From 467df249146cda8cd267934bc6ff63f97d6ad867 Mon Sep 17 00:00:00 2001
From: Shivaram Lingamneni <slingamn@cs.stanford.edu>
Date: Sat, 22 Mar 2025 23:13:31 -0400
Subject: [PATCH] fix #2228 (#2233)

If the server is UTF8ONLY, validate that the MOTD is UTF8
---
 irc/config.go | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/irc/config.go b/irc/config.go
index bbbb8aee..2ad0a97d 100644
--- a/irc/config.go
+++ b/irc/config.go
@@ -22,6 +22,7 @@ import (
 	"strconv"
 	"strings"
 	"time"
+	"unicode/utf8"
 
 	"code.cloudfoundry.org/bytefmt"
 	"github.com/ergochat/irc-go/ircfmt"
@@ -1864,6 +1865,9 @@ func (config *Config) loadMOTD() error {
 			if config.Server.MOTDFormatting {
 				lineToSend = ircfmt.Unescape(lineToSend)
 			}
+			if config.Server.EnforceUtf8 && !utf8.ValidString(lineToSend) {
+				return fmt.Errorf("Line %d of MOTD contains invalid UTF8", i+1)
+			}
 			// "- " is the required prefix for MOTD
 			lineToSend = fmt.Sprintf("- %s", lineToSend)
 			config.Server.motdLines = append(config.Server.motdLines, lineToSend)