relay: immediately close connection if the handshake failed (weechat protocol)

doc/en/weechat_relay_protocol.en.adoc

@@ -149,7 +149,8 @@ WeeChat replies with a hashtable containing the following keys and values:
 
 * _password_hash_algo_: the password authentication negotiated: supported by
   both the client and _relay_:
-** (empty value): negotiation failed, password authentication is *NOT* possible
+** (empty value): negotiation failed, password authentication is *NOT* possible;
+   in this case the connection with the client is immediately closed
 ** _plain_
 ** _sha256_
 ** _sha512_

doc/fr/weechat_relay_protocol.fr.adoc

@@ -158,7 +158,8 @@ suivantes :
 * _password_hash_algo_ : l'authentification mot de passe négociée : supportée
   par le client et _relay_ :
 ** (valeur vide) : la négociation a échoué, l'authentification par mot de passe
-   n'est *PAS* possible
+   n'est *PAS* possible ; dans ce cas la connexion avec le client est
+   immédiatement fermée
 ** _plain_
 ** _sha256_
 ** _sha512_

doc/ja/weechat_relay_protocol.ja.adoc

@@ -158,7 +158,8 @@ WeeChat replies with a hashtable containing the following keys and values:
 
 * _password_hash_algo_: the password authentication negotiated: supported by
   both the client and _relay_:
-** (empty value): negotiation failed, password authentication is *NOT* possible
+** (empty value): negotiation failed, password authentication is *NOT* possible;
+   in this case the connection with the client is immediately closed
 ** _plain_
 ** _sha256_
 ** _sha512_

src/plugins/relay/weechat/relay-weechat-protocol.c

@@ -304,6 +304,10 @@ RELAY_WEECHAT_PROTOCOL_CALLBACK(handshake)
 
     relay_weechat_protocol_handshake_reply (client, id);
 
+    /* if no algo was found, we close the connection immediately */
+    if (client->password_hash_algo < 0)
+        relay_client_set_status (client, RELAY_STATUS_AUTH_FAILED);
+
     return WEECHAT_RC_OK;
 }