diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/jaeger/bug566022.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/jaeger/bug566022.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,8 @@
+function f() {
+  var a;
+  var o = { valueOf: function () { x = 99; return x; } };
+  var x = 2;
+  return [x, o + x, x]
+}
+assertEq(f().join(", "), "2, 101, 99");
+