From 54c5d35193b683df0995e625b13221b737541978 Mon Sep 17 00:00:00 2001
From: Val Lorentz <progval+github@progval.net>
Date: Sat, 10 Jul 2021 11:11:02 +0200
Subject: [PATCH 1/2] Add support for KICK #chan user1,user2

This is one of the two cases of [RFC 2812 kicks](https://datatracker.ietf.org/doc/html/rfc2812#section-3.2.8):
even when there are multiple user targets, the RFC (and Unreal
and Inspircd and probably others) allows a single channel name.
---
 irc/handlers.go | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/irc/handlers.go b/irc/handlers.go
index 47f16652..697282e2 100644
--- a/irc/handlers.go
+++ b/irc/handlers.go
@@ -1273,11 +1273,12 @@ func sajoinHandler(server *Server, client *Client, msg ircmsg.Message, rb *Respo
 }
 
 // KICK <channel>{,<channel>} <user>{,<user>} [<comment>]
+// The number of channels must be either 1 or equal to the number of users
 func kickHandler(server *Server, client *Client, msg ircmsg.Message, rb *ResponseBuffer) bool {
 	hasPrivs := client.HasRoleCapabs("samode")
 	channels := strings.Split(msg.Params[0], ",")
 	users := strings.Split(msg.Params[1], ",")
-	if (len(channels) != len(users)) && (len(users) != 1) {
+	if (len(channels) != len(users)) && (len(users) != 1) && (len(channels) != 1) {
 		rb.Add(nil, server.name, ERR_NEEDMOREPARAMS, client.nick, "KICK", client.t("Not enough parameters"))
 		return false
 	}
@@ -1286,16 +1287,16 @@ func kickHandler(server *Server, client *Client, msg ircmsg.Message, rb *Respons
 		channel string
 		nick    string
 	}
-	kicks := make([]kickCmd, 0, len(channels))
-	for index, channel := range channels {
+	kicks := make([]kickCmd, 0, len(users))
+	channel := channels[0]
+	for index, user := range users {
+		if len(channels) > 1 {
+			channel = channels[index]
+		}
 		if channel == "" {
 			continue // #679
 		}
-		if len(users) == 1 {
-			kicks = append(kicks, kickCmd{channel, users[0]})
-		} else {
-			kicks = append(kicks, kickCmd{channel, users[index]})
-		}
+		kicks = append(kicks, kickCmd{channel, user})
 	}
 
 	var comment string

From f58f8531b2c171cc1fec04d7ffbfb7e2a312b79c Mon Sep 17 00:00:00 2001
From: Valentin Lorentz <progval+git@progval.net>
Date: Sat, 10 Jul 2021 17:36:39 +0200
Subject: [PATCH 2/2] Restore support for multiple channels + single user

---
 irc/handlers.go | 35 ++++++++++++++++++++++++++---------
 1 file changed, 26 insertions(+), 9 deletions(-)

diff --git a/irc/handlers.go b/irc/handlers.go
index 697282e2..b45cd80e 100644
--- a/irc/handlers.go
+++ b/irc/handlers.go
@@ -1273,7 +1273,9 @@ func sajoinHandler(server *Server, client *Client, msg ircmsg.Message, rb *Respo
 }
 
 // KICK <channel>{,<channel>} <user>{,<user>} [<comment>]
-// The number of channels must be either 1 or equal to the number of users
+// RFC 2812 requires the number of channels to be either 1 or equal to
+// the number of users.
+// Addditionally, we support multiple channels and a single user.
 func kickHandler(server *Server, client *Client, msg ircmsg.Message, rb *ResponseBuffer) bool {
 	hasPrivs := client.HasRoleCapabs("samode")
 	channels := strings.Split(msg.Params[0], ",")
@@ -1287,16 +1289,31 @@ func kickHandler(server *Server, client *Client, msg ircmsg.Message, rb *Respons
 		channel string
 		nick    string
 	}
-	kicks := make([]kickCmd, 0, len(users))
-	channel := channels[0]
-	for index, user := range users {
-		if len(channels) > 1 {
-			channel = channels[index]
+	var kicks []kickCmd
+	if len(users) == 1 {
+		kicks = make([]kickCmd, 0, len(channels))
+		// Single user, possibly multiple channels
+		user := users[0]
+		for _, channel := range channels {
+			if channel == "" {
+				continue // #679
+			}
+			kicks = append(kicks, kickCmd{channel, user})
 		}
-		if channel == "" {
-			continue // #679
+	} else {
+		// Multiple users, either a single channel or as many channels
+		// as users.
+		kicks = make([]kickCmd, 0, len(users))
+		channel := channels[0]
+		for index, user := range users {
+			if len(channels) > 1 {
+				channel = channels[index]
+			}
+			if channel == "" {
+				continue // #679
+			}
+			kicks = append(kicks, kickCmd{channel, user})
 		}
-		kicks = append(kicks, kickCmd{channel, user})
 	}
 
 	var comment string