Initial events are occasionally failing to be delivered - the tcp con…

…nect attempt from the device stack is never acknowledged by the network stack on the control point. This can cause control point's discovery to fail. Mitigate this by retrying the connect for initial events. See #4469.

OpenHome/Net/Device/Upnp/DviServerUpnp.cpp

@@ -336,9 +336,31 @@ void PropertyWriterUpnp::Connect()
     iSubscriber.AppendAddress(buf);
     Log::Print("PropertyWriterUpnp connecting to %s\n", buf.Ptr());
 #endif
-    iSocket.Open(iEnv);
-    iSocket.Connect(iSubscriber, iEnv.InitParams()->TcpConnectTimeoutMs());
-    //iSocket.LogVerbose(true);
+    static const TUint kInitialEventConnectRetries = 3;
+    TUint retries = (iSequenceNumber == 0? kInitialEventConnectRetries : 0);
+    for (;;) {
+        try {
+            iSocket.Open(iEnv);
+            iSocket.Connect(iSubscriber, iEnv.InitParams()->TcpConnectTimeoutMs());
+            //iSocket.LogVerbose(true);
+            return;
+        }
+        catch (NetworkTimeout&) {
+            if (retries == 0) {
+                throw;
+            }
+        }
+        catch (NetworkError&) {
+            if (retries == 0) {
+                throw;
+            }
+        }
+        --retries;
+        try {
+            iSocket.Close();
+        }
+        catch (NetworkError&) {}
+    }
 }
 
 void PropertyWriterUpnp::WriteHeaders(TUint aContentLength)