diff -r 000000000000 -r 6474c204b198 toolkit/mozapps/extensions/test/browser/browser_bug616841.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/mozapps/extensions/test/browser/browser_bug616841.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,21 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+function test_string_compare() {
+  ok("C".localeCompare("D") < 0, "C < D");
+  ok("D".localeCompare("C") > 0, "D > C");
+  ok("\u010C".localeCompare("D") < 0, "\u010C < D");
+  ok("D".localeCompare("\u010C") > 0, "D > \u010C");
+}
+
+function test() {
+  waitForExplicitFinish();
+
+  test_string_compare();
+
+  AddonManager.getAddonByID("foo", function(aAddon) {
+    test_string_compare();
+    finish();
+  });
+}