Found while fuzzing m-c 20240210-a4ac5f36f609 (--enable-debug --enable-fuzzing)

To reproduce via Grizzly Replay:

$ pip install fuzzfetch grizzly-framework
$ python -m fuzzfetch -d --fuzzing -n firefox
$ python -m grizzly.replay.bugzilla ./firefox/firefox <bugid>

Assertion failure: !reflowStatus.IsInlineBreak() && !pushedFrame (Any line break inside ruby box should has been suppressed), at /builds/worker/checkouts/gecko/layout/generic/nsRubyBaseContainerFrame.cpp:816

#0 0x7fe03b6b6bbe in nsRubyBaseContainerFrame::ReflowSpans(nsRubyBaseContainerFrame::RubyReflowInput const&) /builds/worker/checkouts/gecko/layout/generic/nsRubyBaseContainerFrame.cpp:815:5
#1 0x7fe03b6b5ecd in nsRubyBaseContainerFrame::Reflow(nsPresContext*, mozilla::ReflowOutput&, mozilla::ReflowInput const&, nsReflowStatus&) /builds/worker/checkouts/gecko/layout/generic/nsRubyBaseContainerFrame.cpp:382:25
#2 0x7fe03b699d25 in nsLineLayout::ReflowFrame(nsIFrame*, nsReflowStatus&, mozilla::ReflowOutput*, bool&) /builds/worker/checkouts/gecko/layout/generic/nsLineLayout.cpp:894:13
#3 0x7fe03b6b95bc in nsRubyFrame::ReflowSegment(nsPresContext*, mozilla::ReflowInput const&, int, int, nsRubyBaseContainerFrame*, nsReflowStatus&) /builds/worker/checkouts/gecko/layout/generic/nsRubyFrame.cpp:189:29
#4 0x7fe03b6b8fff in nsRubyFrame::Reflow(nsPresContext*, mozilla::ReflowOutput&, mozilla::ReflowInput const&, nsReflowStatus&) /builds/worker/checkouts/gecko/layout/generic/nsRubyFrame.cpp:133:5
#5 0x7fe03b699d25 in nsLineLayout::ReflowFrame(nsIFrame*, nsReflowStatus&, mozilla::ReflowOutput*, bool&) /builds/worker/checkouts/gecko/layout/generic/nsLineLayout.cpp:894:13
#6 0x7fe03b58153f in nsBlockFrame::ReflowInlineFrame(mozilla::BlockReflowState&, nsLineLayout&, nsLineList_iterator, nsIFrame*, LineReflowStatus*) /builds/worker/checkouts/gecko/layout/generic/nsBlockFrame.cpp:5014:15
#7 0x7fe03b580739 in nsBlockFrame::DoReflowInlineFrames(mozilla::BlockReflowState&, nsLineLayout&, nsLineList_iterator, nsFlowAreaRect&, int&, nsFloatManager::SavedState*, bool*, LineReflowStatus*, bool) /builds/worker/checkouts/gecko/layout/generic/nsBlockFrame.cpp:4816:5
#8 0x7fe03b57c638 in nsBlockFrame::ReflowInlineFrames(mozilla::BlockReflowState&, nsLineList_iterator, bool*) /builds/worker/checkouts/gecko/layout/generic/nsBlockFrame.cpp:4688:9
#9 0x7fe03b578a48 in nsBlockFrame::ReflowLine(mozilla::BlockReflowState&, nsLineList_iterator, bool*) /builds/worker/checkouts/gecko/layout/generic/nsBlockFrame.cpp:3656:24
#10 0x7fe03b573681 in nsBlockFrame::ReflowDirtyLines(mozilla::BlockReflowState&) /builds/worker/checkouts/gecko/layout/generic/nsBlockFrame.cpp:3162:29
#11 0x7fe03b5703cb in nsBlockFrame::TrialReflow(nsPresContext*, mozilla::ReflowOutput&, mozilla::ReflowInput const&, nsBlockFrame::TrialReflowState&) /builds/worker/checkouts/gecko/layout/generic/nsBlockFrame.cpp:1911:35
#12 0x7fe03b56e5cb in nsBlockFrame::Reflow(nsPresContext*, mozilla::ReflowOutput&, mozilla::ReflowInput const&, nsReflowStatus&) /builds/worker/checkouts/gecko/layout/generic/nsBlockFrame.cpp:1556:9
#13 0x7fe03b57f459 in nsBlockReflowContext::ReflowBlock(mozilla::LogicalRect const&, bool, nsCollapsingMargin&, int, nsLineBox*, mozilla::ReflowInput&, nsReflowStatus&, mozilla::BlockReflowState&) /builds/worker/checkouts/gecko/layout/generic/nsBlockReflowContext.cpp:290:11
