Reduced with m-c:
BuildID=20190705161030
SourceStamp=c7e91f614eb78c4447a623f1c88a66421113ab07

Assertion failure: !HasAnyStateBits(NS_FRAME_IS_DIRTY | NS_FRAME_FIRST_REFLOW) (frame should have been reflowed), at src/layout/generic/nsTextFrame.cpp:9437

#0 nsTextFrame::TrimTrailingWhiteSpace(mozilla::gfx::DrawTarget*) src/layout/generic/nsTextFrame.cpp:9436:3
#1 nsLineLayout::TrimTrailingWhiteSpaceIn(nsLineLayout::PerSpanData*, int*) src/layout/generic/nsLineLayout.cpp:2551:17
#2 nsLineLayout::TrimTrailingWhiteSpaceIn(nsLineLayout::PerSpanData*, int*) src/layout/generic/nsLineLayout.cpp:2498:11
#3 nsLineLayout::TrimTrailingWhiteSpace() src/layout/generic/nsLineLayout.cpp:2618:3
#4 nsBlockFrame::PlaceLine(mozilla::BlockReflowInput&, nsLineLayout&, nsLineList_iterator, nsFloatManager::SavedState*, nsFlowAreaRect&, int&, bool*) src/layout/generic/nsBlockFrame.cpp:4609:15
#5 nsBlockFrame::DoReflowInlineFrames(mozilla::BlockReflowInput&, nsLineLayout&, nsLineList_iterator, nsFlowAreaRect&, int&, nsFloatManager::SavedState*, bool*, LineReflowStatus*, bool) src/layout/generic/nsBlockFrame.cpp:4231:12
#6 nsBlockFrame::ReflowInlineFrames(mozilla::BlockReflowInput&, nsLineList_iterator, bool*) src/layout/generic/nsBlockFrame.cpp:3989:9
#7 nsBlockFrame::ReflowLine(mozilla::BlockReflowInput&, nsLineList_iterator, bool*) src/layout/generic/nsBlockFrame.cpp:2994:5
#8 nsBlockFrame::ReflowDirtyLines(mozilla::BlockReflowInput&) src/layout/generic/nsBlockFrame.cpp:2535:7
#9 nsBlockFrame::Reflow(nsPresContext*, mozilla::ReflowOutput&, mozilla::ReflowInput const&, nsReflowStatus&) src/layout/generic/nsBlockFrame.cpp:1285:3
#10 nsBlockReflowContext::ReflowBlock(mozilla::LogicalRect const&, bool, nsCollapsingMargin&, int, bool, nsLineBox*, mozilla::ReflowInput&, nsReflowStatus&, mozilla::BlockReflowInput&) src/layout/generic/nsBlockReflowContext.cpp:297:11
#11 nsBlockFrame::ReflowBlockFrame(mozilla::BlockReflowInput&, nsLineList_iterator, bool*) src/layout/generic/nsBlockFrame.cpp:3627:11
#12 nsBlockFrame::ReflowLine(mozilla::BlockReflowInput&, nsLineList_iterator, bool*) src/layout/generic/nsBlockFrame.cpp:2991:5
#13 nsBlockFrame::ReflowDirtyLines(mozilla::BlockReflowInput&) src/layout/generic/nsBlockFrame.cpp:2535:7
#14 nsBlockFrame::Reflow(nsPresContext*, mozilla::ReflowOutput&, mozilla::ReflowInput const&, nsReflowStatus&) src/layout/generic/nsBlockFrame.cpp:1285:3
#15 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:894:14
#16 nsCanvasFrame::Reflow(nsPresContext*, mozilla::ReflowOutput&, mozilla::ReflowInput const&, nsReflowStatus&) src/layout/generic/nsCanvasFrame.cpp:730:5
#17 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:894:14
#18 nsHTMLScrollFrame::ReflowScrolledFrame(mozilla::ScrollReflowInput*, bool, bool, mozilla::ReflowOutput*) src/layout/generic/nsGfxScrollFrame.cpp:625:3
#19 nsHTMLScrollFrame::ReflowContents(mozilla::ScrollReflowInput*, mozilla::ReflowOutput const&) src/layout/generic/nsGfxScrollFrame.cpp:738:3
#20 nsHTMLScrollFrame::Reflow(nsPresContext*, mozilla::ReflowOutput&, mozilla::ReflowInput const&, nsReflowStatus&) src/layout/generic/nsGfxScrollFrame.cpp:1140:3
#21 nsContainerFrame::ReflowChild(nsIFrame*, nsPresContext*, mozilla::ReflowOutput&, mozilla::ReflowInput const&, int, int, unsigned int, nsReflowStatus&, nsOverflowContinuationTracker*) src/layout/generic/nsContainerFrame.cpp:933:14
#22 mozilla::ViewportFrame::Reflow(nsPresContext*, mozilla::ReflowOutput&, mozilla::ReflowInput const&, nsReflowStatus&) src/layout/generic/ViewportFrame.cpp:307:7
#23 mozilla::PresShell::DoReflow(nsIFrame*, bool, mozilla::OverflowChangedTracker*) src/layout/base/PresShell.cpp:9298:11
#24 mozilla::PresShell::ProcessReflowCommands(bool) src/layout/base/PresShell.cpp:9468:24
#25 mozilla::PresShell::DoFlushPendingNotifications(mozilla::ChangesToFlush) src/layout/base/PresShell.cpp:4234:11
