Preserve UTF-8 when truncating input status

client_notification_test.go

@@ -5,6 +5,7 @@ import (
 	"strings"
 	"testing"
 	"time"
+	"unicode/utf8"
 
 	"git.stormux.org/storm/barnard/gumble/gumble"
 )
@@ -57,6 +58,15 @@ func TestNotificationExpansionIsSinglePassAndNotifyDoesNotBlock(t *testing.T) {
 // and renderer resources. Cleanup must be safe for repeated disconnects.
 // Regression: user and channel names in the navigation tree bypassed message
 // escaping and could still carry terminal control characters.
+// Regression: status truncation used byte indexes and could create invalid
+// UTF-8 when a non-ASCII user or channel name exceeded the display limit.
+func TestTruncateInputStatusPreservesUTF8(t *testing.T) {
+	got := truncateInputStatus(strings.Repeat("é", 21))
+	if !utf8.ValidString(got) || utf8.RuneCountInString(got) != 21 {
+		t.Fatalf("invalid truncation %q", got)
+	}
+}
+
 func TestTreeItemSanitizesServerNames(t *testing.T) {
 	item := TreeItem{Channel: &gumble.Channel{Name: "\x1b[2Jroom"}}
 	if got := item.String(); got != "#[2Jroom" {

ui.go

@@ -62,14 +62,21 @@ func (b *Barnard) GetInputStatus() string {
 }
 
 func (b *Barnard) UpdateInputStatus(status string) {
-	if len(status) > 20 {
-		status = status[:17] + "..." + "]"
-	}
+	status = truncateInputStatus(status)
 	b.UiInputStatus.Text = status
 	b.RebuildUserChannelTreePreservingSelection()
 	b.Ui.Refresh()
 }
 
+// truncateInputStatus limits terminal cells without splitting UTF-8 runes.
+func truncateInputStatus(status string) string {
+	chars := []rune(status)
+	if len(chars) > 20 {
+		return string(chars[:17]) + "..." + "]"
+	}
+	return status
+}
+
 func (b *Barnard) AddOutputLine(line string) {
 	now := time.Now()
 	b.UiOutput.AddLine(fmt.Sprintf("%s [%02d:%02d:%02d]", line, now.Hour(), now.Minute(), now.Second()))