fix quit logic; echo QUIT message

lib/server/connection.ml

@@ -171,7 +171,7 @@ let on_msg t (msg : Irc.Msg.t) : unit =
   in
   match result with
   | `ok -> ()
-  | `quit -> close t
+  | `quit -> cleanup t
   | `welcome -> rpl_welcome t; rpl_motd t
   | `names (cp, ch, us) -> rpl_names t cp ch us
   | `tryagain -> rpl_tryagain t msg.command

lib/server/router.ml

@@ -67,8 +67,14 @@ module User = struct
     end
 
   let cleanup t =
+    if is_registered t then begin
+      (* TODO: quit reason *)
+      send t (Irc.Msg.make "QUIT" ["Closed"]
+                ~prefix:(prefix t)
+                ~always_trailing:true);
       (* TODO: relay QUIT message *)
-    unregister t;
+      unregister t
+    end;
     close t
 end