diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/basic/testBug458838.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/basic/testBug458838.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,14 @@
+var escape;
+function testBug458838() {
+    var a = 1;
+    function g() {
+        var b = 0
+            for (var i = 0; i < 10; ++i) {
+                b += a;
+            }
+        return b;
+    }
+
+    return g();
+}
+assertEq(testBug458838(), 10);