Found while fuzzing m-c 20220930-2d182255c548 (--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 ./firefox/firefox testcase.html

Assertion failure: aPointToInsert.IsSetAndValid(), at /builds/worker/checkouts/gecko/editor/libeditor/HTMLEditSubActionHandler.cpp:6363

#0 0x7f9900e5ee3b in mozilla::HTMLEditor::InsertDivElementToAlignContents(mozilla::EditorDOMPointBase<nsCOMPtr<nsINode>, nsCOMPtr<nsIContent> > const&, nsTSubstring<char16_t> const&, mozilla::dom::Element const&) /builds/worker/checkouts/gecko/editor/libeditor/HTMLEditSubActionHandler.cpp:6363:3
#1 0x7f9900e5d6cf in mozilla::HTMLEditor::AlignContentsAtRanges(mozilla::AutoRangeArray&, nsTSubstring<char16_t> const&, mozilla::dom::Element const&) /builds/worker/checkouts/gecko/editor/libeditor/HTMLEditSubActionHandler.cpp:6303:9
#2 0x7f9900e5c834 in mozilla::HTMLEditor::AlignAsSubAction(nsTSubstring<char16_t> const&, mozilla::dom::Element const&) /builds/worker/checkouts/gecko/editor/libeditor/HTMLEditSubActionHandler.cpp:6156:8
#3 0x7f9900e856f0 in mozilla::HTMLEditor::AlignAsAction(nsTSubstring<char16_t> const&, nsIPrincipal*) /builds/worker/checkouts/gecko/editor/libeditor/HTMLEditor.cpp:2886:7
#4 0x7f9900e9910b in mozilla::AlignCommand::SetState(mozilla::HTMLEditor*, nsTSubstring<char16_t> const&, nsIPrincipal*) const /builds/worker/checkouts/gecko/editor/libeditor/HTMLEditorCommands.cpp:868:30
#5 0x7f9900e973fe in mozilla::MultiStateCommandBase::DoCommandParam(mozilla::Command, nsTSubstring<char16_t> const&, mozilla::EditorBase&, nsIPrincipal*) const /builds/worker/checkouts/gecko/editor/libeditor/HTMLEditorCommands.cpp:490:17
#6 0x7f98fd714c07 in mozilla::dom::Document::ExecCommand(nsTSubstring<char16_t> const&, bool, nsTSubstring<char16_t> const&, nsIPrincipal&, mozilla::ErrorResult&) /builds/worker/checkouts/gecko/dom/base/Document.cpp:5452:27
#7 0x7f98fead8753 in mozilla::dom::Document_Binding::execCommand(JSContext*, JS::Handle<JSObject*>, void*, JSJitMethodCallArgs const&) /builds/worker/workspace/obj-build/dom/bindings/DocumentBinding.cpp:4149:36
#8 0x7f98fee7e5dc in bool mozilla::dom::binding_detail::GenericMethod<mozilla::dom::binding_detail::NormalThisPolicy, mozilla::dom::binding_detail::ThrowExceptions>(JSContext*, unsigned int, JS::Value*) /builds/worker/checkouts/gecko/dom/bindings/BindingUtils.cpp:3287:13
#9 0x7f9904559dbc in CallJSNative(JSContext*, bool (*)(JSContext*, unsigned int, JS::Value*), js::CallReason, JS::CallArgs const&) /builds/worker/checkouts/gecko/js/src/vm/Interpreter.cpp:459:13
#10 0x7f99045596e1 in js::InternalCallOrConstruct(JSContext*, JS::CallArgs const&, js::MaybeConstruct, js::CallReason) /builds/worker/checkouts/gecko/js/src/vm/Interpreter.cpp:547:12
#11 0x7f9904550948 in CallFromStack /builds/worker/checkouts/gecko/js/src/vm/Interpreter.cpp:619:10
#12 0x7f9904550948 in Interpret(JSContext*, js::RunState&) /builds/worker/checkouts/gecko/js/src/vm/Interpreter.cpp:3375:16
#13 0x7f99045479ed in js::RunScript(JSContext*, js::RunState&) /builds/worker/checkouts/gecko/js/src/vm/Interpreter.cpp:431:13
#14 0x7f99045595dd in js::InternalCallOrConstruct(JSContext*, JS::CallArgs const&, js::MaybeConstruct, js::CallReason) /builds/worker/checkouts/gecko/js/src/vm/Interpreter.cpp:579:13
