Description:
------------
pcnt_exec() does not check path validity. It should not allow NULL char, just like other file related functions.

I think exec() should not allow NULL char, too.

I'll prepare the patch.
Any comments?


Test script:
---------------
<?php
$path = "/bin/rm\0/usr/local/bin/my_special_program";
$opts = array('my_important_file');
if (!mb_ereg('my_special_program\z', $path)) {
   die('Go away');
}

pcntl_exec($path, $opts);