From f51d27860a0214fdc35b7d6649008fefe7ce350e Mon Sep 17 00:00:00 2001
From: Alex Ling <hkalexling@gmail.com>
Date: Sat, 9 Jan 2021 15:49:34 +0000
Subject: [PATCH] Validate input index before flipping page

---
 public/js/reader.js | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/public/js/reader.js b/public/js/reader.js
index c09c340..8bf1133 100644
--- a/public/js/reader.js
+++ b/public/js/reader.js
@@ -101,8 +101,9 @@ const readerComponent = () => {
 		 */
 		flipPage(isNext) {
 			const idx = parseInt(this.curItem.id);
-			const delta = isNext ? 1 : -1;
-			const newIdx = idx + delta;
+			const newIdx = idx + (isNext ? 1 : -1);
+
+			if (newIdx <= 0 || newIdx > this.items.length) return;
 
 			this.toPage(newIdx);