From 0165793b3ee6f126e152199362f8d131e116c797 Mon Sep 17 00:00:00 2001
From: Christian Vidal Wolf <christianvidalwolf@gmail.com>
Date: Thu, 23 Apr 2026 16:47:39 +0200
Subject: [PATCH] fix: fill sparse holes in extendedHeaders to prevent
 undefined.includes() crash

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
---
 src/App.tsx | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/App.tsx b/src/App.tsx
index 66d7af2..22d0b57 100644
--- a/src/App.tsx
+++ b/src/App.tsx
@@ -154,6 +154,10 @@ export default function App() {
               extendedHeaders[idx] = name;
             }
           });
+          // Fill any sparse holes with '' to avoid undefined.includes() errors
+          for (let i = 0; i < extendedHeaders.length; i++) {
+            if (extendedHeaders[i] === undefined) extendedHeaders[i] = '';
+          }
 
           const resolvedCols = resolveColumnIndices(extendedHeaders);
           const editableColumns = new Set([