#15 0x7f990455ab1c in js::Call(JSContext*, JS::Handle<JS::Value>, JS::Handle<JS::Value>, js::AnyInvokeArgs const&, JS::MutableHandle<JS::Value>, js::CallReason) /builds/worker/checkouts/gecko/js/src/vm/Interpreter.cpp:646:8
#16 0x7f99031b5d9c in JS::Call(JSContext*, JS::Handle<JS::Value>, JS::Handle<JS::Value>, JS::HandleValueArray const&, JS::MutableHandle<JS::Value>) /builds/worker/checkouts/gecko/js/src/vm/CallAndConstruct.cpp:117:10
#17 0x7f98feb7fda9 in mozilla::dom::EventListener::HandleEvent(mozilla::dom::BindingCallContext&, JS::Handle<JS::Value>, mozilla::dom::Event&, mozilla::ErrorResult&) /builds/worker/workspace/obj-build/dom/bindings/EventListenerBinding.cpp:62:8
#18 0x7f98ff437846 in void mozilla::dom::EventListener::HandleEvent<mozilla::dom::EventTarget*>(mozilla::dom::EventTarget* const&, mozilla::dom::Event&, mozilla::ErrorResult&, char const*, mozilla::dom::CallbackObject::ExceptionHandling, JS::Realm*) /builds/worker/workspace/obj-build/dist/include/mozilla/dom/EventListenerBinding.h:65:12
#19 0x7f98ff43756d in mozilla::EventListenerManager::HandleEventSubType(mozilla::EventListenerManager::Listener*, mozilla::dom::Event*, mozilla::dom::EventTarget*) /builds/worker/checkouts/gecko/dom/events/EventListenerManager.cpp:1310:43
#20 0x7f98ff438217 in mozilla::EventListenerManager::HandleEventInternal(nsPresContext*, mozilla::WidgetEvent*, mozilla::dom::Event**, mozilla::dom::EventTarget*, nsEventStatus*, bool) /builds/worker/checkouts/gecko/dom/events/EventListenerManager.cpp:1506:17
#21 0x7f98ff42d154 in HandleEvent /builds/worker/checkouts/gecko/dom/events/EventListenerManager.h:395:5
#22 0x7f98ff42d154 in mozilla::EventTargetChainItem::HandleEvent(mozilla::EventChainPostVisitor&, mozilla::ELMCreationDetector&) /builds/worker/checkouts/gecko/dom/events/EventDispatcher.cpp:348:17
#23 0x7f98ff42c6a2 in mozilla::EventTargetChainItem::HandleEventTargetChain(nsTArray<mozilla::EventTargetChainItem>&, mozilla::EventChainPostVisitor&, mozilla::EventDispatchingCallback*, mozilla::ELMCreationDetector&) /builds/worker/checkouts/gecko/dom/events/EventDispatcher.cpp:550:16
#24 0x7f98ff42ef41 in mozilla::EventDispatcher::Dispatch(nsISupports*, nsPresContext*, mozilla::WidgetEvent*, mozilla::dom::Event*, nsEventStatus*, mozilla::EventDispatchingCallback*, nsTArray<mozilla::dom::EventTarget*>*) /builds/worker/checkouts/gecko/dom/events/EventDispatcher.cpp:1119:11
#25 0x7f98fd4ea943 in nsContentUtils::MaybeFireNodeRemoved(nsINode*, nsINode*) /builds/worker/checkouts/gecko/dom/base/nsContentUtils.cpp:4945:5
#26 0x7f98fd9ba2a0 in nsINode::ReplaceOrInsertBefore(bool, nsINode*, nsINode*, mozilla::ErrorResult&) /builds/worker/checkouts/gecko/dom/base/nsINode.cpp:2499:7
#27 0x7f98fdf32da9 in InsertBefore /builds/worker/checkouts/gecko/dom/base/nsINode.h:2059:12
#28 0x7f98fdf32da9 in AppendChild /builds/worker/checkouts/gecko/dom/base/nsINode.h:2066:12
#29 0x7f98fdf32da9 in mozilla::dom::Node_Binding::appendChild(JSContext*, JS::Handle<JSObject*>, void*, JSJitMethodCallArgs const&) /builds/worker/workspace/obj-build/dom/bindings/NodeBinding.cpp:997:60
