#!/bin/sh

set -e 

# DEP17 M18: Duplicate diversion in aliased location /sbin.

case "$1" in
	install)
		# canonical path; the one we are using going forward.
		dpkg-divert --package isc-dhcp-client-ddns --add --rename \
			--divert /usr/sbin/dhclient-noddns /usr/sbin/dhclient
		# aliased path, for upgrades. postinst will --remove it.
		dpkg-divert --package isc-dhcp-client-ddns --add --rename \
			--divert /sbin/dhclient-noddns.usr-is-merged /sbin/dhclient

		;;

	upgrade)
		TRUENAME=$(dpkg-divert --truename /usr/sbin/dhclient)
		if test "$TRUENAME" = /usr/sbin/dhclient.usr-is-merged; then
			# isc-dhcp-client.preinst duplicated the diversion for us.
			# Remove duplicated diversion.
			dpkg-divert --package isc-dhcp-client-ddns --remove --no-rename \
				--divert /usr/sbin/dhclient.usr-is-merged /usr/sbin/dhclient
			dpkg-divert --package isc-dhcp-client-ddns --add --no-rename \
				--divert /usr/sbin/dhclient-noddns /usr/sbin/dhclient
			dpkg-divert --package isc-dhcp-client-ddns --remove --no-rename \
				/sbin/dhclient
			dpkg-divert --package isc-dhcp-client-ddns --add --no-rename \
				--divert /sbin/dhclient-noddns.usr-is-merged /sbin/dhclient
			mv "$TRUENAME" /usr/sbin/dhclient-noddns
		elif test "$TRUENAME" != /usr/sbin/dhclient-noddns; then
			dpkg-divert --package isc-dhcp-client-ddns --add --no-rename \
				--divert /usr/sbin/dhclient-noddns /usr/sbin/dhclient
			TRUENAME=$(dpkg-divert --truename /sbin/dhclient)
			dpkg-divert --package isc-dhcp-client-ddns --remove --no-rename \
				/sbin/dhclient
			dpkg-divert --package isc-dhcp-client-ddns --add --no-rename \
				--divert /sbin/dhclient-noddns.usr-is-merged /sbin/dhclient
			if test -e "$TRUENAME"; then
				mv "$TRUENAME" "/sbin/dhclient-noddns.usr-is-merged"
			fi
		fi

		;;
esac