diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/arguments/testDelArg1.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/arguments/testDelArg1.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,13 @@
+function f(x,y,z) {
+  z = 9;
+  delete arguments[2];
+  assertEq(arguments[2], undefined);
+  o = arguments;
+  assertEq(o[2], undefined);
+  assertEq(o[2] == undefined, true);
+}
+
+for (var i = 0; i < 10; ++i) {
+    print(i);
+    f(1,2,3)
+}