#!/bin/sh

set -e
err() {
	echo $@ >&2
	exit 1
}

clean() {
	rm -rf ${dir}
	exit 1
}

ask() {
	question=${1}

	answer=x
	while [ "${answer}" != "y" -a "${answer}" != "n" ] ; do
		read -p "${question} [yn] " answer
	done

	[ "${answer}" = "y" ] && return 0
	return 1
}

[ $# -ne 2 ] && err "Takes 2 arguments: <branch> <revnumber>"
branch=$1
rev=$2
case $rev in
''|*[!0-9]*) err "revision should be a number" ;;
esac

dir=$(mktemp -d /tmp/merge.XXX)
cd $dir
svn co --depth=empty svn+ssh://svn.FreeBSD.org/ports/branches/${branch}
filelist=""
for f in $(svn diff --summarize -c $rev svn://svn.FreeBSD.org/ports/head); do
	case ${f} in
	*/*) ;;
	*)continue;;
	esac
	f=${f#*/ports/head/}
	f=${f%/*}
	filelist="$filelist\n$f"
done
filelist=$(echo -e $filelist | sort -u)
echo "MFH: r$rev" > commit.txt
svn log -r$rev svn://svn.freebsd.org/ports/head | sed '1,2d;$d' >> commit.txt
for f in ${filelist}; do
	svn up --parents ${branch}/${f}
done
svn merge -c r${rev} ^/head/ ${branch}
svn up --quiet ${branch}
svn diff ${branch}
ask "Do you want to commit?" || clean
${EDITOR:-vi} commit.txt
svn ci -F commit.txt ${branch}
rm -rf $dir