#14 0x7fe03b57b290 in nsBlockFrame::ReflowBlockFrame(mozilla::BlockReflowState&, nsLineList_iterator, bool*) /builds/worker/checkouts/gecko/layout/generic/nsBlockFrame.cpp:4323:11
#15 0x7fe03b578afd in nsBlockFrame::ReflowLine(mozilla::BlockReflowState&, nsLineList_iterator, bool*) /builds/worker/checkouts/gecko/layout/generic/nsBlockFrame.cpp:3653:5
#16 0x7fe03b573681 in nsBlockFrame::ReflowDirtyLines(mozilla::BlockReflowState&) /builds/worker/checkouts/gecko/layout/generic/nsBlockFrame.cpp:3162:29
#17 0x7fe03b5703cb in nsBlockFrame::TrialReflow(nsPresContext*, mozilla::ReflowOutput&, mozilla::ReflowInput const&, nsBlockFrame::TrialReflowState&) /builds/worker/checkouts/gecko/layout/generic/nsBlockFrame.cpp:1911:35
#18 0x7fe03b56e5cb in nsBlockFrame::Reflow(nsPresContext*, mozilla::ReflowOutput&, mozilla::ReflowInput const&, nsReflowStatus&) /builds/worker/checkouts/gecko/layout/generic/nsBlockFrame.cpp:1556:9
#19 0x7fe03b5a3ac4 in nsContainerFrame::ReflowChild(nsIFrame*, nsPresContext*, mozilla::ReflowOutput&, mozilla::ReflowInput const&, mozilla::WritingMode const&, mozilla::LogicalPoint const&, nsSize const&, nsIFrame::ReflowChildFlags, nsReflowStatus&, nsOverflowContinuationTracker*) /builds/worker/checkouts/gecko/layout/generic/nsContainerFrame.cpp:886:14
#20 0x7fe03b591a36 in nsCanvasFrame::Reflow(nsPresContext*, mozilla::ReflowOutput&, mozilla::ReflowInput const&, nsReflowStatus&) /builds/worker/checkouts/gecko/layout/generic/nsCanvasFrame.cpp:729:7
#21 0x7fe03b5a3ac4 in nsContainerFrame::ReflowChild(nsIFrame*, nsPresContext*, mozilla::ReflowOutput&, mozilla::ReflowInput const&, mozilla::WritingMode const&, mozilla::LogicalPoint const&, nsSize const&, nsIFrame::ReflowChildFlags, nsReflowStatus&, nsOverflowContinuationTracker*) /builds/worker/checkouts/gecko/layout/generic/nsContainerFrame.cpp:886:14
#22 0x7fe03b5e9847 in nsHTMLScrollFrame::ReflowScrolledFrame(mozilla::ScrollReflowInput&, bool, bool, mozilla::ReflowOutput*) /builds/worker/checkouts/gecko/layout/generic/nsGfxScrollFrame.cpp:915:3
#23 0x7fe03b5ea71e in nsHTMLScrollFrame::ReflowContents(mozilla::ScrollReflowInput&, mozilla::ReflowOutput const&) /builds/worker/checkouts/gecko/layout/generic/nsGfxScrollFrame.cpp:1048:3
#24 0x7fe03b5ef35c in nsHTMLScrollFrame::Reflow(nsPresContext*, mozilla::ReflowOutput&, mozilla::ReflowInput const&, nsReflowStatus&) /builds/worker/checkouts/gecko/layout/generic/nsGfxScrollFrame.cpp:1523:3
#25 0x7fe03b5a3fb1 in nsContainerFrame::ReflowChild(nsIFrame*, nsPresContext*, mozilla::ReflowOutput&, mozilla::ReflowInput const&, int, int, nsIFrame::ReflowChildFlags, nsReflowStatus&, nsOverflowContinuationTracker*) /builds/worker/checkouts/gecko/layout/generic/nsContainerFrame.cpp:927:14
#26 0x7fe03b56449e in mozilla::ViewportFrame::Reflow(nsPresContext*, mozilla::ReflowOutput&, mozilla::ReflowInput const&, nsReflowStatus&) /builds/worker/checkouts/gecko/layout/generic/ViewportFrame.cpp:368:7
#27 0x7fe03b44e344 in mozilla::PresShell::DoReflow(nsIFrame*, bool, mozilla::OverflowChangedTracker*) /builds/worker/checkouts/gecko/layout/base/PresShell.cpp:9785:11
#28 0x7fe03b477c3f in mozilla::PresShell::ProcessReflowCommands(bool) /builds/worker/checkouts/gecko/layout/base/PresShell.cpp:9958:22
#29 0x7fe03b458803 in DoFlushLayout /builds/worker/checkouts/gecko/layout/base/PresShell.cpp:10005:10
