Description:
------------
---
From manual page: http://www.php.net/function.extract
---

There is some non-documented behaviour when $array has a "this" key.  

If extract($array) is invoked within an object method then $this is not overwritten. This is totally understandable but 
- it should be documented 
- it should raise a notice

If extract() is invoked NOT within a method then $this is created. This looks logical but it contradicts the fact that $this cannot be created with a simple assignment. If this is an intended behaviour then it also should be documented, otherwise this is a bug. 

Test script:
---------------
<?php
	$array = array(
		"this" => "NOT THIS" 
	);

	error_reporting(E_ALL);
	class C {
		function t($arr) {
			extract($arr);
			print "this:";
			print_r($this);  // displays the object, not "NOT THIS", as one would expect
		}
	}
	
	$c = new C();
	$c->t($array);

	extract($array);  // it creates $this
	print $this;
	
	// $this = 0;   // this line would raise a Fatal Error