[649] Don't close socket again if nonblock fails.

Thanks to Edwin van den Oetelaar.

Bug: https://github.com/eclipse/mosquitto/issues/649

ChangeLog.txt

@@ -14,6 +14,7 @@ Client library:
 - Fix incorrect PSK key being used if it had leading zeroes.
 - Initialise "result" variable as soon as possible in
   mosquitto_topic_matches_sub. Closes #654.
+- No need to close socket again if setting non-blocking failed. Closes #649.
 
 Build:
 - Don't run TLS-PSK tests if TLS-PSK disabled at compile time. Closes #636.

lib/net_mosq.c

@@ -329,7 +329,6 @@ int _mosquitto_try_connect_step2(struct mosquitto *mosq, uint16_t port, mosq_soc
 
 		/* Set non-blocking */
 		if(_mosquitto_socket_nonblock(*sock)){
-			COMPAT_CLOSE(*sock);
 			continue;
 		}
 
@@ -344,7 +343,6 @@ int _mosquitto_try_connect_step2(struct mosquitto *mosq, uint16_t port, mosq_soc
 
 			/* Set non-blocking */
 			if(_mosquitto_socket_nonblock(*sock)){
-				COMPAT_CLOSE(*sock);
 				continue;
 			}
 			break;
@@ -429,7 +427,6 @@ int _mosquitto_try_connect(struct mosquitto *mosq, const char *host, uint16_t po
 		if(!blocking){
 			/* Set non-blocking */
 			if(_mosquitto_socket_nonblock(*sock)){
-				COMPAT_CLOSE(*sock);
 				continue;
 			}
 		}
@@ -446,7 +443,6 @@ int _mosquitto_try_connect(struct mosquitto *mosq, const char *host, uint16_t po
 			if(blocking){
 				/* Set non-blocking */
 				if(_mosquitto_socket_nonblock(*sock)){
-					COMPAT_CLOSE(*sock);
 					continue;
 				}
 			}
@@ -1250,7 +1246,6 @@ int _mosquitto_socketpair(mosq_sock_t *pairR, mosq_sock_t *pairW)
 			continue;
 		}
 		if(_mosquitto_socket_nonblock(spR)){
-			COMPAT_CLOSE(spR);
 			COMPAT_CLOSE(listensock);
 			continue;
 		}
@@ -1278,7 +1273,6 @@ int _mosquitto_socketpair(mosq_sock_t *pairR, mosq_sock_t *pairW)
 
 		if(_mosquitto_socket_nonblock(spW)){
 			COMPAT_CLOSE(spR);
-			COMPAT_CLOSE(spW);
 			COMPAT_CLOSE(listensock);
 			continue;
 		}
@@ -1296,13 +1290,11 @@ int _mosquitto_socketpair(mosq_sock_t *pairR, mosq_sock_t *pairW)
 		return MOSQ_ERR_ERRNO;
 	}
 	if(_mosquitto_socket_nonblock(sv[0])){
-		COMPAT_CLOSE(sv[0]);
 		COMPAT_CLOSE(sv[1]);
 		return MOSQ_ERR_ERRNO;
 	}
 	if(_mosquitto_socket_nonblock(sv[1])){
 		COMPAT_CLOSE(sv[0]);
-		COMPAT_CLOSE(sv[1]);
 		return MOSQ_ERR_ERRNO;
 	}
 	*pairR = sv[0];