Optionparser fails if there are no options

[baw-serafin]

We are developing a little demo but lobarocoap can't parse a response with no options. it fails of the following code in /src/coap_options.c

if (srcArr[0] == OPTION_PAYLOAD_MARKER) {
		INFO("- Options must not start with payload marker!\r\n");
		return COAP_PARSE_MESSAGE_FORMAT_ERROR;
}

Other clients like libcoap or coapthon or java libraries have no problem with the packets. And i can't see anything in the rfc either.

O the contrary there is stated options (if any):

0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |Ver| T |  TKL  |      Code     |          Message ID           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |   Token (if any, TKL bytes) ...
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |   Options (if any) ...
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |1 1 1 1 1 1 1 1|    Payload (if any) ...
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                         Figure 7: Message Format

Debug Output:

o<<<<<<<<<<<<<<<<<<<<<<
New Datagram received [7 Bytes], Interface #d

--------------->>> Sending Endpoint:
--------------->>> IPv4, 192.168.2.41:57095
--------------->>>

--------------->>> - Options must not start with payload marker!

--------------->>> CoAP-Parse Options Error

--------------->>> - (!) ERROR (!)
--------------->>> ParseResult:
--------------->>> COAP_PARSE_MESSAGE_FORMAT_ERROR

--------------->>> o<<<<<<<<<<<<<<<<<<<<<<

--------------->>>

--------------->>> Interactions: 1

--------------->>> -------------

--------------->>> - Role: CLIENT, State: WAITING_RESPONSE

--------------->>> RetransCnt: 0, SleepUntil 0, AckTimeout: 1516699926

Edit: No options not no headers

[niondir]

Thanks for reporting. I would agree, this should parse just fine.