Found while fuzzing m-c 20231122-ef0b50d89a7f (--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: aRange.StartRef().IsSet(), at /builds/worker/checkouts/gecko/editor/libeditor/HTMLStyleEditor.cpp:2922

#0 0x7f84c6fe15b4 in mozilla::HTMLEditor::GetExtendedRangeWrappingEntirelySelectedElements(mozilla::EditorDOMRangeBase<mozilla::EditorDOMPointBase<nsINode*, nsIContent*>> const&) const /builds/worker/checkouts/gecko/editor/libeditor/HTMLStyleEditor.cpp:2925:3
#1 0x7f84c6fcda93 in mozilla::HTMLEditor::RemoveInlinePropertiesAsSubAction(nsTArray<mozilla::EditorInlineStyle> const&) /builds/worker/checkouts/gecko/editor/libeditor/HTMLStyleEditor.cpp:3431:17
#2 0x7f84c6fe31d1 in mozilla::HTMLEditor::RemoveInlinePropertyAsAction(nsStaticAtom&, nsStaticAtom*, nsIPrincipal*) /builds/worker/checkouts/gecko/editor/libeditor/HTMLStyleEditor.cpp:3277:8
#3 0x7f84c6f626f2 in mozilla::StyleUpdatingCommand::ToggleState(nsStaticAtom&, mozilla::HTMLEditor&, nsIPrincipal*) const /builds/worker/checkouts/gecko/editor/libeditor/HTMLEditorCommands.cpp:202:21
#4 0x7f84c6f611ff in mozilla::StateUpdatingCommandBase::DoCommand(mozilla::Command, mozilla::EditorBase&, nsIPrincipal*) const /builds/worker/checkouts/gecko/editor/libeditor/HTMLEditorCommands.cpp:75:17
#5 0x7f84c3496ef7 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:5528:37
#6 0x7f84c4672f71 in mozilla::dom::Document_Binding::execCommand(JSContext*, JS::Handle<JSObject*>, void*, JSJitMethodCallArgs const&) /builds/worker/workspace/obj-build/dom/bindings/./DocumentBinding.cpp:4039:36
#7 0x7f84c499a0ee 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:3258:13
#8 0x7f84c8eab9f4 in CallJSNative(JSContext*, bool (*)(JSContext*, unsigned int, JS::Value*), js::CallReason, JS::CallArgs const&) /builds/worker/checkouts/gecko/js/src/vm/Interpreter.cpp:479:13
#9 0x7f84c8eab34b in js::InternalCallOrConstruct(JSContext*, JS::CallArgs const&, js::MaybeConstruct, js::CallReason) /builds/worker/checkouts/gecko/js/src/vm/Interpreter.cpp:573:12
#10 0x7f84c8ebac48 in CallFromStack /builds/worker/checkouts/gecko/js/src/vm/Interpreter.cpp:645:10
#11 0x7f84c8ebac48 in js::Interpret(JSContext*, js::RunState&) /builds/worker/checkouts/gecko/js/src/vm/Interpreter.cpp:3060:16
#12 0x7f84c8eaa8d2 in js::RunScript(JSContext*, js::RunState&) /builds/worker/checkouts/gecko/js/src/vm/Interpreter.cpp:451:13
#13 0x7f84c8eab368 in js::InternalCallOrConstruct(JSContext*, JS::CallArgs const&, js::MaybeConstruct, js::CallReason) /builds/worker/checkouts/gecko/js/src/vm/Interpreter.cpp:605:13
#14 0x7f84c8eac61d 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:672:8
#15 0x7f84c8f9e634 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:119:10
#16 0x7f84c46cf58b 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
#17 0x7f84c5034589 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
#18 0x7f84c5033657 in mozilla::JSEventHandler::HandleEvent(mozilla::dom::Event*) /builds/worker/checkouts/gecko/dom/events/JSEventHandler.cpp:199:12
#19 0x7f84c500ff25 in mozilla::EventListenerManager::HandleEventSingleListener(mozilla::EventListenerManager::Listener*, nsAtom*, mozilla::WidgetEvent*, mozilla::dom::Event*, mozilla::dom::EventTarget*, bool) /builds/worker/checkouts/gecko/dom/events/EventListenerManager.cpp:1348:22
#20 0x7f84c5011024 in mozilla::EventListenerManager::HandleEventWithListenerArray(mozilla::EventListenerManager::ListenerArray*, nsAtom*, mozilla::EventMessage, nsPresContext*, mozilla::WidgetEvent*, mozilla::dom::Event**, mozilla::dom::EventTarget*, bool) /builds/worker/checkouts/gecko/dom/events/EventListenerManager.cpp:1663:12
