More IsNodeOfType. Bug 336822, r+sr=sicking

dom/src/base/nsDOMClassInfo.cpp

@@ -6416,21 +6416,16 @@ NS_IMETHODIMP
 nsNodeSH::PreCreate(nsISupports *nativeObj, JSContext *cx, JSObject *globalObj,
                     JSObject **parentObj)
 {
-  nsCOMPtr<nsIContent> content(do_QueryInterface(nativeObj));
-  nsCOMPtr<nsIDocument> doc;
+  nsCOMPtr<nsINode> node(do_QueryInterface(nativeObj));
+  NS_ENSURE_TRUE(node, NS_ERROR_UNEXPECTED);
   
-  if (content) {
   // Make sure that we get the owner document of the content node, in case
   // we're in document teardown.  If we are, it's important to *not* use
   // globalObj as the nodes parent since that would give the node the
   // principal of globalObj (i.e. the principal of the document that's being
   // loaded) and not the principal of the document that's being unloaded.
   // See http://bugzilla.mozilla.org/show_bug.cgi?id=227417
-    doc = content->GetOwnerDoc();
-  }
-
-  if (!doc) {
-    doc = do_QueryInterface(nativeObj);
+  nsIDocument* doc = node->GetOwnerDoc();
 
   if (!doc) {
     // No document reachable from nativeObj, use the global object
@@ -6440,27 +6435,25 @@ nsNodeSH::PreCreate(nsISupports *nativeObj, JSContext *cx, JSObject *globalObj,
 
     return NS_OK;
   }
-  }
 
   nsISupports *native_parent;
 
-  if (content) {
-    if (content->IsNodeOfType(nsINode::eXUL)) {
+  if (node->IsNodeOfType(nsINode::eELEMENT | nsINode::eXUL)) {
     // For XUL elements, use the parent, if any.
-      native_parent = content->GetParent();
+    native_parent = node->GetParent();
 
     if (!native_parent) {
       native_parent = doc;
     }
-    } else {
-      // For non-XUL elements, use the document as scope parent.
+  } else if (node->IsNodeOfType(nsINode::eCONTENT)) {
+    // For non-XUL content, use the document as scope parent.
     native_parent = doc;
 
     // But for HTML form controls, use the form as scope parent.
-      if (content->IsNodeOfType(nsINode::eELEMENT |
+    if (node->IsNodeOfType(nsINode::eELEMENT |
                            nsIContent::eHTML |
                            nsIContent::eHTML_FORM_CONTROL)) {
-        nsCOMPtr<nsIFormControl> form_control(do_QueryInterface(content));
+      nsCOMPtr<nsIFormControl> form_control(do_QueryInterface(node));
 
       if (form_control) {
         nsCOMPtr<nsIDOMHTMLFormElement> form;
@@ -6472,9 +6465,10 @@ nsNodeSH::PreCreate(nsISupports *nativeObj, JSContext *cx, JSObject *globalObj,
         }
       }
     }
-    }
   } else {
-    // We're called for a document object (since content is null),
+    NS_ASSERTION(node->IsNodeOfType(nsINode::eDOCUMENT),
+                 "Unexpected node");
+    // We're called for a document object (since node is not eCONTENT),
     // set the parent to be the document's global object, if there
     // is one