Created attachment 243681 [details] Crash log (happens for multiple tests). I'm noticing a number of crashes on Windows with the attached crash trace. BUGCHECK_STR: APPLICATION_FAULT_ACTIONABLE_HEAP_CORRUPTION_heap_failure_block_not_busy_DOUBLE_FREE_AFTER_CALL PRIMARY_PROBLEM_CLASS: ACTIONABLE_HEAP_CORRUPTION_heap_failure_block_not_busy_AFTER_CALL DEFAULT_BUCKET_ID: ACTIONABLE_HEAP_CORRUPTION_heap_failure_block_not_busy_AFTER_CALL web STACK_TEXT: 7731c370 7729e6de ntdll!RtlFreeHeap+0x4160f 7731c374 02b5dd4a webkit!free+0x1a 7731c378 021bda5d webkit!WebMutableURLRequest::Release+0x1d 7731c37c 021a4377 webkit!WebFrameLoaderClient::dispatchDecidePolicyForNavigationAction+0x137 7731c380 02a00316 webkit!WebCore::PolicyChecker::checkNavigationPolicy+0x226 7731c384 0252a73a webkit!WebCore::FrameLoader::loadWithDocumentLoader+0x2fa 7731c388 0252a883 webkit!WebCore::FrameLoader::load+0xd3 7731c38c 02523eec webkit!WebCore::FrameLoader::load+0x19c 7731c390 021b12d5 webkit!WebFrame::loadRequest+0x95 7731c394 10015ac6 dumprendertree!runTest+0x526 7731c398 10016550 dumprendertree!main+0x5d0 7731c39c 100166ce dumprendertree!dllLauncherEntryPoint+0xe 7731c3a0 00401c35 dumprendertree!main+0x4b5 7731c3a4 004042f9 dumprendertree!__tmainCRTStartup+0xfe 7731c3a8 7527919f kernel32!BaseThreadInitThunk+0xe 7731c3ac 77270bbb ntdll!__RtlUserThreadStart+0x20 7731c3b0 77270b91 ntdll!_RtlUserThreadStart+0x1b
<rdar://problem/19337515>
This was resolved by the _variant_t work in Bug 139906. Landed in r178669: <http://trac.webkit.org/changeset/178669>.