From cd394a1f6e3e00f9b33e82b3db3dfc80e865bd29 Mon Sep 17 00:00:00 2001
From: Přemysl Janouch <p.janouch@gmail.com>
Date: Sun, 14 Jun 2015 18:33:55 +0200
Subject: degesch: ask for CAP multi-prefix, invite-notify

---
 degesch.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 47 insertions(+), 4 deletions(-)

diff --git a/degesch.c b/degesch.c
index 16aa500..cbeaad1 100644
--- a/degesch.c
+++ b/degesch.c
@@ -3415,6 +3415,10 @@ irc_register (struct server *s)
 	const char *realname = get_config_string (s->config, "realname");
 	hard_assert (nickname && username && realname);
 
+	// Start IRCv3.1 capability negotiation;
+	// at worst the server will ignore this or send a harmless error message
+	irc_send (s, "CAP LS");
+
 	const char *password = get_config_string (s->config, "password");
 	if (password)
 		irc_send (s, "PASS :%s", password);
@@ -4040,6 +4044,48 @@ irc_handle_mode_user (struct server *s, char **params)
 
 // --- Input handling ----------------------------------------------------------
 
+static void
+irc_handle_cap (struct server *s, const struct irc_message *msg)
+{
+	if (msg->params.len < 2)
+		return;
+
+	struct str_vector v;
+	str_vector_init (&v);
+
+	if (msg->params.len > 2)
+		split_str_ignore_empty (msg->params.vector[2], ' ', &v);
+
+	const char *subcommand = msg->params.vector[1];
+	if (!strcasecmp_ascii (subcommand, "ACK")
+	 || !strcasecmp_ascii (subcommand, "NAK"))
+	{
+		// So far we don't need to take any other actions
+		irc_send (s, "CAP END");
+	}
+	else if (!strcasecmp_ascii (subcommand, "LS"))
+	{
+		struct str_vector chosen;
+		str_vector_init (&chosen);
+
+		// Filter server capabilities for ones we can make use of
+		for (size_t i = 0; i < v.len; i++)
+		{
+			const char *cap = v.vector[i];
+			if (!strcasecmp_ascii (cap, "multi-prefix")
+			 || !strcasecmp_ascii (cap, "invite-notify"))
+				str_vector_add (&chosen, cap);
+		}
+
+		char *chosen_str = join_str_vector (&chosen, ' ');
+		str_vector_free (&chosen);
+		irc_send (s, "CAP REQ :%s", chosen_str);
+		free (chosen_str);
+	}
+
+	str_vector_free (&v);
+}
+
 static void
 irc_handle_invite (struct server *s, const struct irc_message *msg)
 {
@@ -4630,6 +4676,7 @@ static struct irc_handler
 g_irc_handlers[] =
 {
 	// This list needs to stay sorted
+	{ "CAP",     irc_handle_cap     },
 	{ "INVITE",  irc_handle_invite  },
 	{ "JOIN",    irc_handle_join    },
 	{ "KICK",    irc_handle_kick    },
@@ -5128,10 +5175,6 @@ irc_handle_rpl_isupport (struct server *s, const struct irc_message *msg)
 			irc_handle_isupport_statusmsg   (s, value_unescaped.str);
 		else if (!strcmp (param, "CHANMODES"))
 			irc_handle_isupport_chanmodes   (s, value_unescaped.str);
-		else if (!strcmp (param, "NAMESX"))
-			// We support receiving multiple mode chars in RPL_NAMREPLY
-			// TODO: get rid of this and instead implement CAP negotiation
-			irc_send (s, "PROTOCTL NAMESX");
 
 		// TODO: also parse MODES, TARGMAX and make use of them
 		//   to split client commands as necessary
-- 
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