Squashed commit of the following:

commit 1f58495
Author: Jared Jurkiewicz <jared.jurkiewicz@gmail.com>
Date:   Thu Jun 26 11:03:00 2014 -0400

    Fix issue with parentNode as null, fixes #18130

Author: Some Contributor

request/iframe.js

@@ -179,7 +179,7 @@ define([
 					var parentNode = formNode;
 					do{
 						parentNode = parentNode.parentNode;
-					}while(parentNode !== win.doc.documentElement);
+					}while(parentNode && parentNode !== win.doc.documentElement);
 
 					// Append the form node or some browsers won't work
 					if(!parentNode){