#30 0x7fe03b458803 in mozilla::PresShell::DoFlushPendingNotifications(mozilla::ChangesToFlush) /builds/worker/checkouts/gecko/layout/base/PresShell.cpp:4361:11
#31 0x7fe03b41cb3e in FlushPendingNotifications /builds/worker/workspace/obj-build/dist/include/mozilla/PresShell.h:1474:5
#32 0x7fe03b41cb3e in nsRefreshDriver::TickObserverArray(unsigned int, mozilla::TimeStamp) /builds/worker/checkouts/gecko/layout/base/nsRefreshDriver.cpp:2531:18
#33 0x7fe03b419444 in nsRefreshDriver::Tick(mozilla::layers::BaseTransactionId<mozilla::VsyncIdType>, mozilla::TimeStamp, nsRefreshDriver::IsExtraTick) /builds/worker/checkouts/gecko/layout/base/nsRefreshDriver.cpp:2735:28
#34 0x7fe03b422f61 in TickDriver /builds/worker/checkouts/gecko/layout/base/nsRefreshDriver.cpp:367:13
#35 0x7fe03b422f61 in mozilla::RefreshDriverTimer::TickRefreshDrivers(mozilla::layers::BaseTransactionId<mozilla::VsyncIdType>, mozilla::TimeStamp, nsTArray<RefPtr<nsRefreshDriver>>&) /builds/worker/checkouts/gecko/layout/base/nsRefreshDriver.cpp:345:7
#36 0x7fe03b422e60 in mozilla::RefreshDriverTimer::Tick(mozilla::layers::BaseTransactionId<mozilla::VsyncIdType>, mozilla::TimeStamp) /builds/worker/checkouts/gecko/layout/base/nsRefreshDriver.cpp:361:5
#37 0x7fe03b422cfd in mozilla::VsyncRefreshDriverTimer::RunRefreshDrivers(mozilla::layers::BaseTransactionId<mozilla::VsyncIdType>, mozilla::TimeStamp) /builds/worker/checkouts/gecko/layout/base/nsRefreshDriver.cpp:951:5
#38 0x7fe03b421f9c in mozilla::VsyncRefreshDriverTimer::TickRefreshDriver(mozilla::layers::BaseTransactionId<mozilla::VsyncIdType>, mozilla::TimeStamp) /builds/worker/checkouts/gecko/layout/base/nsRefreshDriver.cpp:861:5
#39 0x7fe03b421209 in mozilla::VsyncRefreshDriverTimer::RefreshDriverVsyncObserver::NotifyVsyncTimerOnMainThread() /builds/worker/checkouts/gecko/layout/base/nsRefreshDriver.cpp:592:14
#40 0x7fe03a73c93b in mozilla::dom::VsyncMainChild::RecvNotify(mozilla::VsyncEvent const&, float const&) /builds/worker/checkouts/gecko/dom/ipc/VsyncMainChild.cpp:66:15
#41 0x7fe03aa2cb3d in mozilla::dom::PVsyncChild::OnMessageReceived(IPC::Message const&) /builds/worker/workspace/obj-build/ipc/ipdl/PVsyncChild.cpp:237:78
#42 0x7fe03a9147a0 in mozilla::dom::PContentChild::OnMessageReceived(IPC::Message const&) /builds/worker/workspace/obj-build/ipc/ipdl/PContentChild.cpp:8277:32
#43 0x7fe0367e645f in mozilla::ipc::MessageChannel::DispatchAsyncMessage(mozilla::ipc::ActorLifecycleProxy*, IPC::Message const&) /builds/worker/checkouts/gecko/ipc/glue/MessageChannel.cpp:1813:25
#44 0x7fe0367e31b2 in mozilla::ipc::MessageChannel::DispatchMessage(mozilla::ipc::ActorLifecycleProxy*, mozilla::UniquePtr<IPC::Message, mozilla::DefaultDelete<IPC::Message>>) /builds/worker/checkouts/gecko/ipc/glue/MessageChannel.cpp:1732:9
#45 0x7fe0367e3e32 in mozilla::ipc::MessageChannel::RunMessage(mozilla::ipc::ActorLifecycleProxy*, mozilla::ipc::MessageChannel::MessageTask&) /builds/worker/checkouts/gecko/ipc/glue/MessageChannel.cpp:1525:3
#46 0x7fe0367e4f7f in mozilla::ipc::MessageChannel::MessageTask::Run() /builds/worker/checkouts/gecko/ipc/glue/MessageChannel.cpp:1623:14
#47 0x7fe035ae9f27 in mozilla::RunnableTask::Run() /builds/worker/checkouts/gecko/xpcom/threads/TaskController.cpp:578:16
