if client_shared.c:client_connect fails, sub_client.c:main() doesn't call mosquitto_destroy

[basavesh]

Repro: Start a mosquitto_sub without starting a broker.

valgrind --tool=memcheck --leak-check=yes --show-reachable=yes --num-callers=20 --track-fds=yes ./mosquitto_sub -v -t test
==23425== Memcheck, a memory error detector
==23425== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
==23425== Using Valgrind-3.13.0 and LibVEX; rerun with -h for copyright info
==23425== Command: ./mosquitto_sub -v -t test
==23425==
Error: Connection refused
==23425==
==23425== FILE DESCRIPTORS: 5 open at exit.
==23425== Open AF_UNIX socket 6:
==23425== at 0x5176EFA: socketpair (syscall-template.S:78)
==23425== by 0x4E4757B: ??? (in /usr/lib/x86_64-linux-gnu/libmosquitto.so.1)
==23425== by 0x4E42945: ??? (in /usr/lib/x86_64-linux-gnu/libmosquitto.so.1)
==23425== by 0x4E42CEA: mosquitto_connect_bind_v5 (in /usr/lib/x86_64-linux-gnu/libmosquitto.so.1)
==23425== by 0x10ECC6: client_connect (client_shared.c:1201)
==23425== by 0x10A3DF: main (sub_client.c:332)
==23425==
==23425== Open AF_UNIX socket 5:
==23425== at 0x5176EFA: socketpair (syscall-template.S:78)
==23425== by 0x4E4757B: ??? (in /usr/lib/x86_64-linux-gnu/libmosquitto.so.1)
==23425== by 0x4E42945: ??? (in /usr/lib/x86_64-linux-gnu/libmosquitto.so.1)
==23425== by 0x4E42CEA: mosquitto_connect_bind_v5 (in /usr/lib/x86_64-linux-gnu/libmosquitto.so.1)
==23425== by 0x10ECC6: client_connect (client_shared.c:1201)
==23425== by 0x10A3DF: main (sub_client.c:332)
==23425==
==23425== Open file descriptor 2: /dev/pts/1
==23425==
==23425==
==23425== Open file descriptor 1: /dev/pts/1
==23425==
==23425==
==23425== Open file descriptor 0: /dev/pts/1
==23425==
==23425==
==23425==
==23425== HEAP SUMMARY:
==23425== in use at exit: 1,002 bytes in 3 blocks
==23425== total heap usage: 3,780 allocs, 3,777 frees, 176,188 bytes allocated
==23425==
==23425== 10 bytes in 1 blocks are still reachable in loss record 1 of 3
==23425== at 0x4C2FB0F: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==23425== by 0x50F19B9: strdup (strdup.c:42)
==23425== by 0x4E428B5: ??? (in /usr/lib/x86_64-linux-gnu/libmosquitto.so.1)
==23425== by 0x4E42CEA: mosquitto_connect_bind_v5 (in /usr/lib/x86_64-linux-gnu/libmosquitto.so.1)
==23425== by 0x10ECC6: client_connect (client_shared.c:1201)
==23425== by 0x10A3DF: main (sub_client.c:332)
==23425==
==23425== 24 bytes in 1 blocks are still reachable in loss record 2 of 3
==23425== at 0x4C31B25: calloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==23425== by 0x4E4299D: ??? (in /usr/lib/x86_64-linux-gnu/libmosquitto.so.1)
==23425== by 0x4E42CEA: mosquitto_connect_bind_v5 (in /usr/lib/x86_64-linux-gnu/libmosquitto.so.1)
==23425== by 0x10ECC6: client_connect (client_shared.c:1201)
==23425== by 0x10A3DF: main (sub_client.c:332)
==23425==
==23425== 968 bytes in 1 blocks are still reachable in loss record 3 of 3
==23425== at 0x4C31B25: calloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==23425== by 0x4E4119E: mosquitto_new (in /usr/lib/x86_64-linux-gnu/libmosquitto.so.1)
==23425== by 0x10A363: main (sub_client.c:310)
==23425==
==23425== LEAK SUMMARY:
==23425== definitely lost: 0 bytes in 0 blocks
==23425== indirectly lost: 0 bytes in 0 blocks
==23425== possibly lost: 0 bytes in 0 blocks
==23425== still reachable: 1,002 bytes in 3 blocks
==23425== suppressed: 0 bytes in 0 blocks
==23425==
==23425== For counts of detected and suppressed errors, rerun with: -v
==23425== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)