#30 0x7f98fee7e5dc in bool mozilla::dom::binding_detail::GenericMethod<mozilla::dom::binding_detail::NormalThisPolicy, mozilla::dom::binding_detail::ThrowExceptions>(JSContext*, unsigned int, JS::Value*) /builds/worker/checkouts/gecko/dom/bindings/BindingUtils.cpp:3287:13
#31 0x7f9904559dbc in CallJSNative(JSContext*, bool (*)(JSContext*, unsigned int, JS::Value*), js::CallReason, JS::CallArgs const&) /builds/worker/checkouts/gecko/js/src/vm/Interpreter.cpp:459:13
#32 0x7f99045596e1 in js::InternalCallOrConstruct(JSContext*, JS::CallArgs const&, js::MaybeConstruct, js::CallReason) /builds/worker/checkouts/gecko/js/src/vm/Interpreter.cpp:547:12
#33 0x7f9904550948 in CallFromStack /builds/worker/checkouts/gecko/js/src/vm/Interpreter.cpp:619:10
#34 0x7f9904550948 in Interpret(JSContext*, js::RunState&) /builds/worker/checkouts/gecko/js/src/vm/Interpreter.cpp:3375:16
#35 0x7f99045479ed in js::RunScript(JSContext*, js::RunState&) /builds/worker/checkouts/gecko/js/src/vm/Interpreter.cpp:431:13
#36 0x7f99045595dd in js::InternalCallOrConstruct(JSContext*, JS::CallArgs const&, js::MaybeConstruct, js::CallReason) /builds/worker/checkouts/gecko/js/src/vm/Interpreter.cpp:579:13
#37 0x7f990455ab1c in js::Call(JSContext*, JS::Handle<JS::Value>, JS::Handle<JS::Value>, js::AnyInvokeArgs const&, JS::MutableHandle<JS::Value>, js::CallReason) /builds/worker/checkouts/gecko/js/src/vm/Interpreter.cpp:646:8
#38 0x7f99031b5d9c in JS::Call(JSContext*, JS::Handle<JS::Value>, JS::Handle<JS::Value>, JS::HandleValueArray const&, JS::MutableHandle<JS::Value>) /builds/worker/checkouts/gecko/js/src/vm/CallAndConstruct.cpp:117:10
#39 0x7f98feb7d233 in mozilla::dom::EventHandlerNonNull::Call(mozilla::dom::BindingCallContext&, JS::Handle<JS::Value>, mozilla::dom::Event&, JS::MutableHandle<JS::Value>, mozilla::ErrorResult&) /builds/worker/workspace/obj-build/dom/bindings/EventHandlerBinding.cpp:65:37
#40 0x7f98ff4574f9 in void mozilla::dom::EventHandlerNonNull::Call<nsCOMPtr<mozilla::dom::EventTarget> >(nsCOMPtr<mozilla::dom::EventTarget> const&, mozilla::dom::Event&, JS::MutableHandle<JS::Value>, mozilla::ErrorResult&, char const*, mozilla::dom::CallbackObject::ExceptionHandling, JS::Realm*) /builds/worker/workspace/obj-build/dist/include/mozilla/dom/EventHandlerBinding.h:82:12
#41 0x7f98ff4566d3 in mozilla::JSEventHandler::HandleEvent(mozilla::dom::Event*) /builds/worker/checkouts/gecko/dom/events/JSEventHandler.cpp:201:12
#42 0x7f98ff4375ae in mozilla::EventListenerManager::HandleEventSubType(mozilla::EventListenerManager::Listener*, mozilla::dom::Event*, mozilla::dom::EventTarget*) /builds/worker/checkouts/gecko/dom/events/EventListenerManager.cpp:1316:22
#43 0x7f98ff438217 in mozilla::EventListenerManager::HandleEventInternal(nsPresContext*, mozilla::WidgetEvent*, mozilla::dom::Event**, mozilla::dom::EventTarget*, nsEventStatus*, bool) /builds/worker/checkouts/gecko/dom/events/EventListenerManager.cpp:1506:17
#44 0x7f98ff42d154 in HandleEvent /builds/worker/checkouts/gecko/dom/events/EventListenerManager.h:395:5
#45 0x7f98ff42d154 in mozilla::EventTargetChainItem::HandleEvent(mozilla::EventChainPostVisitor&, mozilla::ELMCreationDetector&) /builds/worker/checkouts/gecko/dom/events/EventDispatcher.cpp:348:17
#46 0x7f98ff42c6a2 in mozilla::EventTargetChainItem::HandleEventTargetChain(nsTArray<mozilla::EventTargetChainItem>&, mozilla::EventChainPostVisitor&, mozilla::EventDispatchingCallback*, mozilla::ELMCreationDetector&) /builds/worker/checkouts/gecko/dom/events/EventDispatcher.cpp:550:16
#47 0x7f98ff42ef41 in mozilla::EventDispatcher::Dispatch(nsISupports*, nsPresContext*, mozilla::WidgetEvent*, mozilla::dom::Event*, nsEventStatus*, mozilla::EventDispatchingCallback*, nsTArray<mozilla::dom::EventTarget*>*) /builds/worker/checkouts/gecko/dom/events/EventDispatcher.cpp:1119:11
#48 0x7f99010df653 in nsDocumentViewer::LoadComplete(nsresult) /builds/worker/checkouts/gecko/layout/base/nsDocumentViewer.cpp:1079:7
#49 0x7f9902742fed in nsDocShell::EndPageLoad(nsIWebProgress*, nsIChannel*, nsresult) /builds/worker/checkouts/gecko/docshell/base/nsDocShell.cpp:6436:20
#50 0x7f9902742554 in nsDocShell::OnStateChange(nsIWebProgress*, nsIRequest*, unsigned int, nsresult) /builds/worker/checkouts/gecko/docshell/base/nsDocShell.cpp:5829:7
#51 0x7f9902743f27 in non-virtual thunk to nsDocShell::OnStateChange(nsIWebProgress*, nsIRequest*, unsigned int, nsresult) /builds/worker/checkouts/gecko/docshell/base/nsDocShell.cpp
#52 0x7f98fcbcb8ec in nsDocLoader::DoFireOnStateChange(nsIWebProgress*, nsIRequest*, int&, nsresult) /builds/worker/checkouts/gecko/uriloader/base/nsDocLoader.cpp:1380:3
#53 0x7f98fcbcae2a in nsDocLoader::doStopDocumentLoad(nsIRequest*, nsresult) /builds/worker/checkouts/gecko/uriloader/base/nsDocLoader.cpp:978:14
#54 0x7f98fcbc90e1 in nsDocLoader::DocLoaderIsEmpty(bool, mozilla::Maybe<nsresult> const&) /builds/worker/checkouts/gecko/uriloader/base/nsDocLoader.cpp:797:9
#55 0x7f98fcbca2c8 in nsDocLoader::OnStopRequest(nsIRequest*, nsresult) /builds/worker/checkouts/gecko/uriloader/base/nsDocLoader.cpp:680:5
#56 0x7f9902776f41 in nsDocShell::OnStopRequest(nsIRequest*, nsresult) /builds/worker/checkouts/gecko/docshell/base/nsDocShell.cpp:13841:23
#57 0x7f98fbecc700 in mozilla::net::nsLoadGroup::NotifyRemovalObservers(nsIRequest*, nsresult) /builds/worker/checkouts/gecko/netwerk/base/nsLoadGroup.cpp:628:22
#58 0x7f98fbecdc33 in mozilla::net::nsLoadGroup::RemoveRequest(nsIRequest*, nsISupports*, nsresult) /builds/worker/checkouts/gecko/netwerk/base/nsLoadGroup.cpp:532:10
#59 0x7f98fd741a9d in mozilla::dom::Document::DoUnblockOnload() /builds/worker/checkouts/gecko/dom/base/Document.cpp:11475:18
#60 0x7f98fd70cdaf in mozilla::dom::Document::UnblockOnload(bool) /builds/worker/checkouts/gecko/dom/base/Document.cpp:11413:9
#61 0x7f98fd728204 in mozilla::dom::Document::DispatchContentLoadedEvents() /builds/worker/checkouts/gecko/dom/base/Document.cpp:7949:3
#62 0x7f98fd7dd4bb in applyImpl<mozilla::dom::Document, void (mozilla::dom::Document::*)()> /builds/worker/workspace/obj-build/dist/include/nsThreadUtils.h:1147:12
#63 0x7f98fd7dd4bb in apply<mozilla::dom::Document, void (mozilla::dom::Document::*)()> /builds/worker/workspace/obj-build/dist/include/nsThreadUtils.h:1153:12
#64 0x7f98fd7dd4bb in mozilla::detail::RunnableMethodImpl<mozilla::dom::Document*, void (mozilla::dom::Document::*)(), true, (mozilla::RunnableKind)0>::Run() /builds/worker/workspace/obj-build/dist/include/nsThreadUtils.h:1200:13
