diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/basic/testElemDec2.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/basic/testElemDec2.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,7 @@
+var obj = {s: ""};
+var name = "s";
+for (var i = 0; i <= 13; i++)
+    if (i > 8)
+        obj[name]--;  // first recording changes obj.s from string to number
+assertEq(obj.s, -5);
+