From bb451a5050e5083b516d3eebce94deb15a666ddd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?P=C5=99emysl=20Eric=20Janouch?= <p@janouch.name>
Date: Fri, 28 May 2021 01:44:46 +0200
Subject: [PATCH] degesch: support CAP DEL, request cap-notify

It doesn't require much effort to cancel capabilities, plus with
the newer version we get the respective notification anyway.
---
 NEWS      |  2 +-
 degesch.c | 23 ++++++++++++++++++-----
 2 files changed, 19 insertions(+), 6 deletions(-)

diff --git a/NEWS b/NEWS
index 5ccd44c..8c56d81 100644
--- a/NEWS
+++ b/NEWS
@@ -2,7 +2,7 @@
 
  * degesch: added a /squery command for IRCnet
 
- * degesch: now supporting IRCv3.2 capability negotiation
+ * degesch: now supporting IRCv3.2 capability negotiation, including CAP DEL
 
 
 1.1.0 (2020-10-31) "What Do You Mean By 'This Isn't Germany'?"
diff --git a/degesch.c b/degesch.c
index 563da0f..eaf71fa 100644
--- a/degesch.c
+++ b/degesch.c
@@ -2340,7 +2340,7 @@ static struct config_schema g_config_server[] =
 	  .type      = CONFIG_ITEM_STRING_ARRAY,
 	  .validate  = config_validate_nonjunk_string,
 	  .default_  = "\"multi-prefix,invite-notify,server-time,echo-message,"
-		"message-tags,away-notify\"" },
+		"message-tags,away-notify,cap-notify\"" },
 
 	{ .name      = "tls",
 	  .comment   = "Whether to use TLS",
@@ -6576,6 +6576,15 @@ irc_process_cap_ls (struct server *s)
 	free (chosen_str);
 }
 
+static void
+irc_toggle_cap (struct server *s, const char *cap, bool active)
+{
+	if (!strcasecmp_ascii (cap, "echo-message"))
+		s->cap_echo_message = active;
+	if (!strcasecmp_ascii (cap, "away-notify"))
+		s->cap_away_notify  = active;
+}
+
 static void
 irc_handle_cap (struct server *s, const struct irc_message *msg)
 {
@@ -6601,10 +6610,7 @@ irc_handle_cap (struct server *s, const struct irc_message *msg)
 				active = false;
 				cap++;
 			}
-			if (!strcasecmp_ascii (cap, "echo-message"))
-				s->cap_echo_message = active;
-			if (!strcasecmp_ascii (cap, "away-notify"))
-				s->cap_away_notify = active;
+			irc_toggle_cap (s, cap, active);
 		}
 		irc_send (s, "CAP END");
 	}
@@ -6614,6 +6620,13 @@ irc_handle_cap (struct server *s, const struct irc_message *msg)
 			"#s: #S", "Capabilities not acknowledged", args);
 		irc_send (s, "CAP END");
 	}
+	else if (!strcasecmp_ascii (subcommand, "DEL"))
+	{
+		log_server_error (s, s->buffer,
+			"#s: #S", "Capabilities deleted", args);
+		for (size_t i = 0; i < v.len; i++)
+			irc_toggle_cap (s, v.vector[i], false);
+	}
 	else if (!strcasecmp_ascii (subcommand, "LS"))
 	{