#65 0x7f98fbcbd2a2 in mozilla::SchedulerGroup::Runnable::Run() /builds/worker/checkouts/gecko/xpcom/threads/SchedulerGroup.cpp:140:20
#66 0x7f98fbcef1be in mozilla::RunnableTask::Run() /builds/worker/checkouts/gecko/xpcom/threads/TaskController.cpp:538:16
#67 0x7f98fbcc76d9 in mozilla::TaskController::DoExecuteNextTaskOnlyMainThreadInternal(mozilla::detail::BaseAutoLock<mozilla::Mutex&> const&) /builds/worker/checkouts/gecko/xpcom/threads/TaskController.cpp:851:26
#68 0x7f98fbcc6263 in mozilla::TaskController::ExecuteNextTaskOnlyMainThreadInternal(mozilla::detail::BaseAutoLock<mozilla::Mutex&> const&) /builds/worker/checkouts/gecko/xpcom/threads/TaskController.cpp:683:15
#69 0x7f98fbcc64d3 in mozilla::TaskController::ProcessPendingMTTask(bool) /builds/worker/checkouts/gecko/xpcom/threads/TaskController.cpp:461:36
#70 0x7f98fbcf2a66 in operator() /builds/worker/checkouts/gecko/xpcom/threads/TaskController.cpp:187:37
#71 0x7f98fbcf2a66 in mozilla::detail::RunnableFunction<mozilla::TaskController::InitializeInternal()::$_0>::Run() /builds/worker/workspace/obj-build/dist/include/nsThreadUtils.h:531:5
#72 0x7f98fbcdc32f in nsThread::ProcessNextEvent(bool, bool*) /builds/worker/checkouts/gecko/xpcom/threads/nsThread.cpp:1205:16
#73 0x7f98fbce293d in NS_ProcessNextEvent(nsIThread*, bool) /builds/worker/checkouts/gecko/xpcom/threads/nsThreadUtils.cpp:465:10
#74 0x7f98fc8c7d66 in mozilla::ipc::MessagePump::Run(base::MessagePump::Delegate*) /builds/worker/checkouts/gecko/ipc/glue/MessagePump.cpp:85:21
#75 0x7f98fc7ee4c7 in MessageLoop::RunInternal() /builds/worker/checkouts/gecko/ipc/chromium/src/base/message_loop.cc:381:10
#76 0x7f98fc7ee3d2 in RunHandler /builds/worker/checkouts/gecko/ipc/chromium/src/base/message_loop.cc:374:3
#77 0x7f98fc7ee3d2 in MessageLoop::Run() /builds/worker/checkouts/gecko/ipc/chromium/src/base/message_loop.cc:356:3
#78 0x7f9900ceae38 in nsBaseAppShell::Run() /builds/worker/checkouts/gecko/widget/nsBaseAppShell.cpp:150:27
#79 0x7f9902ef0dbb in XRE_RunAppShell() /builds/worker/checkouts/gecko/toolkit/xre/nsEmbedFunctions.cpp:880:20
#80 0x7f98fc8c8c5a in mozilla::ipc::MessagePumpForChildProcess::Run(base::MessagePump::Delegate*) /builds/worker/checkouts/gecko/ipc/glue/MessagePump.cpp:235:9
#81 0x7f98fc7ee4c7 in MessageLoop::RunInternal() /builds/worker/checkouts/gecko/ipc/chromium/src/base/message_loop.cc:381:10
#82 0x7f98fc7ee3d2 in RunHandler /builds/worker/checkouts/gecko/ipc/chromium/src/base/message_loop.cc:374:3
#83 0x7f98fc7ee3d2 in MessageLoop::Run() /builds/worker/checkouts/gecko/ipc/chromium/src/base/message_loop.cc:356:3
#84 0x7f9902ef02d3 in XRE_InitChildProcess(int, char**, XREChildData const*) /builds/worker/checkouts/gecko/toolkit/xre/nsEmbedFunctions.cpp:739:34
#85 0x561a9c514b39 in content_process_main /builds/worker/checkouts/gecko/browser/app/../../ipc/contentproc/plugin-container.cpp:57:28
#86 0x561a9c514b39 in main /builds/worker/checkouts/gecko/browser/app/nsBrowserApp.cpp:359:18
#87 0x7f9912b30082 in __libc_start_main /build/glibc-SzIz7B/glibc-2.31/csu/../csu/libc-start.c:308:16
#88 0x561a9c4ea8dc in _start (/home/worker/builds/m-c-20220930214439-fuzzing-debug/firefox-bin+0x168dc) (BuildId: aabf37b69b7a7ce8f134f62a18b14c98cbaeb455)

