From b18720d72a6a9d98c7eedf812a885a836b7b9140 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Sun, 14 Dec 2025 02:47:59 +0000
Subject: [PATCH 1/3] Initial plan


From 2c2bdce10568a81d7cb8514f3b1d6580bb7f94c7 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Sun, 14 Dec 2025 02:54:50 +0000
Subject: [PATCH 2/3] Add global error handler for CodeMirror DOM position
 errors

Co-authored-by: curran <68416+curran@users.noreply.github.com>
---
 src/client/main.jsx | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/src/client/main.jsx b/src/client/main.jsx
index 80eb1f2d..28383c65 100644
--- a/src/client/main.jsx
+++ b/src/client/main.jsx
@@ -3,6 +3,29 @@ import * as ReactDOM from 'react-dom/client';
 import App from './App';
 import { BrowserRouter } from 'react-router-dom';
 
+// Global error handler to catch CodeMirror DOM position errors
+// These can occur when CodeMirror instances are created but not yet
+// attached to the DOM, or when presence indicators try to render
+// on offscreen editor instances.
+window.addEventListener('error', (event) => {
+  // Check if this is the specific CodeMirror posFromDOM/posAtDOM error
+  if (
+    event.error instanceof RangeError &&
+    event.error.message.includes(
+      'Trying to find position for a DOM position outside of the document',
+    )
+  ) {
+    // Log the error for debugging purposes
+    console.log(
+      'Suppressed CodeMirror DOM position error:',
+      event.error,
+    );
+    // Prevent the error from propagating
+    event.preventDefault();
+    return true;
+  }
+});
+
 ReactDOM.createRoot(document.getElementById('root')).render(
   <BrowserRouter>
     <App />

From 4838d3025b30cc92e064341ea98ead10142c7f42 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Sun, 14 Dec 2025 02:57:30 +0000
Subject: [PATCH 3/3] Remove unnecessary event.preventDefault() from error
 handler

Co-authored-by: curran <68416+curran@users.noreply.github.com>
---
 src/client/main.jsx | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/src/client/main.jsx b/src/client/main.jsx
index 28383c65..434e42ee 100644
--- a/src/client/main.jsx
+++ b/src/client/main.jsx
@@ -20,8 +20,7 @@ window.addEventListener('error', (event) => {
       'Suppressed CodeMirror DOM position error:',
       event.error,
     );
-    // Prevent the error from propagating
-    event.preventDefault();
+    // Prevent the error from being logged to console by returning true
     return true;
   }
 });