From 38daca0099ab45b5315f2dfeb1708b0d7976ad5e Mon Sep 17 00:00:00 2001
From: 01zulfi <85733202+01zulfi@users.noreply.github.com>
Date: Mon, 3 Nov 2025 09:01:09 +0500
Subject: [PATCH] editor: fix crash in heading plugin when pasting markdown
 content Signed-off-by: 01zulfi <85733202+01zulfi@users.noreply.github.com>

---
 packages/editor/src/extensions/heading/heading.ts | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/packages/editor/src/extensions/heading/heading.ts b/packages/editor/src/extensions/heading/heading.ts
index b7f73d74f..465e8d471 100644
--- a/packages/editor/src/extensions/heading/heading.ts
+++ b/packages/editor/src/extensions/heading/heading.ts
@@ -365,6 +365,8 @@ const headingUpdatePlugin = new Plugin({
 
     newDoc.descendants((newNode, pos) => {
       if (newNode.type.name === "heading") {
+        if (pos >= oldDoc.content.size) return;
+
         const oldNode = oldDoc.nodeAt(pos);
         if (
           oldNode &&