ObjFW  Check-in [431696dee5]

		[data addItems: &tmp16 count: sizeof(tmp16)];
		[data addItems: extension.items count: extension.count];
	}

	/* Zero-length extension to terminate */
	[data increaseCountBy: 2];

	/*
	 * Some implementations only check the first byte to see if the end of
	 * the archive has been reached, which is 0 for every multiple of 256.
	 * Add one byte of padding to avoid this.
	 */
	if ((data.count & 0xFF) == 0)
		[data increaseCountBy: 1];

	headerSize = data.count;

	if (headerSize > UINT16_MAX)
		@throw [OFOutOfRangeException exception];

	/* Now fill in the size and CRC16 for the entire header */
	tmp16 = OFToLittleEndian16(headerSize);