adsense destructive function!

Google AdSense is a free and cool service and is widely used inside many sites.

It allows site managers to get paid while they show their content ... it's great and thank You Google for this service.

However adsense uses a function that's probably the most obtrusive one You can use or find while You write JavaScript.
This function is exactely this one:

function $(b){
 for(var a in K){
  b[a]=null
 }
}

Using them with own objects is absolutely not a problem but what kind of object do You think that b is? The Window one!

It's absolutely a non-sense for a service that uses JavaScript inside a closure to respect other libraries and to be free to use every name it needs to be executed!

Why this function is an obtrusive monster?

We always use third party libraries or We write JavaScript directly but in both cases We (others) should implement a generic Object.prototype inside our code ... just think, for example, to toJSONString prototype, OK ?

Now suppose that You write your own function, called toJSONString to manage everything else, objects too.

function toJSONString(){
 // doStuff
};

Just add adsense in Your page and everything will not work ... seems interesting?

The right thing is that Object.prototype is always a problem if You don't use method hasOwnProperty inside a generic for(var key in obj) loop.
If You forgot them You should parse, manage, modify, properties that aren't part of your code (however these shoulkd be a part of your code too) and that's exactely what adsense does at the end of its execution.

The reason seems to be simple, adsense script would remove every global variables You write everytime You need them to allow a single page to contain different versions of adsense without any sort of problem with precedent settings.

At the same time every method or parameter assigned to Object.prototype will be "globally deleted" (becoming a null value) so if DjProto called one prototype, for example, escape You'll never be able to use escape as a native function.
At the same time google adsense code itself should fail too because if I write 2 prototypes like these:

Object.prototype.escape = Object.prototype.encodeURIComponent = function(){
        return escape(this.toString());
};

and I add one adsense in my page, next one will not be able to encode any kind of string that should be sent to Google service.

Cool?

A really simple and crossbrowser solution

Since Object.prototype.hasOwnProperty is available only in IE6 or greater (I can't remembre if IE 5.5 has it) Google shouldn't implement this check but it should implement another one even more simple but efficient for this purpose.

function $(b){
 for(var a in K){
  if(Object.prototype[a]!=K[a])
   b[a]=null
 }
}

In this way every JavaScript compatible browser will remove or will assign to null Google adsense global scoped K object properties only (that are, again, objects of this type google_rl_mode:{url_param:"rl_mode",gfp:0}) without enviroment destruction possibility :-)

Another trick should be this one:

function $(b){
 for(var a in K){
  if(/^google/i.test(a))
   b[a]=null
 }
}

Finally, this post should be helpful to understand better for in loops and problems adding Object.prototype parameters or methods ... and at the same time is another reason to pray that ES4 will be available as soon as Mozilla developers can - it simply let You define which property should be enumerable and which not!