[OpenSIPS-Devel] [OpenSIPS/opensips] 1dfeb2: Fix CANCELLing of transactions not forwarded.

[Bogdan-Andrei Iancu]

  Branch: refs/heads/2.1
  Home:   https://github.com/OpenSIPS/opensips
  Commit: 1dfeb255bb2b798f02a3b5d2ac1fe2536a203122
      https://github.com/OpenSIPS/opensips/commit/1dfeb255bb2b798f02a3b5d2ac1fe2536a203122
  Author: Bogdan-Andrei Iancu <bogdan at opensips.org>
  Date:   2016-10-13 (Thu, 13 Oct 2016)

  Changed paths:
    M modules/tm/t_fwd.c

  Log Message:
  -----------
  Fix CANCELLing of transactions not forwarded.

Due async operations, a transaction may be created and it may exist for a long time before any branch is created for it (via a t_relay). The current fix takes care and does proper handling on incoming CANCELs matching the transaction while it has no branch (no t_relay() on it).
Old behavior - the INVITE transaction was never getting a final reply
New brhavior - the INVITE transaction gets an internally generated 487.

(cherry picked from commit fb0d90ec75601304eed98168bb988ebdbf10c260)