/**
 * js increment operators (ob.prop += ob2.prop) do not work, after assigment like this ob = ob2
 * 
 * Affected versions:	r2.1.0-1580-g0c1a6bd (v8)
 * 				v8 engine: Version 3.9.23
 * 
 * 				2.0.3-1 (spider monkey)
 */

db.eval(function() {
	var ob2 = null;
	var ob1 = {foo: 1};
	ob2 = ob1;
	// if uncomment, than works
// 	ob2 = {};
// 	for (i in ob1) {
// 		ob2[i] = ob1[i];
// 	}

	ob2.foo += ob1.foo;
	assert(2 == ob2.foo, "increment #2, must be: 2");
	assert(ob2.foo == (1 + ob1.foo), "increment #1, must be: " + ob2.foo);
	return ob2.foo;
});