This assertion failure is seen with LayoutTests webarchive/loading/object.html and webarchive/loading/missing-data.html (which are already marked as flaky crashes, but this is a new backtrace). ASSERTION FAILED: data /Volumes/Data/slave/sierra-debug/build/Source/WebCore/platform/cf/SharedBufferCF.cpp(71) : void WebCore::SharedBuffer::append(CFDataRef) 1 0x12417497d WTFCrash 2 0x11a8a2dd7 WebCore::SharedBuffer::append(__CFData const*) 3 0x11a8a2d85 WebCore::SharedBuffer::SharedBuffer(__CFData const*) 4 0x11a8a2e5d WebCore::SharedBuffer::SharedBuffer(__CFData const*) 5 0x11a8a2ea6 WebCore::SharedBuffer::create(__CFData const*) 6 0x119e571fe WebCore::LegacyWebArchive::createResource(__CFDictionary const*) 7 0x119e57bfe WebCore::LegacyWebArchive::extract(__CFDictionary const*) 8 0x119e57a25 WebCore::LegacyWebArchive::create(WebCore::URL const&, WebCore::SharedBuffer&) 9 0x1182247cf WTF::RefPtr<WebCore::Archive> WebCore::archiveFactoryCreate<WebCore::LegacyWebArchive>(WebCore::URL const&, WebCore::SharedBuffer&) 10 0x1182241e8 WebCore::ArchiveFactory::create(WebCore::URL const&, WebCore::SharedBuffer*, WTF::String const&) 11 0x1188e5208 WebCore::DocumentLoader::maybeCreateArchive() 12 0x1188e4ef3 WebCore::DocumentLoader::finishedLoading() 13 0x1188e4cad WebCore::DocumentLoader::notifyFinished(WebCore::CachedResource&) 14 0x11838610d WebCore::CachedResource::checkNotify() 15 0x118386381 WebCore::CachedResource::finishLoading(WebCore::SharedBuffer*) 16 0x118380953 WebCore::CachedRawResource::finishLoading(WebCore::SharedBuffer*) 17 0x11aa6ab19 WebCore::SubresourceLoader::didFinishLoading(WebCore::NetworkLoadMetrics const&) 18 0x110128635 WebKit::WebResourceLoader::didFinishResourceLoad(WebCore::NetworkLoadMetrics const&) 19 0x11012d286 void IPC::callMemberFunctionImpl<WebKit::WebResourceLoader, void (WebKit::WebResourceLoader::*)(WebCore::NetworkLoadMetrics const&), std::__1::tuple<WebCore::NetworkLoadMetrics>, 0ul>(WebKit::WebResourceLoader*, void (WebKit::WebResourceLoader::*)(WebCore::NetworkLoadMetrics const&), std::__1::tuple<WebCore::NetworkLoadMetrics>&&, std::__1::integer_sequence<unsigned long, 0ul>) 20 0x11012d0f8 void IPC::callMemberFunction<WebKit::WebResourceLoader, void (WebKit::WebResourceLoader::*)(WebCore::NetworkLoadMetrics const&), std::__1::tuple<WebCore::NetworkLoadMetrics>, std::__1::integer_sequence<unsigned long, 0ul> >(std::__1::tuple<WebCore::NetworkLoadMetrics>&&, WebKit::WebResourceLoader*, void (WebKit::WebResourceLoader::*)(WebCore::NetworkLoadMetrics const&)) 21 0x11012c3d2 void IPC::handleMessage<Messages::WebResourceLoader::DidFinishResourceLoad, WebKit::WebResourceLoader, void (WebKit::WebResourceLoader::*)(WebCore::NetworkLoadMetrics const&)>(IPC::Decoder&, WebKit::WebResourceLoader*, void (WebKit::WebResourceLoader::*)(WebCore::NetworkLoadMetrics const&)) 22 0x11012bb0c WebKit::WebResourceLoader::didReceiveWebResourceLoaderMessage(IPC::Connection&, IPC::Decoder&) 23 0x10f935f69 WebKit::NetworkProcessConnection::didReceiveMessage(IPC::Connection&, IPC::Decoder&) 24 0x10f690b23 IPC::Connection::dispatchMessage(IPC::Decoder&) 25 0x10f686248 IPC::Connection::dispatchMessage(std::__1::unique_ptr<IPC::Decoder, std::__1::default_delete<IPC::Decoder> >) 26 0x10f691120 IPC::Connection::dispatchOneMessage() 27 0x10f6a9d2d IPC::Connection::enqueueIncomingMessage(std::__1::unique_ptr<IPC::Decoder, std::__1::default_delete<IPC::Decoder> >)::$_14::operator()() 28 0x10f6a9c89 WTF::Function<void ()>::CallableWrapper<IPC::Connection::enqueueIncomingMessage(std::__1::unique_ptr<IPC::Decoder, std::__1::default_delete<IPC::Decoder> >)::$_14>::call() 29 0x1241a413e WTF::Function<void ()>::operator()() const 30 0x1241c25cd WTF::RunLoop::performWork() 31 0x1241c2cb4 WTF::RunLoop::performWork(void*) LEAK: 1 WebProcessPool LEAK: 1 WebPageProxy https://build.webkit.org/results/Apple%20Sierra%20Debug%20WK2%20(Tests)/r215807%20(670)/com.apple.WebKit.WebContent.Development-27410-crash-log.txt
This seems to have started with https://trac.webkit.org/changeset/215686/webkit
Created attachment 308310 [details] Patch
http://trac.webkit.org/r215845
*** Bug 171347 has been marked as a duplicate of this bug. ***