We're seeing the following assertion on quite a few WebGL tests here: https://build.webkit.org/results/Apple-iOS-15-Simulator-Debug-WK2-Tests/r291304%20(1950)/results.html ASSERTION FAILED: m_contentsBufferHandle /Volumes/Data/worker/ios-simulator-15-debug/build/Source/WebKit/Shared/RemoteLayerTree/RemoteLayerBackingStore.mm(355) : void WebKit::RemoteLayerBackingStore::paintContents() 1 0x6b2606769 WTFCrash 2 0x694cfbfeb WTFCrashWithInfo(int, char const*, char const*, int) 3 0x6959c727d WebKit::RemoteLayerBackingStore::paintContents() 4 0x695a1e5d7 WebKit::RemoteLayerBackingStoreCollection::paintReachableBackingStoreContents() 5 0x69662609f WebKit::RemoteLayerTreeContext::buildTransaction(WebKit::RemoteLayerTreeTransaction&, WebCore::PlatformCALayer&) 6 0x69529a499 WebKit::RemoteLayerTreeDrawingArea::updateRendering() 7 0x6952a3a0e decltype(*(std::__1::forward<WebKit::RemoteLayerTreeDrawingArea*&>(fp0)).*fp()) std::__1::__invoke<void (WebKit::RemoteLayerTreeDrawingArea::*&)(), WebKit::RemoteLayerTreeDrawingArea*&, void>(void (WebKit::RemoteLayerTreeDrawingArea::*&)(), WebKit::RemoteLayerTreeDrawingArea*&) 8 0x6952a398d std::__1::__bind_return<void (WebKit::RemoteLayerTreeDrawingArea::*)(), std::__1::tuple<WebKit::RemoteLayerTreeDrawingArea*>, std::__1::tuple<>, __is_valid_bind_return<void (WebKit::RemoteLayerTreeDrawingArea::*)(), std::__1::tuple<WebKit::RemoteLayerTreeDrawingArea*>, std::__1::tuple<> >::value>::type std::__1::__apply_functor<void (WebKit::RemoteLayerTreeDrawingArea::*)(), std::__1::tuple<WebKit::RemoteLayerTreeDrawingArea*>, 0ul, std::__1::tuple<> >(void (WebKit::RemoteLayerTreeDrawingArea::*&)(), std::__1::tuple<WebKit::RemoteLayerTreeDrawingArea*>&, std::__1::__tuple_indices<0ul>, std::__1::tuple<>&&) 9 0x6952a3940 std::__1::__bind_return<void (WebKit::RemoteLayerTreeDrawingArea::*)(), std::__1::tuple<WebKit::RemoteLayerTreeDrawingArea*>, std::__1::tuple<>, __is_valid_bind_return<void (WebKit::RemoteLayerTreeDrawingArea::*)(), std::__1::tuple<WebKit::RemoteLayerTreeDrawingArea*>, std::__1::tuple<> >::value>::type std::__1::__bind<void (WebKit::RemoteLayerTreeDrawingArea::*&)(), WebKit::RemoteLayerTreeDrawingArea*>::operator()<>() 10 0x6952a38d9 WTF::Detail::CallableWrapper<std::__1::__bind<void (WebKit::RemoteLayerTreeDrawingArea::*&)(), WebKit::RemoteLayerTreeDrawingArea*>, void>::call() 11 0x694d55fc2 WTF::Function<void ()>::operator()() const 12 0x69529f259 WebCore::Timer::fired() 13 0x6de73bfa6 WebCore::ThreadTimers::sharedTimerFiredInternal() 14 0x6de7468c1 WebCore::ThreadTimers::setSharedTimer(WebCore::SharedTimer*)::$_0::operator()() const 15 0x6de746859 WTF::Detail::CallableWrapper<WebCore::ThreadTimers::setSharedTimer(WebCore::SharedTimer*)::$_0, void>::call() 16 0x6da01e232 WTF::Function<void ()>::operator()() const 17 0x6de6d87e1 WebCore::MainThreadSharedTimer::fired() 18 0x6de7d0276 WebCore::timerFired(__CFRunLoopTimer*, void*) 19 0x7fff2036a6c6 __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__ 20 0x7fff2036a1c2 __CFRunLoopDoTimer 21 0x7fff20369781 __CFRunLoopDoTimers 22 0x7fff20363dc0 __CFRunLoopRun 23 0x7fff20363103 CFRunLoopRunSpecific 24 0x7fff2081941c -[NSRunLoop(NSRunLoop) runMode:beforeDate:] 25 0x7fff20819638 -[NSRunLoop(NSRunLoop) run] 26 0x7fff2006705f _xpc_objc_main 27 0x7fff20069050 xpc_main 28 0x6959c4f3a WebKit::XPCServiceMain(int, char const**) 29 0x697985ecb WKXPCServiceMain 30 0x101e65d12 main 31 0x680001e1e com.apple.WebKit.WebContent.Development terminated (pid 139) because the process crashed
<rdar://problem/90331880>
Regressed between r291190 and r291201
https://trac.webkit.org/log/webkit/trunk?mode=follow_copy&rev=291201&stop_rev=291190 so probably https://trac.webkit.org/changeset/291191/webkit/trunk
Just a bad assertion.
Created attachment 454792 [details] Patch
Created attachment 454794 [details] Patch
Comment on attachment 454794 [details] Patch r=me
Committed r291333 (248472@main): <https://commits.webkit.org/248472@main> All reviewed patches have been landed. Closing bug and clearing flags on attachment 454794 [details].