1 files changed, 16 insertions, 0 deletions
diff --git a/js/xpconnect/tests/unit/test_bug780370.js b/js/xpconnect/tests/unit/test_bug780370.js
new file mode 100644
index 0000000000..e0da551201
--- /dev/null
+++ b/js/xpconnect/tests/unit/test_bug780370.js
@@ -0,0 +1,16 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* See https://bugzilla.mozilla.org/show_bug.cgi?id=780370 */
+
+// Use a COW to expose a function from a standard prototype, and make we deny
+// access to it.
+
+function run_test()
+{
+  var sb = Cu.Sandbox("http://www.example.com");
+  sb.obj = { foo: 42 };
+  Assert.equal(Cu.evalInSandbox('typeof obj.foo', sb), 'undefined', "COW works as expected");
+  Assert.equal(Cu.evalInSandbox('obj.hasOwnProperty', sb), undefined);
+}