Check for invalid max socket fd before polling

src/connection.c

@@ -59,6 +59,10 @@ connection_new(unsigned int source_port, const char* source_ip, unsigned int des
 struct Connection*
 connection_poll_ready(struct Client* client) {
 
+    // Return a null connection if no sockets have been opened
+    if(max_fds < 0)
+        return NULL;
+
     // Add all the connections' socket file descriptors to a watch list
     fd_set read_fds;
     FD_ZERO(&read_fds);