[OpenSIPS-Devel] [OpenSIPS/opensips] 1522bf: mid_registrar: Fix occasional undesired De-REGISTE...

[Liviu Chircu]

  Branch: refs/heads/3.3
  Home:   https://github.com/OpenSIPS/opensips
  Commit: 1522bfe5abd0f7ea5085f8bb281671fd550ba316
      https://github.com/OpenSIPS/opensips/commit/1522bfe5abd0f7ea5085f8bb281671fd550ba316
  Author: Liviu Chircu <liviu at opensips.org>
  Date:   2022-11-18 (Fri, 18 Nov 2022)

  Changed paths:
    M modules/mid_registrar/save.c

  Log Message:
  -----------
  mid_registrar: Fix occasional undesired De-REGISTER forwarding in mode 2

If the timings were aligned in a specific way, the mid-registrar (in AoR
throttling mode) would actually forward a De-REGISTER downstream even
though it had at least 1+ healthy remaining contacts after having
applied the De-REGISTER locally.  This would cause some degree of
service loss, as the remaining UAs were registered on the mid-reg, but
not on the backend.

Many thanks to Carlos Cruz Luengo (@cruzccl) and @ryan-netizen for an
accurate report, as well as helping come up with the fix!

Fixes #2615

(cherry picked from commit 502f1ab66257628f06bee7bf8ea4564ab5e8a160)