diff -r 000000000000 -r 6474c204b198 js/xpconnect/tests/unit/test_want_components.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/xpconnect/tests/unit/test_want_components.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,8 @@
+function run_test() {
+  var cu = Components.utils;
+  var sb = cu.Sandbox(this, 
+	    {wantComponents: false});
+
+  var rv = cu.evalInSandbox("this.Components", sb);
+  do_check_eq(rv, undefined);
+}