toBuffer throws an exception for PDUs that cannot have bodies

[xaka]

Hi there,

As per SMPP specification the submit_sm_resp command cannot have body if the status is not a zero. It's not respected by library and so you end up with:

../node_modules/smpp/lib/defs.js:70
                        value.copy(buffer, offset);
                              ^
TypeError: Cannot call method 'copy' of undefined
    at Object.types.cstring.write (../node_modules/smpp/lib/defs.js:70:10)
    at PDU.toBuffer (../node_modules/smpp/lib/pdu.js:136:20)
    at Session.send (../node_modules/smpp/lib/smpp.js:73:24)
    at Session.onPdu (../main.js:152:23)
    at Session.emit (events.js:95:17)
    at Session._extractPDUs (../node_modules/smpp/lib/smpp.js:52:8)
    at Socket.<anonymous> (../node_modules/smpp/lib/smpp.js:29:8)
    at Socket.emit (events.js:95:17)
    at Socket.<anonymous> (_stream_readable.js:748:14)
    at Socket.emit (events.js:92:17)

I'm not sure yet what would be the best solution, but as a workaround i had to add a check to toBuffer method and skip encoding.

We probably should add some kind of flag to commands that not allow the body when status is not a zero and add support for it to toBuffer method.

[farhadi]

Thanks for the report.
I just fixed it.