diff -r 000000000000 -r 6474c204b198 js/xpconnect/tests/unit/test_bug854558.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/xpconnect/tests/unit/test_bug854558.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,11 @@
+const Cu = Components.utils;
+function run_test() {
+
+  var chromeSB = new Cu.Sandbox(this);
+  var contentSB = new Cu.Sandbox('http://www.example.com');
+  Cu.evalInSandbox('this.foo = {a: 2}', chromeSB);
+  contentSB.foo = chromeSB.foo;
+  do_check_eq(Cu.evalInSandbox('foo.a', contentSB), undefined, "Default deny with no __exposedProps__");
+  Cu.evalInSandbox('this.foo.__exposedProps__ = {a: "r"}', chromeSB);
+  do_check_eq(Cu.evalInSandbox('foo.a', contentSB), 2, "works with __exposedProps__");
+}