#26 nsRefreshDriver::Tick(mozilla::layers::BaseTransactionId<mozilla::VsyncIdType>, mozilla::TimeStamp) src/layout/base/nsRefreshDriver.cpp:1986:20
#27 mozilla::RefreshDriverTimer::TickRefreshDrivers(mozilla::layers::BaseTransactionId<mozilla::VsyncIdType>, mozilla::TimeStamp, nsTArray<RefPtr<nsRefreshDriver> >&) src/layout/base/nsRefreshDriver.cpp:327:7
#28 mozilla::RefreshDriverTimer::Tick(mozilla::layers::BaseTransactionId<mozilla::VsyncIdType>, mozilla::TimeStamp) src/layout/base/nsRefreshDriver.cpp:344:5
#29 mozilla::VsyncRefreshDriverTimer::RefreshDriverVsyncObserver::TickRefreshDriver(mozilla::layers::BaseTransactionId<mozilla::VsyncIdType>, mozilla::TimeStamp) src/layout/base/nsRefreshDriver.cpp:710:16
#30 mozilla::VsyncRefreshDriverTimer::RefreshDriverVsyncObserver::NotifyVsync(mozilla::VsyncEvent const&) src/layout/base/nsRefreshDriver.cpp:605:9
#31 mozilla::layout::VsyncChild::RecvNotify(mozilla::VsyncEvent const&) src/layout/ipc/VsyncChild.cpp:65:16
#32 mozilla::layout::PVsyncChild::OnMessageReceived(IPC::Message const&) src/obj-firefox/ipc/ipdl/PVsyncChild.cpp:187:54
#33 mozilla::ipc::PBackgroundChild::OnMessageReceived(IPC::Message const&) src/obj-firefox/ipc/ipdl/PBackgroundChild.cpp:4717:32
#34 mozilla::ipc::MessageChannel::DispatchAsyncMessage(mozilla::ipc::ActorLifecycleProxy*, IPC::Message const&) src/ipc/glue/MessageChannel.cpp:2158:25
#35 mozilla::ipc::MessageChannel::DispatchMessage(IPC::Message&&) src/ipc/glue/MessageChannel.cpp:2082:9
#36 mozilla::ipc::MessageChannel::RunMessage(mozilla::ipc::MessageChannel::MessageTask&) src/ipc/glue/MessageChannel.cpp:1939:3
#37 mozilla::ipc::MessageChannel::MessageTask::Run() src/ipc/glue/MessageChannel.cpp:1970:13
#38 nsThread::ProcessNextEvent(bool, bool*) src/xpcom/threads/nsThread.cpp:1225:14
#39 NS_ProcessNextEvent(nsIThread*, bool) src/xpcom/threads/nsThreadUtils.cpp:486:10
#40 mozilla::ipc::MessagePump::Run(base::MessagePump::Delegate*) src/ipc/glue/MessagePump.cpp:110:5
#41 MessageLoop::RunInternal() src/ipc/chromium/src/base/message_loop.cc:315:10
#42 MessageLoop::Run() src/ipc/chromium/src/base/message_loop.cc:290:3
#43 nsBaseAppShell::Run() src/widget/nsBaseAppShell.cpp:137:27
#44 XRE_RunAppShell() src/toolkit/xre/nsEmbedFunctions.cpp:919:20
#45 mozilla::ipc::MessagePumpForChildProcess::Run(base::MessagePump::Delegate*) src/ipc/glue/MessagePump.cpp:238:9
#46 MessageLoop::RunInternal() src/ipc/chromium/src/base/message_loop.cc:315:10
#47 MessageLoop::Run() src/ipc/chromium/src/base/message_loop.cc:290:3
#48 XRE_InitChildProcess(int, char**, XREChildData const*) src/toolkit/xre/nsEmbedFunctions.cpp:754:34
#49 content_process_main(mozilla::Bootstrap*, int, char**) src/browser/app/../../ipc/contentproc/plugin-container.cpp:56:28
#50 main src/browser/app/nsBrowserApp.cpp:267:18

This isn't a particularly concerning regression because what really happened, given what regressed things, is that the patch made the assertion more accurate by causing NS_FRAME_IS_DIRTY to be set for a larger percentage of the cases when the frame is, in fact, dirty. That said, it might be being set in cases that are less relevant to what was being asserted, if the assertion was particularly about some of the data in text frames being dirty rather than general layout dirtiness. However, it's likely still pointing out a case where we're doing wasted work.

The priority flag is not set for this bug.
:emilio, could you have a look please?

For more information, please visit auto_nag documentation.

Per comment 1 this looks like a P3.

There is a spike in reports from fuzzers starting with m-c 20221220-dd4482632694.

Oops attached over reduced version, fixed.

A Pernosco session is available here: https://pernos.co/debug/7zeUs9-ZyZcgl4hasZdPnA/index.html

This issue is frequently reported by fuzzers.

jfkthame: is there anyone available to have a look at this?