From bf1af49690151061ba60347ab0ee6a736a466dce Mon Sep 17 00:00:00 2001
From: arold0 <arold0@icloud.com>
Date: Fri, 3 Oct 2025 23:07:13 +0200
Subject: [PATCH] Fix fatal error when double clicking Add button

Prevent adding a note that has already been added by checking if
note.id is set before attempting to add it. This fixes a race
condition when the Add button is clicked multiple times quickly.

Fixes #4376
---
 CONTRIBUTORS       | 1 +
 qt/aqt/addcards.py | 4 ++++
 2 files changed, 5 insertions(+)

diff --git a/CONTRIBUTORS b/CONTRIBUTORS
index 7d44671ca..a18833b04 100644
--- a/CONTRIBUTORS
+++ b/CONTRIBUTORS
@@ -249,6 +249,7 @@ Toby Penner <tobypenner01@gmail.com>
 Danilo Spillebeen <spillebeendanilo@gmail.com>
 Matbe766 <matildabergstrom01@gmail.com>
 Amanda Sternberg <mandis.sternberg@gmail.com>
+arold0 <arold0@icloud.com>
 
 
 ********************
diff --git a/qt/aqt/addcards.py b/qt/aqt/addcards.py
index a27d86234..01d7423d8 100644
--- a/qt/aqt/addcards.py
+++ b/qt/aqt/addcards.py
@@ -289,6 +289,10 @@ class AddCards(QMainWindow):
     def _add_current_note(self) -> None:
         note = self.editor.note
 
+        # Prevent adding a note that has already been added (e.g., from double-clicking)
+        if note.id != 0:
+            return
+
         if not self._note_can_be_added(note):
             return