Chain-in a new PHP error_handler not destroying the old one.

chain_error_handlers.php

<?php
  
	set_error_handler(function(){ echo "INTERNAL\n"; });
	
	
	function chain_error_handler($new_handler){
		$old_handler = set_error_handler(function() use (&$old_handler,$new_handler){
			call_user_func_array($new_handler,func_get_args());
			call_user_func_array($old_handler,func_get_args());
		});
	}
	
	
	chain_error_handler(function(){ echo ":D\n"; });
	

	
	$a = 1/0;