fix truncation check

* The message target was not being counted :-(
* The additional character added to the target by STATUSMSG was not counted

irc/channel.go

@@ -1320,6 +1320,11 @@ func (channel *Channel) SendSplitMessage(command string, minPrefixMode modes.Mod
 	isBot := client.HasMode(modes.Bot)
 	chname := channel.Name()
 
+	// STATUSMSG targets are prefixed with the supplied min-prefix, e.g., @#channel
+	if minPrefixMode != modes.Mode(0) {
+		chname = fmt.Sprintf("%s%s", modes.ChannelModePrefixes[minPrefixMode], chname)
+	}
+
 	if !client.server.Config().Server.Compatibility.allowTruncation {
 		if !validateSplitMessageLen(histType, details.nickMask, chname, message) {
 			rb.Add(nil, client.server.name, ERR_INPUTTOOLONG, details.nick, client.t("Line too long to be relayed without truncation"))
@@ -1327,11 +1332,6 @@ func (channel *Channel) SendSplitMessage(command string, minPrefixMode modes.Mod
 		}
 	}
 
-	// STATUSMSG targets are prefixed with the supplied min-prefix, e.g., @#channel
-	if minPrefixMode != modes.Mode(0) {
-		chname = fmt.Sprintf("%s%s", modes.ChannelModePrefixes[minPrefixMode], chname)
-	}
-
 	if channel.flags.HasMode(modes.OpModerated) {
 		channel.stateMutex.RLock()
 		cuData, ok := channel.members[client]

irc/handlers.go

@@ -2184,6 +2184,7 @@ func validateLineLen(msgType history.ItemType, source, target, payload string) (
 	default:
 		return true
 	}
+	limit -= len(target)
 	limit -= len(payload)
 	return limit >= 0
 }