Allow client to bind on a random port

src/socket.cpp

@@ -53,6 +53,17 @@ void CSocket::Init ( const quint16 iPortNumber )
     bool bSuccess;
 
     if ( bIsClient )
+    {
+        if (iPortNumber == 0)
+        {
+            // If port number is 0, bind the client to a random available port.
+            UdpSocketInAddr.sin_port = htons ( iPortNumber );
+
+            bSuccess = ( ::bind ( UdpSocket ,
+                                (sockaddr*) &UdpSocketInAddr,
+                                sizeof ( sockaddr_in ) ) == 0 );
+        }
+        else
         {
             // Per definition use the port number plus ten for the client to make
             // it possible to run server and client on the same computer. If the
@@ -73,6 +84,7 @@ void CSocket::Init ( const quint16 iPortNumber )
                 iClientPortIncrement++;
             }
         }
+    }
     else
     {
         // for the server, only try the given port number and do not try out