diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/for-of/arrays-slow-1.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/for-of/arrays-slow-1.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,8 @@
+// for-of works on slow arrays.
+
+var a = ['a', 'b', 'c'];
+a.slow = true;
+var log = '';
+for (var x of a)
+    log += x;
+assertEq(log, 'abc');