#!/bin/sh
set -e

fail () { echo >&2 "$0: $*"; exit 127; }

case "$1" in
--v1) how=tip ;;
--v1-base) how=base ;;
--v1-dep) how=dep ;;
*) fail "bad usage" ;;
esac

whichfile=$1
ancestor=$2
current=$3
other=$4
markersize=$5

case $on.$whichfile in
dep.msg|dep.deps|dep.flags)
	touch "$current"
	exit 0
	;;
base.msg|base.deps)
	echo '# not applicable' >"$current"
	exit 0
	;;
base.flags)
	exec topbloke-merge-lists -UDeleted "$current" "$ancestor" "$other"
	;;
tip.msg)
	exec git-merge-file --marker-size=$markersize \
		"$current" "$ancestor" "$other"
	;;
tip.deps|tip.flags|*.included|*.pflags)
	exec topbloke-merge-lists "$current" "$ancestor" "$other"
	;;
*)
	fail "huh $on $whichfile ?"
	;;
esac