What this patch does is looks for a '.' in the users home directory,
then calls chroot(2) to whatever directory was before the . and
continues with the normal ssh functionality. E.G. If your home directory
was /chroot/./home/bob, you'd be chrooted to /chroot and
/chroot/home/bob would actually appear as /home/bob to you. Check the
documentation for further explanations at
http://chrootssh.sourceforge.net/index.php