1746047 - Investigate nsHtml5TreeOpExecutor.cpp 'mOpQueue.IsEmpty()' failed assertion while running browser_ext_browserAction_popup_preload_smoketest.js in debug builds

Status: NEW

(WebExtensions :: Frontend, defect, P3)

Description

[Luca Greco [:rpl] [:luca] [:lgreco]]

As part of Bug 1735899 we are introducing a new mochitest that covers the underlying issue (and the fix landed in Firefox 95) in automation.

Unfortunately we have to skip it on debug builds because of an assertion failure that the test seems to be able to trigger (and which suggests there may be some other race, which shares the STR of Bug 1735899, which may not be introducing any visible regression and may have not been identified yet).

This bug is meant to track additional investigation of this assertion failure:

[Child 2189419, Main Thread] ###!!! ASSERTION: Somehow there's stuff in the op queue.: 'mOpQueue.IsEmpty()', 
     file /builds/worker/checkouts/gecko/parser/html/nsHtml5TreeOpExecutor.cpp:144
#01: NS_DebugBreak [xpcom/base/nsDebugImpl.cpp:429]
#02: nsHtml5TreeOpExecutor::~nsHtml5TreeOpExecutor() [parser/html/nsHtml5TreeOpExecutor.cpp:145]
#03: nsHtml5TreeOpExecutor::~nsHtml5TreeOpExecutor() [parser/html/nsHtml5TreeOpExecutor.cpp:131]
#04: SnowWhiteKiller::MaybeKillObject(SnowWhiteKiller::SnowWhiteObject&) [xpcom/base/nsCycleCollector.cpp:2419]
#05: SnowWhiteKiller::Visit(nsPurpleBuffer&, nsPurpleBufferEntry*) [xpcom/base/nsCycleCollector.cpp:2444]
#06: void nsPurpleBuffer::VisitEntries<SnowWhiteKiller>(SnowWhiteKiller&) [xpcom/base/nsCycleCollector.cpp:939]
#07: nsCycleCollector::FreeSnowWhiteWithBudget(js::SliceBudget&) [xpcom/base/nsCycleCollector.cpp:2613]
#08: AsyncFreeSnowWhite::Run() [js/xpconnect/src/XPCJSRuntime.cpp:149]
#09: IdleRunnableWrapper::Run() [xpcom/threads/nsThreadUtils.cpp:311]
#10: mozilla::RunnableTask::Run() [xpcom/threads/TaskController.cpp:469]