From 1cdc2045c753d691a54a825641212f32f1a2a4b1 Mon Sep 17 00:00:00 2001
From: Christian Rocha <christian@rocha.is>
Date: Fri, 19 Jun 2020 19:46:51 -0400
Subject: [PATCH] Fix a potential out of bounds panic

---
 viewport/viewport.go | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/viewport/viewport.go b/viewport/viewport.go
index 289e03d..4c2db8b 100644
--- a/viewport/viewport.go
+++ b/viewport/viewport.go
@@ -197,6 +197,10 @@ func (m *Model) LineUp(n int) (lines []string) {
 // COMMANDS
 
 func Sync(m Model) tea.Cmd {
+	if len(m.lines) == 0 {
+		return nil
+	}
+
 	top := max(m.YOffset, 0)
 	bottom := min(m.YOffset+m.Height, len(m.lines)-1)