Fix endPacket() return value if socket is unbound

The endPacket() method returns 0 (failure) only in the case where WiFiSocket.sendto() returns < 0. However, the sendto() method returns exactly 0 in the case where the socket is not in a BOUND state. This allows endPacket() to indicate success after sendto() indicates failure. The simple fix is to change the condition to be <= 0 instead of < 0.

Author: jrowberg

src/WiFiUdp.cpp

@@ -137,7 +137,7 @@ int WiFiUDP::endPacket()
 
 	int result = WiFiSocket.sendto(_socket, (void *)_sndBuffer, _sndSize, 0, (struct sockaddr *)&addr, sizeof(addr));
 
-	return (result < 0) ? 0 : 1;
+	return (result <= 0) ? 0 : 1;
 }
 
 size_t WiFiUDP::write(uint8_t byte)