mshtml: Don't share nsstyle reference with nsnode.

dlls/mshtml/htmlstyleelem.c

@@ -319,13 +319,44 @@ static void HTMLStyleElement_destructor(HTMLDOMNode *iface)
     HTMLElement_destructor(iface);
 }
 
+static void HTMLStyleElement_traverse(HTMLDOMNode *iface, nsCycleCollectionTraversalCallback *cb)
+{
+    HTMLStyleElement *This = impl_from_HTMLDOMNode(iface);
+
+    if(This->nsstyle)
+        note_cc_edge((nsISupports*)This->nsstyle, "This->nsstyle", cb);
+}
+
+static void HTMLStyleElement_unlink(HTMLDOMNode *iface)
+{
+    HTMLStyleElement *This = impl_from_HTMLDOMNode(iface);
+
+    if(This->nsstyle) {
+        nsIDOMHTMLStyleElement *nsstyle = This->nsstyle;
+
+        This->nsstyle = NULL;
+        nsIDOMHTMLStyleElement_Release(nsstyle);
+    }
+}
+
 static const NodeImplVtbl HTMLStyleElementImplVtbl = {
     HTMLStyleElement_QI,
     HTMLStyleElement_destructor,
     HTMLElement_cpc,
     HTMLElement_clone,
     HTMLElement_handle_event,
-    HTMLElement_get_attr_col
+    HTMLElement_get_attr_col,
+    NULL,
+    NULL,
+    NULL,
+    NULL,
+    NULL,
+    NULL,
+    NULL,
+    NULL,
+    NULL,
+    HTMLStyleElement_traverse,
+    HTMLStyleElement_unlink
 };
 
 static const tid_t HTMLStyleElement_iface_tids[] = {
@@ -355,10 +386,7 @@ HRESULT HTMLStyleElement_Create(HTMLDocumentNode *doc, nsIDOMHTMLElement *nselem
     HTMLElement_Init(&ret->element, doc, nselem, &HTMLStyleElement_dispex);
 
     nsres = nsIDOMHTMLElement_QueryInterface(nselem, &IID_nsIDOMHTMLStyleElement, (void**)&ret->nsstyle);
-
-    /* Share nsstyle reference with nsnode */
-    assert(nsres == NS_OK && (nsIDOMNode*)ret->nsstyle == ret->element.node.nsnode);
-    nsIDOMNode_Release(ret->element.node.nsnode);
+    assert(nsres == NS_OK);
 
     *elem = &ret->element;
     return S_OK;