This script (stupid) makes php crash. I know is a fail of the developer but still a crash.
<?php
class foo {
    var $a = "orig value";
    
    function register() {
        $bar =& $this;
        $bar->updateA('new value');
    }
    
    function updateA($val) {
        $this->register();
        $this->a = $val;
    }
}

$foo = new Foo;
$foo->updateA("new value");

?>