Packet with zero data length (espressif#1659)

Schuemi · me-no-dev · commit f1f8d7e306bf · 2018-07-24T19:52:42.000+02:00
If you receive a package with a data length of zero, parsePacket returns 0, but rx_buffer will exist. So if another parsePacket with no read access returns to zeros, there is still data that can be read. This example would not work: https://www.arduino.cc/en/Reference/EthernetUDPParsePacket Also I added a check if rx_buffer exit when you try to flush it.
diff --git a/libraries/WiFi/src/WiFiUdp.cpp b/libraries/WiFi/src/WiFiUdp.cpp
@@ -221,6 +221,7 @@ int WiFiUDP::parsePacket(){
   }
   remote_ip = IPAddress(si_other.sin_addr.s_addr);
   remote_port = ntohs(si_other.sin_port);
+  if (len == 0) return 0;
   rx_buffer = new cbuf(len);
   rx_buffer->write(buf, len);
   delete[] buf;
@@ -264,6 +265,7 @@ int WiFiUDP::peek(){
 }
 
 void WiFiUDP::flush(){
+  if(!rx_buffer) return;
   cbuf *b = rx_buffer;
   rx_buffer = 0;
   delete b;

Original file line number	Diff line number	Diff line change
`@@ -221,6 +221,7 @@ int WiFiUDP::parsePacket(){`
`221`	`221`	`}`
`222`	`222`	`remote_ip = IPAddress(si_other.sin_addr.s_addr);`
`223`	`223`	`remote_port = ntohs(si_other.sin_port);`
	`224`	`+ if (len == 0) return 0;`
`224`	`225`	`rx_buffer = new cbuf(len);`
`225`	`226`	`rx_buffer->write(buf, len);`
`226`	`227`	`delete[] buf;`
`@@ -264,6 +265,7 @@ int WiFiUDP::peek(){`
`264`	`265`	`}`
`265`	`266`
`266`	`267`	`void WiFiUDP::flush(){`
	`268`	`+ if(!rx_buffer) return;`
`267`	`269`	`cbuf *b = rx_buffer;`
`268`	`270`	`rx_buffer = 0;`
`269`	`271`	`delete b;`