diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/basic/bug633409-1.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/basic/bug633409-1.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,13 @@
+// vim: set ts=8 sts=4 et sw=4 tw=99:
+x = { a: 1, b: 2, c: 3, d: 4, e: 5, f: 6 };
+
+for (i in x)
+    delete x.d;
+
+x = { a: 1, b: 2, c: 3, d: 4, e: 5, f: 6 };
+y = [];
+for (i in x)
+    y.push(i)
+    
+assertEq(y[3], "d");
+