post_upgrade() {
    if (( $(vercmp $2 1.16.0-3) < 0 )); then
        post_install
    fi
}

post_install() {

    ## suid permission is not preserved during _install execution, fix it.
    chmod u+s /usr/lib/Xorg.wrap

    cat <<MSG
>>> Xorg-server has now the ability to run without root rights.
    To be able to use this features, install the package:
    xorg-server-rootless.

$(tput setaf 3)>>> WARNING: $(tput sgr0)
    The file /etc/X11/Xwrapper.config,
    need to be present on your system containing this line :

    needs_root_rights = yes

    See xorg.wrap man page (man xorg.wrap) for futher informations.
MSG
}