From 5cda2125d8434348266811409da8070118d00a61 Mon Sep 17 00:00:00 2001
From: John Factotum <50942278+johnfactotum@users.noreply.github.com>
Date: Mon, 15 Jul 2024 00:08:50 +0800
Subject: [PATCH] MOBI6: empty string instead of undefined in TOC

Should fix https://github.com/johnfactotum/foliate/issues/1347
---
 mobi.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mobi.js b/mobi.js
index bc5b988..86bc994 100644
--- a/mobi.js
+++ b/mobi.js
@@ -720,7 +720,7 @@ class MOBI6 {
                     .reduce((arr, a) => {
                         const indent = getIndent(a)
                         const item = {
-                            label: a.innerText?.trim(),
+                            label: a.innerText?.trim() ?? '',
                             href: `filepos:${a.getAttribute('filepos')}`,
                         }
                         const level = indent > lastIndent ? lastLevel + 1