Assertion failure: sideToMeasureFrom == eSideBottom (We already checked that we're dealing with a vertical axis, and we're not using the top side, so that only leaves the bottom...), at src/layout/generic/nsFlexContainerFrame.cpp:1987 #0 nsFlexContainerFrame::FlexItem::GetBaselineOffsetFromOuterCrossEdge(AxisEdgeType, nsFlexContainerFrame::FlexboxAxisTracker const&, bool) const src/layout/generic/nsFlexContainerFrame.cpp:1967:3 #1 nsFlexContainerFrame::FlexLine::ComputeCrossSizeAndBaseline(nsFlexContainerFrame::FlexboxAxisTracker const&) src/layout/generic/nsFlexContainerFrame.cpp:3229:15 #2 nsFlexContainerFrame::DoFlexLayout(nsPresContext*, mozilla::ReflowOutput&, mozilla::ReflowInput const&, nsReflowStatus&, int, int, nsTArray<nsFlexContainerFrame::StrutInfo>&, nsFlexContainerFrame::FlexboxAxisTracker const&) src/layout/generic/nsFlexContainerFrame.cpp:4542:11 #3 nsFlexContainerFrame::Reflow(nsPresContext*, mozilla::ReflowOutput&, mozilla::ReflowInput const&, nsReflowStatus&) src/layout/generic/nsFlexContainerFrame.cpp:4200:3 #4 nsBlockReflowContext::ReflowBlock(mozilla::LogicalRect const&, bool, nsCollapsingMargin&, int, bool, nsLineBox*, mozilla::ReflowInput&, nsReflowStatus&, mozilla::BlockReflowInput&) src/layout/generic/nsBlockReflowContext.cpp:306:11 #5 nsBlockFrame::ReflowBlockFrame(mozilla::BlockReflowInput&, nsLineList_iterator, bool*) src/layout/generic/nsBlockFrame.cpp:3463:11 #6 nsBlockFrame::ReflowLine(mozilla::BlockReflowInput&, nsLineList_iterator, bool*) src/layout/generic/nsBlockFrame.cpp:2813:5 #7 nsBlockFrame::ReflowDirtyLines(mozilla::BlockReflowInput&) src/layout/generic/nsBlockFrame.cpp:2352:7 #8 nsBlockFrame::Reflow(nsPresContext*, mozilla::ReflowOutput&, mozilla::ReflowInput const&, nsReflowStatus&) src/layout/generic/nsBlockFrame.cpp:1225:3 #9 nsBlockReflowContext::ReflowBlock(mozilla::LogicalRect const&, bool, nsCollapsingMargin&, int, bool, nsLineBox*, mozilla::ReflowInput&, nsReflowStatus&, mozilla::BlockReflowInput&) src/layout/generic/nsBlockReflowContext.cpp:306:11 #10 nsBlockFrame::ReflowBlockFrame(mozilla::BlockReflowInput&, nsLineList_iterator, bool*) src/layout/generic/nsBlockFrame.cpp:3463:11 #11 nsBlockFrame::ReflowLine(mozilla::BlockReflowInput&, nsLineList_iterator, bool*) src/layout/generic/nsBlockFrame.cpp:2813:5 #12 nsBlockFrame::ReflowDirtyLines(mozilla::BlockReflowInput&) src/layout/generic/nsBlockFrame.cpp:2352:7 #13 nsBlockFrame::Reflow(nsPresContext*, mozilla::ReflowOutput&, mozilla::ReflowInput const&, nsReflowStatus&) src/layout/generic/nsBlockFrame.cpp:1225:3 #14 nsContainerFrame::ReflowChild(nsIFrame*, nsPresContext*, mozilla::ReflowOutput&, mozilla::ReflowInput const&, mozilla::WritingMode const&, mozilla::LogicalPoint const&, nsSize const&, unsigned int, nsReflowStatus&, nsOverflowContinuationTracker*) src/layout/generic/nsContainerFrame.cpp:941:14 #15 nsCanvasFrame::Reflow(nsPresContext*, mozilla::ReflowOutput&, mozilla::ReflowInput const&, nsReflowStatus&) src/layout/generic/nsCanvasFrame.cpp:720:5 #16 nsContainerFrame::ReflowChild(nsIFrame*, nsPresContext*, mozilla::ReflowOutput&, mozilla::ReflowInput const&, mozilla::WritingMode const&, mozilla::LogicalPoint const&, nsSize const&, unsigned