Description:
------------
calling to ssh2_shell() causes a segment fault.

Test script:
---------------
#!/usr/bin/php
<?php

if (!$ssh = ssh2_connect('host', 22)) {
	die('Error trying connect to ssh host');
};

if (!ssh2_auth_password($ssh, 'username', 'thepass')) {
	die('Authentication by userpass failed');
}

if (!$shell = ssh2_shell($ssh, 'vanilla',array(),80, 25,SSH2_TERM_UNIT_CHARS)) {
	die('Interactive shell failed');
}


Expected result:
----------------
with previous versions I got an interactive stream from ssh2_shell()

Actual result:
--------------
segment fault.