#!/bin/sh

set -e

# summary of how this script can be called:
#
#   * <new-preinst> `install'
#   * <new-preinst> `install' <old-version> <new-version>
#   * <new-preinst> `upgrade' <old-version> <new-version>
#   * <old-preinst> `abort-upgrade' <new-version>
#
# for details, see https://www.debian.org/doc/debian-policy/ or
# the debian-policy package

create_protective_diversion() {
    local usrfile="$1"
    local firstver="$2"

    if [ "$3" != "--" ]; then
        echo "create_protective_diversion called with the wrong number of arguments" >&2
        return 1
    fi
    for _ in $(seq 1 3); do
        shift
    done

    # If we're upgrading from a new enough version of the package, it means
    # that usr-merge has already happened and we don't need to mess with
    # diversions at all
    if [ -n "$2" ] && dpkg --compare-versions -- "$2" gt "$firstver"; then
        return 0
    fi

    dpkg-divert \
        --no-rename \
        --divert "$usrfile.usr-is-merged" \
        --add "$usrfile"
}

DAEMON_COMMON_UNITS="
    libvirt-guests.service
    virt-guest-shutdown.target
"

case "$1" in
    install|upgrade)
        for unit in $DAEMON_COMMON_UNITS; do
            create_protective_diversion \
                "/lib/systemd/system/$unit" \
                "10.6.0-3~" \
                -- \
                "$@"
        done
    ;;

    abort-upgrade)
    ;;

    *)
        echo "preinst called with unknown argument \`$1'" >&2
        exit 1
    ;;
esac

# Automatically added by dh_installinit/13.24.2
if [ "$1" = "install" ] && [ -n "$2" ] && [ -e "/etc/init.d/libvirt-guests" ] ; then
	chmod +x "/etc/init.d/libvirt-guests" >/dev/null || true
fi
# End automatically added section


exit 0