Bug 774914 - Ensure newNode is orphan before replacing a node in JSDOMParser (r=mfinkle)

mobile/android/chrome/content/JSDOMParser.js

@@ -323,6 +323,9 @@
       if (childIndex == -1) {
         throw "replaceChild: node not found";
       } else {
+        if (newNode.parentNode)
+          newNode.parentNode.removeChild(newNode);
+
         childNodes[childIndex] = newNode;
         newNode.parentNode = this;
         oldNode.parentNode = null;