Make password argument to connect optional

If no password is supplied, don't send the PASS command at all.

Signed-off-by: John Else <john.else@citrix.com>

lib/irc_client.ml

@@ -40,21 +40,25 @@ module Make(Io: Irc_transport.IO) = struct
     send_raw ~connection
       ~data:(Printf.sprintf "USER %s %i * :%s" username mode realname)
 
-  let connect ~addr ~port ~username ~mode ~realname ~nick ~password =
+  let connect ~addr ~port ~username ~mode ~realname ~nick ?password () =
     Io.open_socket addr port >>= (fun sock ->
-      let connection = {sock = sock} in
-      send_pass ~connection ~password
+      let connection = {sock = sock} in begin
+        match password with
+        | Some password -> send_pass ~connection ~password
+        | None -> return ()
+      end
       >>= (fun () -> send_nick ~connection ~nick)
       >>= (fun () -> send_user ~connection ~username ~mode ~realname)
       >>= (fun () -> return connection))
 
-  let connect_by_name ~server ~port ~username ~mode ~realname ~nick ~password =
+  let connect_by_name ~server ~port ~username ~mode
+      ~realname ~nick ?password () =
     Io.gethostbyname server >>= fun addr_list ->
     match addr_list with
     | [] -> Io.return None
     | addr ::_ ->
-      connect ~addr ~port ~username ~mode ~realname ~nick ~password >>= fun c ->
-      Io.return (Some c)
+      connect ~addr ~port ~username ~mode ~realname ~nick ?password ()
+      >>= fun c -> Io.return (Some c)
 
   let listen ~connection ~callback =
     let read_length = 1024 in

lib/irc_client.mli

@@ -13,10 +13,11 @@ module Make : functor (Io: Irc_transport.IO) ->
       username:string -> mode:int -> realname:string -> unit Io.t
 
     val connect : addr:Io.inet_addr -> port:int -> username:string -> mode:int ->
-      realname:string -> nick:string -> password:string -> connection_t Io.t
+      realname:string -> nick:string -> ?password:string -> unit ->
+      connection_t Io.t
 
     val connect_by_name : server:string -> port:int -> username:string ->
-      mode:int -> realname:string -> nick:string -> password:string ->
+      mode:int -> realname:string -> nick:string -> ?password:string -> unit ->
       connection_t option Io.t
       (** Try to resolve the [server] name using DNS, otherwise behaves like
           {!connect}. Returns [None] if no IP could be found for the given