diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/auto-regress/bug722023.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/auto-regress/bug722023.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,12 @@
+// Binary: cache/js-dbg-64-8a59519e137e-linux
+// Flags: -m -n -a
+//
+
+var obj = new Object();
+var index = [ (null ), 1073741824, 1073741825 ];
+for (var j in index) {
+  testProperty(index[j]);
+}
+function testProperty(i) {
+  actual = obj[String(i)];
+}