Index: window.c
===================================================================
--- window.c	(revision 65084)
+++ window.c	(working copy)
@@ -1992,6 +1992,13 @@
     ParentWindow = hWndParent ? UserGetWindowObject(hWndParent): NULL;
     OwnerWindow = hWndOwner ? UserGetWindowObject(hWndOwner): NULL;

+    if (ParentWindow == NULL && (Cs->style & (WS_CHILD|WS_POPUP)) == WS_CHILD)
+    {
+         ERR("Cannot create a child window with a destroyed parent!\n");
+         EngSetLastError(ERROR_TLW_WITH_WSCHILD);
+         goto cleanup;
+    }
+
     /* FIXME: Is this correct? */
     if(OwnerWindow)
         OwnerWindow = UserGetAncestor(OwnerWindow, GA_ROOT);