diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/basic/setArgumentsLength.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/basic/setArgumentsLength.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,14 @@
+var count = 0;
+
+function f() {
+  arguments.length--;
+  for (var i = 0; i < arguments.length; ++i) {
+    ++count;
+  }
+}
+
+f(1, 2);
+f(1, 2);
+f(2, 2);
+
+assertEq(count, 3);