diff -r 000000000000 -r 6474c204b198 js/xpconnect/tests/unit/test_bug809674.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/xpconnect/tests/unit/test_bug809674.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,30 @@
+/* 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/. */
+
+const Cc = Components.classes;
+const Ci = Components.interfaces;
+
+function run_test() {
+
+  // Load the component manifest.
+  Components.manager.autoRegister(do_get_file('../components/js/xpctest.manifest'));
+
+  // Test for each component.
+  test_property_throws("@mozilla.org/js/xpc/test/js/Bug809674;1");
+}
+
+function test_property_throws(contractid) {
+
+  // Instantiate the object.
+  var o = Cc[contractid].createInstance(Ci["nsIXPCTestBug809674"]);
+
+  // Test the initial values.
+  try {
+    o.jsvalProperty;
+    do_check_true(false, "Should have thrown");
+  } catch (e) {
+    do_check_true(/implicit_jscontext/.test(e), "Should throw a helpful error");
+  }
+
+}