fixes #552 - UDP.begin/write now return expected values.

CHANGELOG.md

@@ -35,6 +35,7 @@
  - `TCPClient::stop()` does not work on first connection [#536](https://github.com/spark/firmware/issues/536)
  - `TCPClient::connect()` does not close an existing socket. [#538](https://github.com/spark/firmware/issues/538)
  - TX/RX PWM randomly inverted [#545](https://github.com/spark/firmware/issues/545)
+ - UDP.begin/write return values [#552](https://github.com/spark/firmware/issues/552)
 
 ## v0.4.3
 

hal/inc/socket_hal.h

@@ -68,6 +68,16 @@ sock_result_t socket_receivefrom(sock_handle_t sd, void* buffer, socklen_t len,
 
 sock_result_t socket_send(sock_handle_t sd, const void* buffer, socklen_t len);
 
+/**
+ *
+ * @param sd        The socket handle to send
+ * @param buffer
+ * @param len
+ * @param flags
+ * @param addr
+ * @param addr_size
+ * @return Return the number of bytes sent or a negative value on error.
+ */
 sock_result_t socket_sendto(sock_handle_t sd, const void* buffer, socklen_t len, uint32_t flags, sockaddr_t* addr, socklen_t addr_size);
 
 sock_result_t socket_close(sock_handle_t sd);

hal/src/photon/socket_hal.cpp

@@ -939,9 +939,11 @@ sock_result_t socket_sendto(sock_handle_t sd, const void* buffer, socklen_t len,
             /* Set the end of the data portion */
             wiced_packet_set_data_end(packet, (uint8_t*) data + size);
             result = wiced_udp_send(udp(socket), &ip_addr, port, packet);
+            len = size;
         }
     }
-    return as_sock_result(result);
+    // return negative value on error, or length if successful.
+    return result ? -result : len;
 }
 
 sock_result_t socket_receivefrom(sock_handle_t sd, void* buffer, socklen_t bufLen, uint32_t flags, sockaddr_t* addr, socklen_t* addrsize)