michael@0: function f() {
michael@0:   var a;
michael@0:   var o = { valueOf: function () { x = 99; return x; } };
michael@0:   var x = 2;
michael@0:   return [x, o + x, x]
michael@0: }
michael@0: assertEq(f().join(", "), "2, 101, 99");
michael@0: