diff -r 000000000000 -r 6474c204b198 toolkit/devtools/server/tests/unit/test_objectgrips-07.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/devtools/server/tests/unit/test_objectgrips-07.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,65 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+/**
+ * This test checks that objects which are not extensible report themselves as
+ * such.
+ */
+
+var gDebuggee;
+var gClient;
+var gThreadClient;
+
+function run_test()
+{
+  initTestDebuggerServer();
+  gDebuggee = addTestGlobal("test-grips");
+  gDebuggee.eval(function stopMe(arg1, arg2, arg3, arg4) {
+    debugger;
+  }.toString());
+
+  gClient = new DebuggerClient(DebuggerServer.connectPipe());
+  gClient.connect(function() {
+    attachTestTabAndResume(gClient, "test-grips", function(aResponse, aTabClient, aThreadClient) {
+      gThreadClient = aThreadClient;
+      test_object_grip();
+    });
+  });
+  do_test_pending();
+}
+
+function test_object_grip()
+{
+  gThreadClient.addOneTimeListener("paused", function(aEvent, aPacket) {
+    let [f, s, ne, e] = aPacket.frame.arguments;
+    let [fClient, sClient, neClient, eClient] = aPacket.frame.arguments.map(
+      a => gThreadClient.pauseGrip(a));
+
+    do_check_false(f.extensible);
+    do_check_false(fClient.isExtensible);
+
+    do_check_false(s.extensible);
+    do_check_false(sClient.isExtensible);
+
+    do_check_false(ne.extensible);
+    do_check_false(neClient.isExtensible);
+
+    do_check_true(e.extensible);
+    do_check_true(eClient.isExtensible);
+
+    gThreadClient.resume(_ => {
+      finishClient(gClient);
+    });
+  });
+
+  gDebuggee.eval("(" + function () {
+    let f = {};
+    Object.freeze(f);
+    let s = {};
+    Object.seal(s);
+    let ne = {};
+    Object.preventExtensions(ne);
+    stopMe(f, s, ne, {});
+  } + "())");
+}
+