bound textbox input to prevent unbounded memory growth

uiterm/textbox.go

@@ -7,6 +7,8 @@ import (
 	"github.com/nsf/termbox-go"
 )
 
+const maxTextboxLen = 2000
+
 type Textbox struct {
 	Text   string
 	Fg, Bg Attribute
@@ -71,8 +73,10 @@ func (t *Textbox) uiKeyEvent(mod Modifier, key Key) {
 		t.Text = ""
 		redraw = true
 	case KeySpace:
-		t.Text = t.Text + " "
+		if len(t.Text) < maxTextboxLen {
-		redraw = true
+			t.Text = t.Text + " "
+			redraw = true
+		}
 	case KeyBackspace:
 	case KeyBackspace2:
 		if len(t.Text) > 0 {
@@ -88,6 +92,9 @@ func (t *Textbox) uiKeyEvent(mod Modifier, key Key) {
 }
 
 func (t *Textbox) uiCharacterEvent(chr rune) {
+	if len(t.Text) >= maxTextboxLen {
+		return
+	}
 	t.Text = t.Text + string(chr)
 	t.uiDraw()
 }