Not sure if this should go under SVG or Layout. Reduced with m-c: BuildID=20180608095612 SourceStamp=e0595117ff5bda3a63a72ad7b3b8754fec4fb4f0 Assertion failure: false (should have already reflowed the anonymous block child), at src/layout/svg/SVGTextFrame.cpp:425 #0 FrameIfAnonymousChildReflowed(SVGTextFrame*) src/layout/svg/SVGTextFrame.cpp:422:3 #1 mozilla::TextRenderedRunIterator::TextRenderedRunIterator(SVGTextFrame*, mozilla::TextRenderedRunIterator::RenderedRunFilter, nsIFrame*) src/layout/svg/SVGTextFrame.cpp:1877:22 #2 SVGTextFrame::TransformFrameRectFromTextChild(nsRect const&, nsIFrame*) src/layout/svg/SVGTextFrame.cpp:5757:27 #3 nsLayoutUtils::TransformFrameRectToAncestor(nsIFrame*, nsRect const&, nsIFrame const*, bool*, mozilla::Maybe<mozilla::gfx::Matrix4x4TypedFlagged<mozilla::gfx::UnknownUnits, mozilla::gfx::UnknownUnits> >*, bool, nsIFrame**) src/layout/base/nsLayoutUtils.cpp:2969:27 #4 ProcessFrameInternal(nsIFrame*, nsDisplayListBuilder&, AnimatedGeometryRoot**, nsRect&, nsIFrame*, nsTArray<nsIFrame*>&, bool) src/layout/painting/RetainedDisplayListBuilder.cpp:748:17 #5 RetainedDisplayListBuilder::ProcessFrame(nsIFrame*, nsDisplayListBuilder&, nsIFrame*, nsTArray<nsIFrame*>&, bool, nsRect*, AnimatedGeometryRoot**) src/layout/painting/RetainedDisplayListBuilder.cpp:899:3 #6 RetainedDisplayListBuilder::ComputeRebuildRegion(nsTArray<nsIFrame*>&, nsRect*, AnimatedGeometryRoot**, nsTArray<nsIFrame*>&) src/layout/painting/RetainedDisplayListBuilder.cpp:997:10 #7 RetainedDisplayListBuilder::AttemptPartialUpdate(unsigned int, mozilla::DisplayListChecker*) src/layout/painting/RetainedDisplayListBuilder.cpp:1141:8 #8 nsLayoutUtils::PaintFrame(gfxContext*, nsIFrame*, nsRegion const&, unsigned int, nsDisplayListBuilderMode, nsLayoutUtils::PaintFrameFlags) src/layout/base/nsLayoutUtils.cpp:3695:40 #9 mozilla::PresShell::Paint(nsView*, nsRegion const&, unsigned int) src/layout/base/PresShell.cpp:6314:5 #10 nsViewManager::ProcessPendingUpdatesPaint(nsIWidget*) src/view/nsViewManager.cpp:480:19 #11 nsViewManager::ProcessPendingUpdatesForView(nsView*, bool) src/view/nsViewManager.cpp:412:33 #12 nsViewManager::ProcessPendingUpdates() src/view/nsViewManager.cpp:1102:5 #13 nsRefreshDriver::Tick(long, mozilla::TimeStamp) src/layout/base/nsRefreshDriver.cpp:2039:11 #14 mozilla::RefreshDriverTimer::TickRefreshDrivers(long, mozilla::TimeStamp, nsTArray<RefPtr<nsRefreshDriver> >&) src/layout/base/nsRefreshDriver.cpp:301:7 #15 mozilla::RefreshDriverTimer::Tick(long, mozilla::TimeStamp) src/layout/base/nsRefreshDriver.cpp:320:5 #16 mozilla::VsyncRefreshDriverTimer::RunRefreshDrivers(mozilla::TimeStamp) src/layout/base/nsRefreshDriver.cpp:760:5 #17 mozilla::VsyncRefreshDriverTimer::RefreshDriverVsyncObserver::TickRefreshDriver(mozilla::TimeStamp) src/layout/base/nsRefreshDriver.cpp:673:35 #18 mozilla::VsyncRefreshDriverTimer::RefreshDriverVsyncObserver::NotifyVsync(mozilla::TimeStamp) src/layout/base/nsRefreshDriver.cpp:574:9 #19 mozilla::layout::VsyncChild::RecvNotify(mozilla::TimeStamp const&) src/layout/ipc/VsyncChild.cpp:68:16 #20 mozilla::layout::PVsyncChild::OnMessageReceived(IPC::Message const&) src/obj-firefox/ipc/ipdl/PVsyncChild.cpp:167:20 #21 mozilla::ipc::PBackgroundChild::OnMessageReceived(IPC::Message const&) src/obj-firefox/ipc/ipdl/PBackgroundChild.cpp:1988:28 #22 mozilla::ipc::MessageChannel::DispatchAsyncMessage(IPC::Message const&) src/ipc/glue/MessageChannel.cpp:2134:25 #23 mozilla::ipc::MessageChannel::DispatchMessage(IPC::Message&&) src/ipc/glue/MessageChannel.cpp:2064:17 #24 mozilla::ipc::MessageChannel::RunMessage(mozilla::ipc::MessageChannel::MessageTask&) src/ipc/glue/MessageChannel.cpp:1910:5 #25 mozilla::ipc::MessageChannel::MessageTask::Run() src/ipc/glue/MessageChannel.cpp:1943:15 #26 nsThread::ProcessNextEvent(bool, bool*) src/xpcom/threads/nsThread.cpp:1088:14 #27 NS_ProcessNextEvent(nsIThread*, bool) src/xpcom/threads/nsThreadUtils.cpp:519:10 #28 mozilla::ipc::MessagePump::Run(base::MessagePump::Delegate*) src/ipc/glue/MessagePump.cpp:97:21 #29 MessageLoop::RunInternal() src/ipc/chromium/src/base/message_loop.cc:325:10 #30 MessageLoop::Run() src/ipc/chromium/src/base/message_loop.cc:298:3 #31 nsBaseAppShell::Run() src/widget/nsBaseAppShell.cpp:157:27 #32 XRE_RunAppShell() src/toolkit/xre/nsEmbedFunctions.cpp:896:22 #33 mozilla::ipc::MessagePumpForChildProcess::Run(base::MessagePump::Delegate*) src/ipc/glue/MessagePump.cpp:269:9 #34 MessageLoop::RunInternal() src/ipc/chromium/src/base/message_loop.cc:325:10 #35 MessageLoop::Run() src/ipc/chromium/src/base/message_loop.cc:298:3 #36 XRE_InitChildProcess(int, char**, XREChildData const*) src/toolkit/xre/nsEmbedFunctions.cpp:722:34 #37 content_process_main(mozilla::Bootstrap*, int, char**) src/browser/app/../../ipc/contentproc/plugin-container.cpp:50:30 #38 main src/browser/app/nsBrowserApp.cpp:287:18 #39 __libc_start_main /build/glibc-Cl5G7W/glibc-2.23/csu/../csu/libc-start.c:291 #40 _start (firefox+0x4236e4)

layout/svg belongs to SVG module anyway, so maybe that's a better start point.