Checking in Fabian's <hidday@geocities.com> patch for bug 6052. Make element.nodeValue return null in stead of empty string. sr=jst@netscape.com, no reviewer, trivial change

content/base/src/nsGenericElement.cpp

@@ -875,9 +875,7 @@ nsGenericElement::GetLocalName(nsAWritableString& aLocalName)
 NS_IMETHODIMP
 nsGenericElement::GetNodeValue(nsAWritableString& aNodeValue)
 {
-  // XXX: Null string
-
-  aNodeValue.Truncate();
+  SetDOMStringToNull(aNodeValue);
 
   return NS_OK;
 }