#48 0x7fe035adf696 in mozilla::TaskController::DoExecuteNextTaskOnlyMainThreadInternal(mozilla::detail::BaseAutoLock<mozilla::Mutex&> const&) /builds/worker/checkouts/gecko/xpcom/threads/TaskController.cpp:905:26
#49 0x7fe035adde77 in mozilla::TaskController::ExecuteNextTaskOnlyMainThreadInternal(mozilla::detail::BaseAutoLock<mozilla::Mutex&> const&) /builds/worker/checkouts/gecko/xpcom/threads/TaskController.cpp:728:15
#50 0x7fe035ade2f5 in mozilla::TaskController::ProcessPendingMTTask(bool) /builds/worker/checkouts/gecko/xpcom/threads/TaskController.cpp:514:36
#51 0x7fe035aedf39 in operator() /builds/worker/checkouts/gecko/xpcom/threads/TaskController.cpp:235:37
#52 0x7fe035aedf39 in mozilla::detail::RunnableFunction<mozilla::TaskController::TaskController()::$_1>::Run() /builds/worker/checkouts/gecko/xpcom/threads/nsThreadUtils.h:548:5
#53 0x7fe035b03232 in nsThread::ProcessNextEvent(bool, bool*) /builds/worker/checkouts/gecko/xpcom/threads/nsThread.cpp:1199:16
#54 0x7fe035b0a37d in NS_ProcessNextEvent(nsIThread*, bool) /builds/worker/checkouts/gecko/xpcom/threads/nsThreadUtils.cpp:480:10
#55 0x7fe0367ec373 in mozilla::ipc::MessagePump::Run(base::MessagePump::Delegate*) /builds/worker/checkouts/gecko/ipc/glue/MessagePump.cpp:107:5
#56 0x7fe036702751 in RunHandler /builds/worker/checkouts/gecko/ipc/chromium/src/base/message_loop.cc:363:3
#57 0x7fe036702751 in MessageLoop::Run() /builds/worker/checkouts/gecko/ipc/chromium/src/base/message_loop.cc:345:3
#58 0x7fe03b050128 in nsBaseAppShell::Run() /builds/worker/checkouts/gecko/widget/nsBaseAppShell.cpp:148:27
#59 0x7fe03b10ff18 in nsAppShell::Run() /builds/worker/checkouts/gecko/widget/gtk/nsAppShell.cpp:470:33
#60 0x7fe03cf43dfb in XRE_RunAppShell() /builds/worker/checkouts/gecko/toolkit/xre/nsEmbedFunctions.cpp:721:20
#61 0x7fe0367ed2a6 in mozilla::ipc::MessagePumpForChildProcess::Run(base::MessagePump::Delegate*) /builds/worker/checkouts/gecko/ipc/glue/MessagePump.cpp:235:9
#62 0x7fe036702751 in RunHandler /builds/worker/checkouts/gecko/ipc/chromium/src/base/message_loop.cc:363:3
#63 0x7fe036702751 in MessageLoop::Run() /builds/worker/checkouts/gecko/ipc/chromium/src/base/message_loop.cc:345:3
#64 0x7fe03cf43662 in XRE_InitChildProcess(int, char**, XREChildData const*) /builds/worker/checkouts/gecko/toolkit/xre/nsEmbedFunctions.cpp:656:34
#65 0x559cb7a173b6 in content_process_main /builds/worker/checkouts/gecko/browser/app/../../ipc/contentproc/plugin-container.cpp:57:28
#66 0x559cb7a173b6 in main /builds/worker/checkouts/gecko/browser/app/nsBrowserApp.cpp:375:18
#67 0x7fe04a629d8f in __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58:16
#68 0x7fe04a629e3f in __libc_start_main csu/../csu/libc-start.c:392:3
#69 0x559cb79ed0e8 in _start (/home/user/workspace/browsers/m-c-20240221213323-fuzzing-debug/firefox-bin+0x590e8) (BuildId: c162947dc2f025b1b7870e81310d1341a8a9b38d)

Verified bug as reproducible on mozilla-central 20240222043825-445c60e096fe.
Unable to bisect testcase (Testcase reproduces on start build!):

Start: e4d0dac7f34f555d2085fd2f9fe07dc9318c87a6 (20230223094032)
End: a4ac5f36f609ad4a87fb047393aab7e4445270b4 (20240210094249)
BuildFlags: BuildFlags(asan=False, tsan=False, debug=True, fuzzing=True, coverage=False, valgrind=False, no_opt=False, fuzzilli=False, nyx=False)

It's unfortunate bisect was failed. S3 because it's a debug assertion.