Don't assume AccessibleObjectFromEvent succeeds

Fixes <http://webkit.org/b/44136> <rdar://problem/8321684> Crash in
DumpRenderTree!notificationListenerProc when running
plugins/access-after-page-destroyed.html

Reviewed by Sam Weinig.

* DumpRenderTree/win/AccessibilityControllerWin.cpp:
(notificationListenerProc): Check both the return value of
AccessibleObjectFromEvent and the object it returns, as MSDN
recommends.

Canonical link: https://commits.webkit.org/59535@main
git-svn-id: https://svn.webkit.org/repository/webkit/trunk@68907 268f45cc-cd09-0410-ab3c-d52691b4dbfc

WebKitTools/ChangeLog

@@ -1,3 +1,18 @@
+2010-10-01  Adam Roben  <aroben@apple.com>
+
+        Don't assume AccessibleObjectFromEvent succeeds
+
+        Fixes <http://webkit.org/b/44136> <rdar://problem/8321684> Crash in
+        DumpRenderTree!notificationListenerProc when running
+        plugins/access-after-page-destroyed.html
+
+        Reviewed by Sam Weinig.
+
+        * DumpRenderTree/win/AccessibilityControllerWin.cpp:
+        (notificationListenerProc): Check both the return value of
+        AccessibleObjectFromEvent and the object it returns, as MSDN
+        recommends.
+
 2010-10-01  Gabor Rapcsanyi  <rgabor@inf.u-szeged.hu>
 
         Reviewed by Tony Chang.

WebKitTools/DumpRenderTree/win/AccessibilityControllerWin.cpp

@@ -232,7 +232,8 @@ static void CALLBACK notificationListenerProc(HWINEVENTHOOK, DWORD event, HWND h
     VariantInit(&vChild);
 
     HRESULT hr = AccessibleObjectFromEvent(hwnd, idObject, idChild, &parentObject, &vChild);
-    ASSERT(SUCCEEDED(hr));
+    if (FAILED(hr) || !parentObject)
+        return;
 
     COMPtr<IDispatch> childDispatch;
     if (FAILED(parentObject->get_accChild(vChild, &childDispatch))) {