Revision 1895555

Merge r1894171 from trunk:

*) core: Be safe with ap_lingering_close() called with a socket NULL-ed.

PR 65627. 

mod_itk seems to:
  ap_set_core_module_config(c->conn_config, NULL)
before calling ap_lingering_close(), causing a crash after r1891721.
Until we have an API to no-op ap_lingering_close(), let's be safe.

* server/connection.c(ap_start_lingering_close):
  The socket should not be NULL here, add an assertion.

* server/connection.c(ap_lingering_close):
  Set c->aborted if the socket is NULL, and give up.


Submitted by: acmondor <bz.apache.org acmondor.ca>, ylavic
Reviewed by: ylavic, icing, rpluem
Github: closes #277