#!/bin/bash

set -e

usage () { echo >&2 'usage: cvs-adjustroot OLD NEW'; exit 1; }

case "$#.$1" in
4.--reinvoke)	reinvoke=true; shift	;;
*.-*)		usage			;;
2.*)		reinvoke=false		;;
1.*)		usage			;;
0.*)		usage			;;
*)		usage			;;
esac

# Copyright 2004 Ian Jackson <ian@chiark.greenend.org.uk>
#
# This script and its documentation (if any) are free software; you
# can redistribute it and/or modify them under the terms of the GNU
# General Public License as published by the Free Software Foundation;
# either version 3, or (at your option) any later version.
# 
# chiark-named-conf and its manpage are 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 along
# with this program; if not, consult the Free Software Foundation's
# website at www.fsf.org, or the GNU Project website at www.gnu.org.


old="$1"; shift
new="$1"; shift

if $reinvoke; then
	filename="$1";
	if cmp -- "$filename" <(printf "%s\n" "$new"); then exit 0; fi
	cmp -- "$filename" <(printf "%s\n" "$old")
	printf "%s\n" "$new" >"$filename".new
	mv -f -- "$filename".new "$filename"
	exit 0
fi

# GNU find provides + exec variants which set exit status and pass
# multiple arguments, or \; variants which pass one argument but do
# not set exit status.  So use a separate -exec false + to arrange for
# nonzero exit status when appropriate.

find	-path '*/CVS/Root'						\
  \(	-exec "$0" --reinvoke "$old" "$new" '{}' ';'			\
  -o	-exec false '{}' +						\
  \)