diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/basic/bug570385-2.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/basic/bug570385-2.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,9 @@
+var actual = '';
+
+var a = [0, 1];
+for (var i in a) {
+    appendToActual(i);
+    delete a[1];
+}
+
+assertEq(actual, "0,");