can_diff () {
	return 1
}

merge_cmd () {
	if $base_present
	then
		touch "$BACKUP"
		"$merge_tool_path" \
			-base:"$BASE" -mine:"$LOCAL" \
			-theirs:"$REMOTE" -merged:"$MERGED"
		check_unchanged
	else
		echo "TortoiseMerge cannot be used without a base" 1>&2
		return 1
	fi
}