EthernetServer: return EthernetClient(nullptr) when invalid

Author: pschatzmann

ArduinoCore-Linux/cores/arduino/EthernetServer.h

@@ -172,15 +172,15 @@ class EthernetServer : public Server {
     // non blocking check if we have any request to accept
     if (!is_blocking) {
       if (poll_rc <= 0 || !(pfd.revents & POLLIN)) {
-        EthernetClient result;
+        EthernetClient result(nullptr);
         return result;
       }
     }
 
     // accept client connection (blocking call)
     if ((client_fd = ::accept(server_fd, (struct sockaddr*)&client_addr,
                               &client_addr_len)) < 0) {
-      EthernetClient result;
+      EthernetClient result(nullptr);
       Logger.error("accept failed");
       return result;
     }