Description:
------------
In the case below where the callback function is private, its static local 
variable is lost during call of inherited class,

t if the callback function is private as below, it still gets called, but the 
local static variable is null instead of initialized like in PHP 5.2, where it 
works.

Also if you make the callback function "protected" instead of "private", the 
result is correct, as expected.

This is reproducible at least on PHP 5.3.8.

Test script:
---------------
class ok {
	public function t() {
		$this->replacer( '*' );
		return preg_replace_callback( '/(t)/', array( $this, 'replacer'), 'this is a simple test' );
	}
	private function replacer( $input ) {
		static $cache					=	'-';
		if ( ! is_array( $input ) ) {
			$cache						=	$input;
		} else {
			return $cache . $input[1] . $cache;
		}
	}
}
class buggyphp extends ok {}

class buggyphptoo extends ok {
	public function t() {
		return parent::t();
	}
}

$buggy = new buggyphp();
echo 'Result buggyphp: ' . $buggy->t();
echo "\n";
$buggy = new buggyphptoo();
echo 'Result buggyphptoo: ' . $buggy->t();
echo "\n";
$a = new ok();
echo 'Result ok: ' . $a->t();
exit();


Expected result:
----------------
Result buggyphp: *t*his is a simple *t*es*t*
Result buggyphptoo: *t*his is a simple *t*es*t*
Result ok: *t*his is a simple *t*es*t*

Actual result:
--------------
Result buggyphp: -t-his is a simple -t-es-t-
Result buggyphptoo: -t-his is a simple -t-es-t-
Result ok: *t*his is a simple *t*es*t*