Cancel req issues

[disacod]

1. When processing Cancel, the first response is 487, then OK, which is incorrect.
2. When processing Cancel, the session hangs until the timeout with "WARN ACK missed." I think stateProceeding would be a better handler for fsm onCancel than inviteStateProcceeding.

[emiago]

Hi @disacod .

Ok I see your point. Probably even better error handling should be done as well, but even if we fix order, your client should threat them as seperate transcations. This can indicate also bad client.
OK is for CANCEL, 487 is for INVITE.

I have to look more further, as it would be also wrong to say CANCEL is processed successfully?

[disacod]

Hi @emiago.
I don't know about all clients, but opensips corrects the order. I understand it's a proxy, but anyway. And although the RFC doesn't explicitly state this order anywhere (except for the section on stateful proxy), I think it's good practice to first respond with OK to the request and then respond with 487 for INVITE.
In any case, I'm not insisting; even in this form, it works well. It's just perfectionism.

[emiago]

I think this majorly fixed now. In any case should be rebased @disacod and reopen