unwatchOne gets NRE if property is added after watch is called

[Sempiternity87]

If you start watching an object, then add an object as a new property to it, the unwatchOne gets an error when trying to access properties from watchers of this new object. Since it didn't exist when first watched, it never got the watchers property, and causes a Null Reference Exception.

var obj = {};
var watchFunc = function(prop, action, difference, oldValue)
  {
  if (!(prop == 'modified' || obj.modified)) obj.modfied = true;
  };
obj.prop1 = 'Hello';
watch(obj, watchFunc, 2);
obj.items = [{'prop2':'Hello'},{'prop3':'World'}];
unwatch(obj, watchFunc);
//Cannot read property 'prop2' of undefined (looking for obj.watchers[prop]
//where watchers doesn't exist).

suggest changing
if (obj.watchers[prop]) {
to
if (obj.watchers && obj.watchers[prop]) {

[Raymond]

Hi,

Thanks for the fix.