Fixed socket code constantly throwing exceptions about non-blocking.

OpenRA.Game/Server/Connection.cs

@@ -44,6 +44,11 @@ namespace OpenRA.Server
 			{
 				try
 				{
+					// NOTE(jsd): Poll the socket first to see if there's anything there.
+					// This avoids the exception with SocketErrorCode == `SocketError.WouldBlock` thrown
+					// from `socket.Receive(rx)`.
+					if (!socket.Poll(0, SelectMode.SelectRead)) break;
+
 					if (0 < (len = socket.Receive(rx)))
 						data.AddRange(rx.Take(len));
 					else
@@ -52,11 +57,12 @@ namespace OpenRA.Server
 							server.DropClient(this);
 						break;
 					}
-
 				}
 				catch (SocketException e)
 				{
+					// NOTE(jsd): This should no longer be needed with the socket.Poll call above.
 					if (e.SocketErrorCode == SocketError.WouldBlock) break;
+
 					server.DropClient(this);
 					return false;
 				}