From dcfb49585d71e0c02cf2aa8ef38b0b689a1eafec Mon Sep 17 00:00:00 2001
From: nmemmert <67961292+nmemmert@users.noreply.github.com>
Date: Wed, 29 Jul 2026 17:23:03 -0400
Subject: [PATCH] Fix docx import crash on large files by chunking base64
 encoding

btoa(String.fromCharCode(...new Uint8Array(buf))) exceeds V8's function
argument stack limit for files larger than ~65k bytes. Process in 8k
chunks instead to handle any file size.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
---
 public/admin.js | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/public/admin.js b/public/admin.js
index 5c581dc..51f8bf5 100644
--- a/public/admin.js
+++ b/public/admin.js
@@ -611,7 +611,12 @@ $('#import-go-btn').addEventListener('click', async () => {
   $('#import-status').textContent = '🔍 Extracting content… this may take a minute.';
   try {
     const arrayBuffer = await file.arrayBuffer();
-    const base64 = btoa(String.fromCharCode(...new Uint8Array(arrayBuffer)));
+    const bytes = new Uint8Array(arrayBuffer);
+    let binary = '';
+    for (let i = 0; i < bytes.length; i += 8192) {
+      binary += String.fromCharCode(...bytes.subarray(i, Math.min(i + 8192, bytes.length)));
+    }
+    const base64 = btoa(binary);
     const result = await api('/api/admin/import-docx', { method: 'POST', body: { base64, mode } });
     if (!$('#ie-title').value && result.title) $('#ie-title').value = result.title;
     if (mode === 'quiz' && result.questions) {