michael@0: function f() {
michael@0:     var n;
michael@0:     var k;
michael@0:     for (var i = 0; i < 18; ++i) {
michael@0: 	n = undefined;
michael@0: 	k = n++;
michael@0: 	if (k) { }
michael@0:     }
michael@0:     return [k, n];
michael@0: }
michael@0: 
michael@0: var [a, b] = f();
michael@0: 
michael@0: assertEq(isNaN(a), true);
michael@0: assertEq(isNaN(b), true);