#21 0x7f84c5010899 in mozilla::EventListenerManager::HandleEventInternal(nsPresContext*, mozilla::WidgetEvent*, mozilla::dom::Event**, mozilla::dom::EventTarget*, nsEventStatus*, bool) /builds/worker/checkouts/gecko/dom/events/EventListenerManager.cpp:1560:35
#22 0x7f84c5003fbf in HandleEvent /builds/worker/workspace/obj-build/dist/include/mozilla/EventListenerManager.h:465:5
#23 0x7f84c5003fbf in mozilla::EventTargetChainItem::HandleEvent(mozilla::EventChainPostVisitor&, mozilla::ELMCreationDetector&) /builds/worker/checkouts/gecko/dom/events/EventDispatcher.cpp:364:17
#24 0x7f84c500353b in mozilla::EventTargetChainItem::HandleEventTargetChain(nsTArray<mozilla::EventTargetChainItem>&, mozilla::EventChainPostVisitor&, mozilla::EventDispatchingCallback*, mozilla::ELMCreationDetector&) /builds/worker/checkouts/gecko/dom/events/EventDispatcher.cpp:611:18
#25 0x7f84c5005f76 in mozilla::EventDispatcher::Dispatch(mozilla::dom::EventTarget*, nsPresContext*, mozilla::WidgetEvent*, mozilla::dom::Event*, nsEventStatus*, mozilla::EventDispatchingCallback*, nsTArray<mozilla::dom::EventTarget*>*) /builds/worker/checkouts/gecko/dom/events/EventDispatcher.cpp:1232:11
#26 0x7f84c7203ad2 in nsDocumentViewer::LoadComplete(nsresult) /builds/worker/checkouts/gecko/layout/base/nsDocumentViewer.cpp:1077:7
#27 0x7f84c8490002 in nsDocShell::EndPageLoad(nsIWebProgress*, nsIChannel*, nsresult) /builds/worker/checkouts/gecko/docshell/base/nsDocShell.cpp:6329:13
#28 0x7f84c848f40b in nsDocShell::OnStateChange(nsIWebProgress*, nsIRequest*, unsigned int, nsresult) /builds/worker/checkouts/gecko/docshell/base/nsDocShell.cpp:5721:7
#29 0x7f84c84910d6 in non-virtual thunk to nsDocShell::OnStateChange(nsIWebProgress*, nsIRequest*, unsigned int, nsresult) /builds/worker/checkouts/gecko/docshell/base/nsDocShell.cpp
#30 0x7f84c287a4c9 in nsDocLoader::DoFireOnStateChange(nsIWebProgress*, nsIRequest*, int&, nsresult) /builds/worker/checkouts/gecko/uriloader/base/nsDocLoader.cpp:1372:3
#31 0x7f84c2879a42 in nsDocLoader::doStopDocumentLoad(nsIRequest*, nsresult) /builds/worker/checkouts/gecko/uriloader/base/nsDocLoader.cpp:978:14
#32 0x7f84c2877c4b in nsDocLoader::DocLoaderIsEmpty(bool, mozilla::Maybe<nsresult> const&) /builds/worker/checkouts/gecko/uriloader/base/nsDocLoader.cpp:795:9
#33 0x7f84c2878ef1 in nsDocLoader::OnStopRequest(nsIRequest*, nsresult) /builds/worker/checkouts/gecko/uriloader/base/nsDocLoader.cpp:678:5
#34 0x7f84c84c773f in nsDocShell::OnStopRequest(nsIRequest*, nsresult) /builds/worker/checkouts/gecko/docshell/base/nsDocShell.cpp:13839:23
#35 0x7f84c1a8dbdf in mozilla::net::nsLoadGroup::NotifyRemovalObservers(nsIRequest*, nsresult) /builds/worker/checkouts/gecko/netwerk/base/nsLoadGroup.cpp:631:22
#36 0x7f84c1a8f120 in mozilla::net::nsLoadGroup::RemoveRequest(nsIRequest*, nsISupports*, nsresult) /builds/worker/checkouts/gecko/netwerk/base/nsLoadGroup.cpp:535:10
#37 0x7f84c34c41dc in mozilla::dom::Document::DoUnblockOnload() /builds/worker/checkouts/gecko/dom/base/Document.cpp:11688:18
#38 0x7f84c34aa176 in mozilla::dom::Document::DispatchContentLoadedEvents() /builds/worker/checkouts/gecko/dom/base/Document.cpp:8157:3
#39 0x7f84c355e0d9 in operator()<> /builds/worker/workspace/obj-build/dist/include/nsThreadUtils.h:1164:18
#40 0x7f84c355e0d9 in __invoke_impl<void, (lambda at /builds/worker/workspace/obj-build/dist/include/nsThreadUtils.h:1163:9)> /builds/worker/fetches/sysroot-x86_64-linux-gnu/usr/lib/gcc/x86_64-linux-gnu/8/../../../../include/c++/8/bits/invoke.h:60:14
#41 0x7f84c355e0d9 in __invoke<(lambda at /builds/worker/workspace/obj-build/dist/include/nsThreadUtils.h:1163:9)> /builds/worker/fetches/sysroot-x86_64-linux-gnu/usr/lib/gcc/x86_64-linux-gnu/8/../../../../include/c++/8/bits/invoke.h:95:14
#42 0x7f84c355e0d9 in __apply_impl<(lambda at /builds/worker/workspace/obj-build/dist/include/nsThreadUtils.h:1163:9), std::tuple<> &> /builds/worker/fetches/sysroot-x86_64-linux-gnu/usr/lib/gcc/x86_64-linux-gnu/8/../../../../include/c++/8/tuple:1678:14
#43 0x7f84c355e0d9 in apply<(lambda at /builds/worker/workspace/obj-build/dist/include/nsThreadUtils.h:1163:9), std::tuple<> &> /builds/worker/fetches/sysroot-x86_64-linux-gnu/usr/lib/gcc/x86_64-linux-gnu/8/../../../../include/c++/8/tuple:1687:14
#44 0x7f84c355e0d9 in apply<mozilla::dom::Document, void (mozilla::dom::Document::*)()> /builds/worker/workspace/obj-build/dist/include/nsThreadUtils.h:1162:12
#45 0x7f84c355e0d9 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:1213:13
#46 0x7f84c1849337 in mozilla::RunnableTask::Run() /builds/worker/checkouts/gecko/xpcom/threads/TaskController.cpp:568:16
#47 0x7f84c183eaa6 in mozilla::TaskController::DoExecuteNextTaskOnlyMainThreadInternal(mozilla::detail::BaseAutoLock<mozilla::Mutex&> const&) /builds/worker/checkouts/gecko/xpcom/threads/TaskController.cpp:895:26
#48 0x7f84c183d287 in mozilla::TaskController::ExecuteNextTaskOnlyMainThreadInternal(mozilla::detail::BaseAutoLock<mozilla::Mutex&> const&) /builds/worker/checkouts/gecko/xpcom/threads/TaskController.cpp:718:15
#49 0x7f84c183d705 in mozilla::TaskController::ProcessPendingMTTask(bool) /builds/worker/checkouts/gecko/xpcom/threads/TaskController.cpp:504:36
#50 0x7f84c184d2d6 in operator() /builds/worker/checkouts/gecko/xpcom/threads/TaskController.cpp:222:37
#51 0x7f84c184d2d6 in mozilla::detail::RunnableFunction<mozilla::TaskController::TaskController()::$_0>::Run() /builds/worker/checkouts/gecko/xpcom/threads/nsThreadUtils.h:548:5
#52 0x7f84c1862642 in nsThread::ProcessNextEvent(bool, bool*) /builds/worker/checkouts/gecko/xpcom/threads/nsThread.cpp:1199:16
#53 0x7f84c186978d in NS_ProcessNextEvent(nsIThread*, bool) /builds/worker/checkouts/gecko/xpcom/threads/nsThreadUtils.cpp:480:10
#54 0x7f84c253c9a5 in mozilla::ipc::MessagePump::Run(base::MessagePump::Delegate*) /builds/worker/checkouts/gecko/ipc/glue/MessagePump.cpp:85:21
#55 0x7f84c2456471 in RunHandler /builds/worker/checkouts/gecko/ipc/chromium/src/base/message_loop.cc:363:3
#56 0x7f84c2456471 in MessageLoop::Run() /builds/worker/checkouts/gecko/ipc/chromium/src/base/message_loop.cc:345:3
#57 0x7f84c6d815b8 in nsBaseAppShell::Run() /builds/worker/checkouts/gecko/widget/nsBaseAppShell.cpp:148:27
#58 0x7f84c6e3e588 in nsAppShell::Run() /builds/worker/checkouts/gecko/widget/gtk/nsAppShell.cpp:470:33
#59 0x7f84c8c71cbb in XRE_RunAppShell() /builds/worker/checkouts/gecko/toolkit/xre/nsEmbedFunctions.cpp:721:20
#60 0x7f84c253d886 in mozilla::ipc::MessagePumpForChildProcess::Run(base::MessagePump::Delegate*) /builds/worker/checkouts/gecko/ipc/glue/MessagePump.cpp:235:9
#61 0x7f84c2456471 in RunHandler /builds/worker/checkouts/gecko/ipc/chromium/src/base/message_loop.cc:363:3
#62 0x7f84c2456471 in MessageLoop::Run() /builds/worker/checkouts/gecko/ipc/chromium/src/base/message_loop.cc:345:3
#63 0x7f84c8c71522 in XRE_InitChildProcess(int, char**, XREChildData const*) /builds/worker/checkouts/gecko/toolkit/xre/nsEmbedFunctions.cpp:656:34
#64 0x55d78038b156 in content_process_main /builds/worker/checkouts/gecko/browser/app/../../ipc/contentproc/plugin-container.cpp:57:28
#65 0x55d78038b156 in main /builds/worker/checkouts/gecko/browser/app/nsBrowserApp.cpp:375:18
#66 0x7f84d5e29d8f in __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58:16
#67 0x7f84d5e29e3f in __libc_start_main csu/../csu/libc-start.c:392:3
#68 0x55d780360e88 in _start (/home/user/workspace/browsers/m-c-20231229205714-fuzzing-debug/firefox-bin+0x58e88) (BuildId: 5f307722611ed43ee5f9e3e1fd0314e185bd83a6)

