diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/auto-regress/bug721497.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/auto-regress/bug721497.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,13 @@
+// |jit-test| error:ReferenceError
+
+// Binary: cache/js-dbg-64-edf8075b0333-linux
+// Flags:
+//
+
+var g = newGlobal();
+var dbg = new Debugger(g);
+dbg.onDebuggerStatement = function (frame) {
+    assertEq(dumpStack(), true);
+};
+g.eval("function f(a, [b, c], {x: [y], z: w}, {q}) { debugger; }");
+g.eval("f(1, [2, 3], {x: [4], z: 5}, {q: 6});");