degesch: "nickname" -> "nicks"

Now you can specify multiple nicknames to try.

degesch.c

@@ -1138,6 +1138,7 @@ struct server
 	struct str_map irc_buffer_map;      ///< Maps IRC identifiers to buffers
 
 	struct user *irc_user;              ///< Our own user
+	int nick_counter;                   ///< Iterates "nicks" when registering
 	struct str irc_user_mode;           ///< Our current user modes
 	char *irc_user_host;                ///< Our current user@host
 
@@ -1488,9 +1489,9 @@ config_validate_nonnegative
 
 static struct config_schema g_config_server[] =
 {
-	{ .name      = "nickname",
+	{ .name      = "nicks",
 	  .comment   = "IRC nickname",
-	  .type      = CONFIG_ITEM_STRING,
+	  .type      = CONFIG_ITEM_STRING_ARRAY,
 	  .validate  = config_validate_nonjunk_string },
 	{ .name      = "username",
 	  .comment   = "IRC user name",
@@ -4003,11 +4004,11 @@ static struct transport g_transport_tls =
 static bool
 irc_autofill_user_info (struct server *s, struct error **e)
 {
-	const char *nickname = get_config_string (s->config, "nickname");
+	const char *nicks    = get_config_string (s->config, "nicks");
 	const char *username = get_config_string (s->config, "username");
 	const char *realname = get_config_string (s->config, "realname");
 
-	if (nickname && username && realname)
+	if (nicks && *nicks && username && *username && realname)
 		return true;
 
 	// Read POSIX user info and fill the configuration if needed
@@ -4016,9 +4017,9 @@ irc_autofill_user_info (struct server *s, struct error **e)
 		FAIL ("cannot retrieve user information: %s", strerror (errno));
 
 	// FIXME: set_config_strings() writes errors on its own
-	if (!nickname)
+	if (!nicks    || !*nicks)
-		set_config_string (s->config, "nickname", pwd->pw_name);
+		set_config_string (s->config, "nicks",    pwd->pw_name);
-	if (!username)
+	if (!username || !*username)
 		set_config_string (s->config, "username", pwd->pw_name);
 
 	// Not all systems have the GECOS field but the vast majority does
@@ -4037,16 +4038,33 @@ irc_autofill_user_info (struct server *s, struct error **e)
 	return true;
 }
 
+static char *
+irc_fetch_next_nickname (struct server *s)
+{
+	struct str_vector v;
+	str_vector_init (&v);
+	split_str_ignore_empty (get_config_string (s->config, "nicks"), ',', &v);
+
+	char *result = NULL;
+	if (s->nick_counter >= 0 && s->nick_counter < v.len)
+		result = str_vector_steal (&v, s->nick_counter++);
+	if (s->nick_counter >= v.len)
+		// Exhausted all nicknames
+		s->nick_counter = -1;
+
+	str_vector_free (&v);
+	return result;
+}
+
 static void
 irc_register (struct server *s)
 {
 	// Fill in user information automatically if needed
 	irc_autofill_user_info (s, NULL);
 
-	const char *nickname = get_config_string (s->config, "nickname");
 	const char *username = get_config_string (s->config, "username");
 	const char *realname = get_config_string (s->config, "realname");
-	hard_assert (nickname && username && realname);
+	hard_assert (username && realname);
 
 	// Start IRCv3.1 capability negotiation;
 	// at worst the server will ignore this or send a harmless error message
@@ -4056,7 +4074,15 @@ irc_register (struct server *s)
 	if (password)
 		irc_send (s, "PASS :%s", password);
 
-	irc_send (s, "NICK %s", nickname);
+	s->nick_counter = 0;
+
+	char *nickname = irc_fetch_next_nickname (s);
+	if (nickname)
+		irc_send (s, "NICK :%s", nickname);
+	else
+		log_server_error (s, s->buffer, "No nicks present in configuration");
+	free (nickname);
+
 	// IRC servers may ignore the last argument if it's empty
 	irc_send (s, "USER %s 8 * :%s", username, *realname ? realname : " ");
 }
@@ -5647,6 +5673,28 @@ irc_handle_rpl_inviting (struct server *s, const struct irc_message *msg)
 		"You have invited #n to #S", nickname, channel_name);
 }
 
+static void
+irc_handle_err_nicknameinuse (struct server *s, const struct irc_message *msg)
+{
+	if (msg->params.len < 2)
+		return;
+
+	log_server_error (s, s->buffer,
+		"Nickname is already in use: #S", msg->params.vector[1]);
+
+	// Only do this while we haven't successfully registered yet
+	if (s->state != IRC_CONNECTED)
+		return;
+
+	char *nickname = irc_fetch_next_nickname (s);
+	if (nickname)
+	{
+		log_server_status (s, s->buffer, "Retrying with #s...", nickname);
+		irc_send (s, "NICK :%s", nickname);
+		free (nickname);
+	}
+}
+
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 
 static void
@@ -5848,9 +5896,7 @@ irc_process_numeric (struct server *s,
 		irc_handle_rpl_inviting      (s, msg); buffer = NULL; break;
 
 	case IRC_ERR_NICKNAMEINUSE:
-		// TODO: if (state == IRC_CONNECTED), use a different nick;
+		irc_handle_err_nicknameinuse (s, msg); buffer = NULL; break;
-		//   either use a number suffix, or accept commas in "nickname" config
-		break;
 
 	case IRC_RPL_LIST:
 	case IRC_RPL_WHOREPLY: