diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/basic/bug584499-2.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/basic/bug584499-2.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,12 @@
+function f(x) {
+    var s = "a";
+    var last = "";
+    for (var i = 0; i < 10; i++) {
+        last = s[x];
+    }
+    return last;
+}
+
+f(0);
+
+assertEq(f(1), undefined);