#!/hint/sh
# Set XDG_RUNTIME_DIR if we can
if [ -z "$XDG_RUNTIME_DIR" ] && type flock &>/dev/null; then
	_diy_xdg_runtime_login() {
		export XDG_RUNTIME_DIR="$XDG_CACHE_HOME/xdg-runtime-dir/$HOSTNAME.dir"
		if ! [ /dev/fd/7 -ef "$XDG_CACHE_HOME/xdg-runtime-dir/$HOSTNAME.lock" ]; then
			mkdir -p -- "$XDG_CACHE_HOME/xdg-runtime-dir"
			exec 7>"$XDG_CACHE_HOME/xdg-runtime-dir/$HOSTNAME.lock"
			if flock -xn 7; then
				if [ ! -d "$XDG_RUNTIME_DIR" ]; then
					local tmp="$(mktemp -d --tmpdir -- "${USER}@${HOSTNAME}-runtime.XXXXXXXXXX")"
					ln -sfT -- "$tmp" "$XDG_RUNTIME_DIR"
				fi
				# Unfortunately this doesn't survive across exec(1).
				trap _diy_xdg_runtime_logout EXIT
				flock -sn 7
			fi
		fi
	}
	_diy_xdg_runtime_logout() {
		if flock -xn 7; then
			rm -rf -- "$(readlink "$XDG_RUNTIME_DIR")"
			rm -f -- "$XDG_RUNTIME_DIR"
		fi
	}
	_diy_xdg_runtime_login
fi