diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/basic/setprop.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/basic/setprop.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,10 @@
+function setprop()
+{
+  var obj = { a:-1 };
+  var obj2 = { b:-1, a:-1 };
+  for (var i = 0; i < 20; i++) {
+    obj2.b = obj.a = i;
+  }
+  return [obj.a, obj2.a, obj2.b].toString();
+}
+assertEq(setprop(), "19,-1,19");