diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/debug/Environment-gc-02.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/debug/Environment-gc-02.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,28 @@
+// A closure's .environment keeps the lexical environment alive even if the closure is destroyed.
+
+var N = 4;
+var g = newGlobal();
+g.eval("function add(a) { return function (b) { return eval('a + b'); }; }");
+var dbg = new Debugger;
+var gw = dbg.addDebuggee(g);
+var aw = gw.getOwnPropertyDescriptor("add").value;
+
+// Create N closures and collect environments.
+var arr = [];
+for (var i = 0; i < N; i++)
+    arr[i] = aw.call(null, i).return.environment;
+
+// Test that they work now.
+function check() {
+    for (var i = 0; i < N; i++) {
+        assertEq(arr[i].find("b"), null);
+        assertEq(arr[i].find("a"), arr[i]);
+    }
+}
+check();
+
+// Test that they work after gc.
+gc();
+gc({});
+g.gc(g);
+check();