Break cycle-through-XPCOM by adding an assignment to null when done with |iterator|. b=285065 r+sr=bryner

toolkit/content/widgets/radio.xml

@@ -221,6 +221,11 @@
           while (iterator.nextNode())
             radioChildren.push(iterator.currentNode);
 
+          // assign null to break circular reference between _filterRadioGroup
+          // and iterator (via this scope)
+          // XXX The function really should be global instead of local.
+          iterator = null;
+
           return this.mRadioChildren = radioChildren;
         ]]>
         </body>

xpfe/global/resources/content/bindings/radio.xml

@@ -220,6 +220,12 @@
           var iterator = this.ownerDocument.createTreeWalker(this, NodeFilter.SHOW_ELEMENT, _filterRadioGroup, true);
           while (iterator.nextNode())
             radioChildren.push(iterator.currentNode);
+
+          // assign null to break circular reference between _filterRadioGroup
+          // and iterator (via this scope)
+          // XXX The function really should be global instead of local.
+          iterator = null;
+
           return this.mRadioChildren = radioChildren;
         ]]>
         </body>