diff -r 000000000000 -r 6474c204b198 js/xpconnect/tests/unit/test_bug851895.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/xpconnect/tests/unit/test_bug851895.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,11 @@
+const Cu = Components.utils;
+
+function run_test() {
+  // Make sure Components.utils gets its |this| fixed up.
+  var isXrayWrapper = Components.utils.isXrayWrapper;
+  do_check_true(!isXrayWrapper({}), "Didn't throw");
+
+  // Even for classes without |this| fixup, make sure that we don't crash.
+  var isSuccessCode = Components.isSuccessCode;
+  try { isSuccessCode(Components.results.NS_OK); } catch (e) {};
+}