Fix undefined behaviour in WiFiServer::setNoDelay (#1695)

Author: igrr

libraries/ESP8266WiFi/src/WiFiServer.cpp

@@ -81,19 +81,11 @@ void WiFiServer::begin() {
 }
 
 void WiFiServer::setNoDelay(bool nodelay) {
-    if (!_pcb)
-      return;
-
-    if (nodelay)
-        tcp_nagle_disable(_pcb);
-    else
-        tcp_nagle_enable(_pcb);
+    _noDelay = nodelay;
 }
 
 bool WiFiServer::getNoDelay() {
-    if (!_pcb)
-        return false;
-    return tcp_nagle_disabled(_pcb);
+    return _noDelay;
 }
 
 bool WiFiServer::hasClient() {
@@ -106,6 +98,7 @@ WiFiClient WiFiServer::available(byte* status) {
     if (_unclaimed) {
         WiFiClient result(_unclaimed);
         _unclaimed = _unclaimed->next();
+        result.setNoDelay(_noDelay);
         DEBUGV("WS:av\r\n");
         return result;
     }

libraries/ESP8266WiFi/src/WiFiServer.h

@@ -42,6 +42,7 @@ class WiFiServer : public Server {
 
   ClientContext* _unclaimed;
   ClientContext* _discarded;
+  bool _noDelay = false;
 
 public:
   WiFiServer(IPAddress addr, uint16_t port);