A Pernosco session is available here: https://pernos.co/debug/8UPW7aprqpGB9s9M0eccIw/index.html

Verified bug as reproducible on mozilla-central 20221104160427-510fd2811bcd.
The bug appears to have been introduced in the following build range:

Start: 808c433c77742953dea1f6e0456cd96a505e3615 (20220804044237)
End: 19cb3c811aaecde7e5bcb1826d5e7882f4c9f754 (20220804064605)
Pushlog: https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=808c433c77742953dea1f6e0456cd96a505e3615&tochange=19cb3c811aaecde7e5bcb1826d5e7882f4c9f754

Seems like probably bug 1774704 from that range.

Set release status flags based on info from the regressing bug 1774704

:masayuki, since you are the author of the regressor, bug 1774704, could you take a look? Also, could you set the severity field?

For more information, please visit auto_nag documentation.

Yeah, hitting the assertion is just a bug of the patch for bug 1774704 (forgetting to check whether Selection has at least one range). However, it seems that quitting from the method when Selection does not have a range is also a bug since it may have already touched the DOM tree... Anyway, I'll fix only the regression.

https://searchfox.org/mozilla-central/diff/01966458091b2c66abb1a24e55ebbbc2911d43f1/editor/libeditor/HTMLEditSubActionHandler.cpp#6115

-     if (!SelectionRef().RangeCount() || IsSelectionRangeContainerNotContent()) {
+     if (MOZ_UNLIKELY(!pointToPutCaret.IsSet() && !aRanges.IsInContent())) {
        NS_WARNING("Mutaiton event listener might have changed the selection");
        return NS_ERROR_EDITOR_UNEXPECTED_DOM_TREE;
      }
-     const auto pointToInsertDivElement =
-         GetFirstSelectionStartPoint<EditorDOMPoint>();
+     const EditorDOMPoint pointToInsertDivElement =
+         pointToPutCaret.IsSet() ? pointToPutCaret
+                                 : GetFirstSelectionStartPoint<EditorDOMPoint>();

It still refers Selection via EditorBase::GetFirstRangeStartPoint, however,
it should work with aRanges instead.

Depends on D161422

S3 and we are in RC week, wontfix 106.

https://hg.mozilla.org/mozilla-central/rev/d920e7aa4112

Verified bug as fixed on rev mozilla-central 20221109095836-8baf918fe8e8.
Removing bugmon keyword as no further action possible. Please review the bug and re-add the keyword for further analysis.