diff -r 000000000000 -r 6474c204b198 browser/base/content/test/general/browser_bug609700.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/base/content/test/general/browser_bug609700.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,20 @@
+function test() {
+  waitForExplicitFinish();
+
+  Services.ww.registerNotification(function (aSubject, aTopic, aData) {
+    if (aTopic == "domwindowopened") {
+      Services.ww.unregisterNotification(arguments.callee);
+
+      ok(true, "duplicateTabIn opened a new window");
+
+      whenDelayedStartupFinished(aSubject, function () {
+        executeSoon(function () {
+          aSubject.close();
+          finish();
+        });
+      }, false);
+    }
+  });
+
+  duplicateTabIn(gBrowser.selectedTab, "window");
+}