#!/bin/sh
set -e

# Relocate a conffile from one location to another; it is removed iff
# unmodified, and moved iff modified.
# The undo path is postrm abort-install|abort-upgrade.
# $1 is the old pathname of the conffile,
# $2 is the new pathname of the conffile.
mv_conffile ()
{
	[ ! -f "$1" ] && return
	if [ -e "$2" ] ; then
		echo "Not moving conffile $1 to $2; new file exists"
		return
	fi

	orgmd5=`dpkg-query -W -f='${Conffiles}' dpkg | cut -d' ' -f3`
	curmd5=`md5sum $1 |sed -e 's/ .*//'`
	if [ "$orgmd5" = "$curmd5" ]; then
		# conffile unmodified; prepare to remove it, allowing
		# dpkg to install a new copy to the new location
		# before "configuration"
		echo "Preparing to remove unmodified conffile:"
		echo -n " "
		mv -fv $1 $1.moved_by_preinst
	else
		# conffile modified by admin; relocate it, causing
		# dpkg to prompt, as intended
		echo "Relocating modified conffile to new location:"
		echo -n " "
		mv -fv $1 $2
	fi >&2
}

p1=/etc
p2=/etc/john
case $1 in
install|upgrade)
	[ -d $p2 ] || mkdir $p2
	if dpkg --compare-versions "$2" le-nl 1.6-27; then
		mv_conffile $p1/john.ini $p2/john.conf
		mv_conffile $p1/john-mail.conf $p2/john-mail.conf
		mv_conffile $p1/john-mail.msg $p2/john-mail.msg

	# No need to remove the obsolete conffile
	# /etc/cron.daily/john, since old prerm does so
	# unconditionally (and there is nothing we can do to stop it)
	fi
	;;

abort-upgrade)
	# This case needs no actions here
	;;

*)
	echo "$0: undocumented call: $@"
	exit 1
	;;
esac