPaint(nsIWidget*) mozilla-central/view/nsViewManager.cpp:480:19 #18 0x7fa493b05bd7 in nsViewManager::ProcessPendingUpdatesForView(nsView*, bool) mozilla-central/view/nsViewManager.cpp:412:33 #19 0x7fa493b06f16 in nsViewManager::ProcessPendingUpdates() mozilla-central/view/nsViewManager.cpp:1102:5 #20 0x7fa493ef7909 in nsRefreshDriver::Tick(long, mozilla::TimeStamp) mozilla-central/layout/base/nsRefreshDriver.cpp:2063:11 #21 0x7fa493efdd19 in mozilla::RefreshDriverTimer::TickRefreshDrivers(long, mozilla::TimeStamp, nsTArray<RefPtr<nsRefreshDriver> >&) mozilla-central/layout/base/nsRefreshDriver.cpp:310:7 #22 0x7fa493efdb5c in mozilla::RefreshDriverTimer::Tick(long, mozilla::TimeStamp) mozilla-central/layout/base/nsRefreshDriver.cpp:332:5 #23 0x7fa493f00366 in mozilla::VsyncRefreshDriverTimer::RunRefreshDrivers(mozilla::TimeStamp) mozilla-central/layout/base/nsRefreshDriver.cpp:773:5 #24 0x7fa493eff90d in mozilla::VsyncRefreshDriverTimer::RefreshDriverVsyncObserver::TickRefreshDriver(mozilla::TimeStamp) mozilla-central/layout/base/nsRefreshDriver.cpp:686:35 #25 0x7fa493eff4c2 in mozilla::VsyncRefreshDriverTimer::RefreshDriverVsyncObserver::NotifyVsync(mozilla::TimeStamp) mozilla-central/layout/base/nsRefreshDriver.cpp:587:9 #26 0x7fa494322627 in mozilla::layout::VsyncChild::RecvNotify(mozilla::TimeStamp const&) mozilla-central/layout/ipc/VsyncChild.cpp:68:16 #27 0x7fa490e88965 in mozilla::layout::PVsyncChild::OnMessageReceived(IPC::Message const&) mozilla-central/objdir-ff-ubsan/ipc/ipdl/PVsyncChild.cpp:156:20 #28 0x7fa490b64efd in mozilla::ipc::MessageChannel::DispatchAsyncMessage(IPC::Message const&) mozilla-central/ipc/glue/MessageChannel.cpp:2133:25 #29 0x7fa490b636e3 in mozilla::ipc::MessageChannel::DispatchMessage(IPC::Message&&) mozilla-central/ipc/glue/MessageChannel.cpp:2063:17 #30 0x7fa490b64608 in mozilla::ipc::MessageChannel::MessageTask::Run() mozilla-central/ipc/glue/MessageChannel.cpp:1942:15 #31 0x7fa4900bb393 in nsThread::ProcessNextEvent(bool, bool*) mozilla-central/xpcom/threads/nsThread.cpp:1040:14 #32 0x7fa4900d7c60 in NS_ProcessNextEvent(nsIThread*, bool) mozilla-central/xpcom/threads/nsThreadUtils.cpp:517:10 #33 0x7fa490b68aab in mozilla::ipc::MessagePump::Run(base::MessagePump::Delegate*) mozilla-central/ipc/glue/MessagePump.cpp:97:21 #34 0x7fa490a8f679 in RunHandler mozilla-central/ipc/chromium/src/base/message_loop.cc:319:3 #35 0x7fa490a8f679 in MessageLoop::Run() mozilla-central/ipc/chromium/src/base/message_loop.cc:299 #36 0x7fa493b4f146 in nsBaseAppShell::Run() mozilla-central/widget/nsBaseAppShell.cpp:157:27 #37 0x7fa49715a614 in XRE_RunAppShell() mozilla-central/toolkit/xre/nsEmbedFunctions.cpp:892:22 #38 0x7fa490a8f679 in RunHandler mozilla-central/ipc/chromium/src/base/message_loop.cc:319:3 #39 0x7fa490a8f679 in MessageLoop::Run() mozilla-central/ipc/chromium/src/base/message_loop.cc:299 #40 0x7fa49715a240 in XRE_InitChildProcess(int, char**, XREChildData const*) mozilla-central/toolkit/xre/nsEmbedFunctions.cpp:718:34 #41 0x42d23b in content_process_main(mozilla::Bootstrap*, int, char**) mozilla-central/browser/app/../../ipc/contentproc/plugin-container.cpp:50:30 #42 0x42d358 in main mozilla-central/browser/app/nsBrowserApp.cpp:280:18 #43 0x7fa4b4aa61c0 in __libc_start_main /build/glibc-itYbWN/glibc-2.26/csu/../csu/libc-start.c:308 #44 0x407159 in _start (mozilla-central/objdir-ff-ubsan/dist/bin/firefox+0x407159)

Permalinks for the first several stack frames: https://searchfox.org/mozilla-central/rev/33cc9e0331da8d9ff3750f1e68d72d61201176cb/layout/painting/nsCSSRendering.cpp#3054 https://searchfox.org/mozilla-central/rev/33cc9e0331da8d9ff3750f1e68d72d61201176cb/layout/painting/nsImageRenderer.cpp#772 https://searchfox.org/mozilla-central/rev/33cc9e0331da8d9ff3750f1e68d72d61201176cb/layout/painting/nsImageRenderer.cpp#944 https://searchfox.org/mozilla-central/rev/33cc9e0331da8d9ff3750f1e68d72d61201176cb/layout/painting/nsCSSRenderingBorders.cpp#3660

I don't think this is related to stylo at all...