This crash was caused by http://trac.webkit.org/changeset/37323. This is already in radar as <rdar://problem/6296129> 00 0029dfac 0110da40 WebKit!JSValueProtect+0x46 [c:\cygwin\home\alice\webkit\opensource\javascriptcore\api\jsvalueref.cpp @ 259] 01 0029dfdc 0110d6a3 Safari!WebViewJSController::controllerLoaded+0x50 [c:\cygwin\home\alice\webkit\internal\safari\win\webviewjscontroller.cpp @ 57] 02 0029dff0 0110db3b Safari!WebViewDialogController::controllerLoaded+0x13 [c:\cygwin\home\alice\webkit\internal\safari\win\webviewdialogcontroller.cpp @ 24] 03 0029e008 70081499 Safari!jsLoaded+0x5b [c:\cygwin\home\alice\webkit\internal\safari\win\webviewjscontroller.cpp @ 72] 04 0029e098 70077422 WebKit!JSC::JSCallbackFunction::call+0xd9 [c:\cygwin\home\alice\webkit\opensource\javascriptcore\api\jscallbackfunction.cpp @ 61] 05 0029e138 700756dd WebKit!JSC::Machine::cti_op_call_NotJSFunction+0xe2 [c:\cygwin\home\alice\webkit\opensource\javascriptcore\vm\machine.cpp @ 4635] 06 0029e174 7007b911 WebKit!JSC::Machine::execute+0x25d [c:\cygwin\home\alice\webkit\opensource\javascriptcore\vm\machine.cpp @ 997] 07 0029e19c 702fcb9c WebKit!JSC::call+0x41 [c:\cygwin\home\alice\webkit\opensource\javascriptcore\kjs\calldata.cpp @ 40] 08 0029e228 700e6ef9 WebKit!WebCore::JSAbstractEventListener::handleEvent+0x1dc [c:\cygwin\home\alice\webkit\opensource\webcore\bindings\js\jseventlistener.cpp @ 98] 09 0029e244 702641ed WebKit!WebCore::Document::handleWindowEvent+0x69 [c:\cygwin\home\alice\webkit\opensource\webcore\dom\document.cpp @ 2723] 0a 0029e25c 70264292 WebKit!WebCore::EventTargetNode::dispatchWindowEvent+0x5d [c:\cygwin\home\alice\webkit\opensource\webcore\dom\eventtargetnode.cpp @ 352] 0b 0029e284 700e47b6 WebKit!WebCore::EventTargetNode::dispatchWindowEvent+0x52 [c:\cygwin\home\alice\webkit\opensource\webcore\dom\eventtargetnode.cpp @ 360] 0c 0029e2a0 70131c23 WebKit!WebCore::Document::implicitClose+0x136 [c:\cygwin\home\alice\webkit\opensource\webcore\dom\document.cpp @ 1590] 0d 0029e2b0 70131a63 WebKit!WebCore::FrameLoader::checkCallImplicitClose+0x63 [c:\cygwin\home\alice\webkit\opensource\webcore\loader\frameloader.cpp @ 1354] 0e 0029e2c0 702f7471 WebKit!WebCore::FrameLoader::checkCompleted+0x83 [c:\cygwin\home\alice\webkit\opensource\webcore\loader\frameloader.cpp @ 1309] 0f 0029e2ec 7039e55b WebKit!WebCore::Loader::Host::didFinishLoading+0xf1 [c:\cygwin\home\alice\webkit\opensource\webcore\loader\loader.cpp @ 308] 10 0029e2f8 703013b7 WebKit!WebCore::SubresourceLoader::didFinishLoading+0x2b [c:\cygwin\home\alice\webkit\opensource\webcore\loader\subresourceloader.cpp @ 196] 11 0029e2fc 7013cd05 WebKit!WebCore::ResourceLoader::didFinishLoading+0x7 [c:\cygwin\home\alice\webkit\opensource\webcore\loader\resourceloader.cpp @ 399] 12 0029e304 70634558 WebKit!WebCore::didFinishLoading+0x15 [c:\cygwin\home\alice\webkit\opensource\webcore\platform\network\cf\resourcehandlecfnet.cpp @ 120]
This was fixed in r38247: http://trac.webkit.org/changeset/37868