In sub_client.c, call mosquitto_destroy() in cleanup label.

[basavesh]

Fixes #1513
Signed-off-by: Basavesh Shivakumar [email protected]

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---

[basavesh]

@ralight,
I'm not 100% sure if it is OK to call mosquitto_destroy even when there is an error from SIGALRM sigaction. If that is not OK, I can call mosquitto_destroy during the error return status check of client_connect().

alternative fix:
rc = client_connect(mosq, &cfg); if(rc){ mosquitto_destroy(mosq); goto cleanup; }

After fix:
Invoking mosquitto_sub when the server is not up / available.

valgrind --tool=memcheck --leak-check=yes --show-reachable=yes --num-callers=20 --track-fds=yes ./mosquitto_sub -v -t test
==28378== Memcheck, a memory error detector
==28378== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
==28378== Using Valgrind-3.13.0 and LibVEX; rerun with -h for copyright info
==28378== Command: ./mosquitto_sub -v -t test
==28378==
Error: Connection refused
==28378==
==28378== FILE DESCRIPTORS: 3 open at exit.
==28378== Open file descriptor 2: /dev/pts/5
==28378==
==28378==
==28378== Open file descriptor 1: /dev/pts/5
==28378==
==28378==
==28378== Open file descriptor 0: /dev/pts/5
==28378==
==28378==
==28378==
==28378== HEAP SUMMARY:
==28378== in use at exit: 0 bytes in 0 blocks
==28378== total heap usage: 3,780 allocs, 3,780 frees, 176,188 bytes allocated
==28378==
==28378== All heap blocks were freed -- no leaks are possible
==28378==
==28378== For counts of detected and suppressed errors, rerun with: -v
==28378== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)

[basavesh]

I amended the commit to handling SIGTERM and SIGINT signals to gracefully shutdown.
Otherwise, Valgrind will complain when we terminate the mosquitto_sub via CTRL+C

[ralight]

I don't think this was causing many problems as it was, but it's nice to have things cleaned up. Thanks very much.