Bug 239710

I don't know how to reproduce the assertion failure, but I observed it by browsing some sites.
WinCairo WK2 Debug build r293306

ASSERTION FAILED: m_subresourceLoaders.isEmpty()
C:\home\webkit\gb\Source\WebCore\loader/DocumentLoader.cpp(1920) : WebCore::DocumentLoader::stopLoadingSubresources


WTF.dll!WTFCrash() Line 322	C++
WebKit2.dll!WTFCrashWithInfo(int __formal, const char * __formal, const char * __formal, int __formal) Line 749	C++
WebKit2.dll!WebCore::DocumentLoader::stopLoadingSubresources() Line 1920	C++
WebKit2.dll!WebCore::DocumentLoader::stopLoading() Line 404	C++
WebKit2.dll!WebCore::FrameLoader::stopAllLoaders(WebCore::ClearProvisionalItem clearProvisionalItem, WebCore::StopLoadingPolicy stopLoadingPolicy) Line 1832	C++
WebKit2.dll!WebCore::FrameLoader::continueLoadAfterNavigationPolicy(const WebCore::ResourceRequest & request, WebCore::FormState * formState, WebCore::NavigationPolicyDecision navigationPolicyDecision, WebCore::AllowNavigationToInvalidURL allowNavigationToInvalidURL) Line 3516	C++
WebKit2.dll!`WebCore::FrameLoader::loadWithDocumentLoader'::`2'::<lambda_2>::operator()(const WebCore::ResourceRequest & request, WTF::WeakPtr<WebCore::FormState,WTF::EmptyCounter> && formState, WebCore::NavigationPolicyDecision navigationPolicyDecision) Line 1637	C++
WebKit2.dll!WTF::Detail::CallableWrapper<`WebCore::FrameLoader::loadWithDocumentLoader'::`2'::<lambda_2>,void,WebCore::ResourceRequest &&,WTF::WeakPtr<WebCore::FormState,WTF::EmptyCounter> &&,enum WebCore::NavigationPolicyDecision>::call(WebCore::ResourceRequest && <in_0>, WTF::WeakPtr<WebCore::FormState,WTF::EmptyCounter> && <in_1>, WebCore::NavigationPolicyDecision <in_2>) Line 53	C++
WebKit2.dll!WTF::Function<void __cdecl(WebCore::ResourceRequest &&,WTF::WeakPtr<WebCore::FormState,WTF::EmptyCounter> &&,enum WebCore::NavigationPolicyDecision)>::operator()(WebCore::ResourceRequest && <in_0>, WTF::WeakPtr<WebCore::FormState,WTF::EmptyCounter> && <in_1>, WebCore::NavigationPolicyDecision <in_2>) Line 83	C++
WebKit2.dll!WTF::CompletionHandler<void __cdecl(WebCore::ResourceRequest &&,WTF::WeakPtr<WebCore::FormState,WTF::EmptyCounter> &&,enum WebCore::NavigationPolicyDecision)>::operator()(WebCore::ResourceRequest && <in_0>, WTF::WeakPtr<WebCore::FormState,WTF::EmptyCounter> && <in_1>, WebCore::NavigationPolicyDecision <in_2>) Line 72	C++
WebKit2.dll!`WebCore::FrameLoader::PolicyChecker::checkNavigationPolicy'::`2'::<lambda_1>::operator()(WebCore::PolicyAction policyAction, WebCore::PolicyCheckIdentifier responseIdentifier) Line 239	C++
WebKit2.dll!WTF::Detail::CallableWrapper<`WebCore::FrameLoader::PolicyChecker::checkNavigationPolicy'::`2'::<lambda_1>,void,enum WebCore::PolicyAction,WebCore::PolicyCheckIdentifier>::call(WebCore::PolicyAction <in_0>, WebCore::PolicyCheckIdentifier <in_1>) Line 53	C++
WebKit2.dll!WTF::Function<void __cdecl(enum WebCore::PolicyAction,WebCore::PolicyCheckIdentifier)>::operator()(WebCore::PolicyAction <in_0>, WebCore::PolicyCheckIdentifier <in_1>) Line 83	C++
WebKit2.dll!WebKit::WebFrame::didReceivePolicyDecision(unsigned __int64 listenerID, WebKit::PolicyDecision && policyDecision) Line 285	C++
WebKit2.dll!WebKit::WebPage::didReceivePolicyDecision(WTF::ObjectIdentifier<enum WebCore::FrameIdentifierType> frameID, unsigned __int64 listenerID, WebKit::PolicyDecision && policyDecision, const WTF::Vector<WebKit::SandboxExtension::Handle,0,WTF::CrashOnOverflow,16,WTF::FastMalloc> & networkExtensionsHandles) Line 3671	C++
WebKit2.dll!IPC::callMemberFunctionImpl<WebKit::WebPage,void (__cdecl WebKit::WebPage::*)(WTF::ObjectIdentifier<enum WebCore::FrameIdentifierType>,unsigned __int64,WebKit::PolicyDecision &&,WTF::Vector<WebKit::SandboxExtension::Handle,0,WTF::CrashOnOverflow,16,WTF::FastMalloc> const &),std::tuple<WTF::ObjectIdentifier<enum WebCore::FrameIdentifierType>,unsigned __int64,WebKit::PolicyDecision,WTF::Vector<WebKit::SandboxExtension::Handle,0,WTF::CrashOnOverflow,16,WTF::FastMalloc>>,0,1,2,3>(WebKit::WebPage * object, void(WebKit::WebPage::*)(WTF::ObjectIdentifier<enum WebCore::FrameIdentifierType>, unsigned __int64, WebKit::PolicyDecision &&, const WTF::Vector<WebKit::SandboxExtension::Handle,0,WTF::CrashOnOverflow,16,WTF::FastMalloc> &) function, std::tuple<WTF::ObjectIdentifier<enum WebCore::FrameIdentifierType>,unsigned __int64,WebKit::PolicyDecision,WTF::Vector<WebKit::SandboxExtension::Handle,0,WTF::CrashOnOverflow,16,WTF::FastMalloc>> && args, std::integer_sequence<unsigned __int64,0,1,2,3> __formal) Line 126	C++
WebKit2.dll!IPC::callMemberFunction<WebKit::WebPage,void (__cdecl WebKit::WebPage::*)(WTF::ObjectIdentifier<enum WebCore::FrameIdentifierType>,unsigned __int64,WebKit::PolicyDecision &&,WTF::Vector<WebKit::SandboxExtension::Handle,0,WTF::CrashOnOverflow,16,WTF::FastMalloc> const &),std::tuple<WTF::ObjectIdentifier<enum WebCore::FrameIdentifierType>,unsigned __int64,WebKit::PolicyDecision,WTF::Vector<WebKit::SandboxExtension::Handle,0,WTF::CrashOnOverflow,16,WTF::FastMalloc>>,std::integer_sequence<unsigned __int64,0,1,2,3>>(std::tuple<WTF::ObjectIdentifier<enum WebCore::FrameIdentifierType>,unsigned __int64,WebKit::PolicyDecision,WTF::Vector<WebKit::SandboxExtension::Handle,0,WTF::CrashOnOverflow,16,WTF::FastMalloc>> && args, WebKit::WebPage * object, void(WebKit::WebPage::*)(WTF::ObjectIdentifier<enum WebCore::FrameIdentifierType>, unsigned __int64, WebKit::PolicyDecision &&, const WTF::Vector<WebKit::SandboxExtension::Handle,0,WTF::CrashOnOverflow,16,WTF::FastMalloc> &) function) Line 132	C++
WebKit2.dll!IPC::handleMessage<Messages::WebPage::DidReceivePolicyDecision,WebKit::WebPage,void (__cdecl WebKit::WebPage::*)(WTF::ObjectIdentifier<enum WebCore::FrameIdentifierType>,unsigned __int64,WebKit::PolicyDecision &&,WTF::Vector<WebKit::SandboxExtension::Handle,0,WTF::CrashOnOverflow,16,WTF::FastMalloc> const &)>(IPC::Connection & connection, IPC::Decoder & decoder, WebKit::WebPage * object, void(WebKit::WebPage::*)(WTF::ObjectIdentifier<enum WebCore::FrameIdentifierType>, unsigned __int64, WebKit::PolicyDecision &&, const WTF::Vector<WebKit::SandboxExtension::Handle,0,WTF::CrashOnOverflow,16,WTF::FastMalloc> &) function) Line 254	C++
WebKit2.dll!WebKit::WebPage::didReceiveWebPageMessage(IPC::Connection & connection, IPC::Decoder & decoder) Line 2889	C++
WebKit2.dll!WebKit::WebPage::didReceiveMessage(IPC::Connection & connection, IPC::Decoder & decoder) Line 5309	C++
WebKit2.dll!IPC::MessageReceiverMap::dispatchMessage(IPC::Connection & connection, IPC::Decoder & decoder) Line 130	C++
WebKit2.dll!WebKit::WebProcess::didReceiveMessage(IPC::Connection & connection, IPC::Decoder & decoder) Line 914	C++
WebKit2.dll!IPC::Connection::dispatchMessage(IPC::Decoder & decoder) Line 1109	C++
WebKit2.dll!IPC::Connection::dispatchMessage(std::unique_ptr<IPC::Decoder,std::default_delete<IPC::Decoder>> message) Line 1155	C++
WebKit2.dll!IPC::Connection::dispatchOneIncomingMessage() Line 1223	C++
WebKit2.dll!`IPC::Connection::enqueueIncomingMessage'::`2'::<lambda_1>::operator()() Line 1073	C++
WebKit2.dll!WTF::Detail::CallableWrapper<`IPC::Connection::enqueueIncomingMessage'::`2'::<lambda_1>,void>::call() Line 53	C++
WTF.dll!WTF::Function<void __cdecl(void)>::operator()() Line 83	C++
WTF.dll!WTF::RunLoop::performWork() Line 134	C++
WTF.dll!WTF::RunLoop::wndProc(HWND__ * hWnd, unsigned int message, unsigned __int64 wParam, __int64 lParam) Line 57	C++
WTF.dll!WTF::RunLoop::RunLoopWndProc(HWND__ * hWnd, unsigned int message, unsigned __int64 wParam, __int64 lParam) Line 39	C++
[External Code]	
WTF.dll!WTF::RunLoop::run() Line 74	C++
WebKit2.dll!WebKit::AuxiliaryProcessMainBase<WebKit::WebProcess,1>::run(int argc, char * * argv) Line 71	C++
WebKit2.dll!WebKit::AuxiliaryProcessMain<WebKit::WebProcessMainWin>(int argc, char * * argv) Line 97	C++
WebKit2.dll!WebKit::WebProcessMain(int argc, char * * argv) Line 58	C++
WebKitWebProcess.exe!main(int argc, char * * argv) Line 35	C++
[External Code]