diff -r 000000000000 -r 6474c204b198 js/xpconnect/tests/unit/test_getObjectPrincipal.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/xpconnect/tests/unit/test_getObjectPrincipal.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,11 @@
+const Cc = Components.classes;
+const Ci = Components.interfaces;
+const Cu = Components.utils;
+
+function run_test() {
+  var secMan = Cc["@mozilla.org/scriptsecuritymanager;1"].getService(Ci.nsIScriptSecurityManager);
+  do_check_true(secMan.isSystemPrincipal(Cu.getObjectPrincipal({})));
+  var sb = new Cu.Sandbox('http://www.example.com');
+  Cu.evalInSandbox('var obj = { foo: 42 };', sb);
+  do_check_eq(Cu.getObjectPrincipal(sb.obj).origin, 'http://www.example.com');
+}