int, nsReflowStatus&, nsOverflowContinuationTracker*) src/layout/generic/nsContainerFrame.cpp:941:14 #17 nsHTMLScrollFrame::ReflowScrolledFrame(mozilla::ScrollReflowInput*, bool, bool, mozilla::ReflowOutput*, bool) src/layout/generic/nsGfxScrollFrame.cpp:554:3 #18 nsHTMLScrollFrame::ReflowContents(mozilla::ScrollReflowInput*, mozilla::ReflowOutput const&) src/layout/generic/nsGfxScrollFrame.cpp:677:3 #19 nsHTMLScrollFrame::Reflow(nsPresContext*, mozilla::ReflowOutput&, mozilla::ReflowInput const&, nsReflowStatus&) src/layout/generic/nsGfxScrollFrame.cpp:1054:3 #20 nsContainerFrame::ReflowChild(nsIFrame*, nsPresContext*, mozilla::ReflowOutput&, mozilla::ReflowInput const&, int, int, unsigned int, nsReflowStatus&, nsOverflowContinuationTracker*) src/layout/generic/nsContainerFrame.cpp:985:14 #21 mozilla::ViewportFrame::Reflow(nsPresContext*, mozilla::ReflowOutput&, mozilla::ReflowInput const&, nsReflowStatus&) src/layout/generic/ViewportFrame.cpp:335:7 #22 mozilla::PresShell::DoReflow(nsIFrame*, bool) src/layout/base/PresShell.cpp:8967:11 #23 mozilla::PresShell::ProcessReflowCommands(bool) src/layout/base/PresShell.cpp:9140:24 #24 mozilla::PresShell::DoFlushPendingNotifications(mozilla::ChangesToFlush) src/layout/base/PresShell.cpp:4257:11 #25 nsRefreshDriver::Tick(long, mozilla::TimeStamp) src/layout/base/nsRefreshDriver.cpp:1944:16 #26 mozilla::RefreshDriverTimer::TickRefreshDrivers(long, mozilla::TimeStamp, nsTArray<RefPtr<nsRefreshDriver> >&) src/layout/base/nsRefreshDriver.cpp:310:7 #27 mozilla::RefreshDriverTimer::Tick(long, mozilla::TimeStamp) src/layout/base/nsRefreshDriver.cpp:331:5 #28 mozilla::VsyncRefreshDriverTimer::RunRefreshDrivers(mozilla::TimeStamp) src/layout/base/nsRefreshDriver.cpp:773:5 #29 mozilla::VsyncRefreshDriverTimer::RefreshDriverVsyncObserver::TickRefreshDriver(mozilla::TimeStamp) src/layout/base/nsRefreshDriver.cpp:686:35 #30 mozilla::VsyncRefreshDriverTimer::RefreshDriverVsyncObserver::ParentProcessVsyncNotifier::Run() src/layout/base/nsRefreshDriver.cpp:532:20 #31 nsThread::ProcessNextEvent(bool, bool*) src/xpcom/threads/nsThread.cpp:1040:14 #32 NS_ProcessNextEvent(nsIThread*, bool) src/xpcom/threads/nsThreadUtils.cpp:517:10 #33 mozilla::ipc::MessagePump::Run(base::MessagePump::Delegate*) src/ipc/glue/MessagePump.cpp:97:21 #34 MessageLoop::RunInternal() src/ipc/chromium/src/base/message_loop.cc:326:10 #35 MessageLoop::Run() src/ipc/chromium/src/base/message_loop.cc:299:3 #36 nsBaseAppShell::Run() src/widget/nsBaseAppShell.cpp:157:27 #37 nsAppStartup::Run() src/toolkit/components/startup/nsAppStartup.cpp:288:30 #38 XREMain::XRE_mainRun() src/toolkit/xre/nsAppRunner.cpp:4679:22 #39 XREMain::XRE_main(int, char**, mozilla::BootstrapConfig const&) src/toolkit/xre/nsAppRunner.cpp:4814:8 #40 XRE_main(int, char**, mozilla::BootstrapConfig const&) src/toolkit/xre/nsAppRunner.cpp:4906:21 #41 do_main(int, char**, char**) src/browser/app/nsBrowserApp.cpp:231:22 #42 main src/browser/app/nsBrowserApp.cpp:304:16 #43 __libc_start_main /build/glibc-Cl5G7W/glibc-2.23/csu/../csu/libc-start.c:291 #44 _start (firefox+0x423444)

This is basically the same as bug 1384266, but I've just recently landed a refactoring patch-series (bug 1174003) that makes us get past that bug's original assertion and to this next one.