Verified bug as reproducible on mozilla-central 20231229205714-52b5c5b51719.
The bug appears to have been introduced in the following build range:

Start: 1634cff61cb0e270b9660ebdc234cfcf3fed2c68 (20230618205154)
End: 1c059369d43547f90439b0a44cc76b54a0a3af97 (20230619003235)
Pushlog: https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=1634cff61cb0e270b9660ebdc234cfcf3fed2c68&tochange=1c059369d43547f90439b0a44cc76b54a0a3af97

Set release status flags based on info from the regressing bug 1821799

:masayuki, since you are the author of the regressor, bug 1821799, could you take a look? Also, could you set the severity field?

For more information, please visit BugBot documentation.

It seems that the assertion detects a bug of multi-range selection handling.

Testcase crashes using the initial build (mozilla-central 20240308161250-fe38c21e5d5b) but not with tip (mozilla-central 20250307214355-99620432e3b8.)

The bug appears to have been fixed in the following build range:

Start: 9d547b90a4073f5906b1220472f69fbc2fdff928 (20250305042859)
End: b00d78bcd328cf80893a4725b8664db65d8fdf10 (20250304235021)
Pushlog: https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=9d547b90a4073f5906b1220472f69fbc2fdff928&tochange=b00d78bcd328cf80893a4725b8664db65d8fdf10

tsmith, can you confirm that the above bisection range is responsible for fixing this issue?
Removing bugmon keyword as no further action possible. Please review the bug and re-add the keyword for further analysis.

It's temporarily not reproducible in the nightly channel due to bug 1951772, but it'll restart to crash once I land bug 1952410.