#!/bin/sh -e

# Copyright (C) 2002-2004  Masato Taruishi <taru@debian.org>
# Copyright (C) 2006       Junichi Uekawa <dancer@debian.org>
# Copyright (C) 2007       Jean Lepropre <jlepropre@gmail.com>
# Copyright (C) 2013       Francesco Poli <invernomuto@paranoici.org>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License with
# the Debian GNU/Linux distribution in file /usr/share/common-licenses/GPL-2;
# if not, write to the Free Software Foundation, Inc., 51 Franklin St,
# Fifth Floor, Boston, MA 02110-1301, USA.

prefclean()
{
    test -x /usr/share/apt-listbugs/aptcleanup || return 0
    test -x /usr/sbin/apt-listbugs || return 0
    test -f /etc/apt/preferences || return 0

    tmp=$(mktemp --tmpdir apt-listbugs_tmp_preferences.XXXXXX)

    /usr/share/apt-listbugs/aptcleanup > "$tmp" || return 0
    if ! diff -B "$tmp" /etc/apt/preferences > /dev/null
    then
        if test -f "/var/backups/apt-listbugs.preferences"
        then
            savelog -q /var/backups/apt-listbugs.preferences
        fi
        cp -aH /etc/apt/preferences /var/backups/apt-listbugs.preferences
        cp "$tmp" /etc/apt/preferences
    fi
    /bin/rm -f "$tmp"
}

prefclean

