diff -r 000000000000 -r 6474c204b198 testing/mochitest/tests/browser/browser_popupNode.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/testing/mochitest/tests/browser/browser_popupNode.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,4 @@
+function test() {
+  document.popupNode = document;
+  isnot(document.popupNode, null, "document.popupNode has been correctly set");
+}