From 4c3d906068caafb9ce7170f51f93f0e429469397 Mon Sep 17 00:00:00 2001
From: David Faure <david.faure@kdab.com>
Date: Wed, 28 Feb 2024 16:51:45 +0100
Subject: [PATCH] QDialogButtonBox: fix crash when adding a QToolButton

Introduced by commit d4f38a363251fcb5cdfb24d7a1aceb7b630f7e8f

Pick-to: 6.6 6.5
Change-Id: I99385249a454c75eeae13c1d17670b356427cb70
Reviewed-by: Axel Spoerl <axel.spoerl@qt.io>
(cherry picked from commit d9b63c90bf65d853fa74a1327ef7455e1b655fac)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
---
 src/widgets/widgets/qdialogbuttonbox.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/widgets/widgets/qdialogbuttonbox.cpp b/src/widgets/widgets/qdialogbuttonbox.cpp
index 0ecb97bff7b..545e8bb6dab 100644
--- a/src/widgets/widgets/qdialogbuttonbox.cpp
+++ b/src/widgets/widgets/qdialogbuttonbox.cpp
@@ -294,7 +294,7 @@ void QDialogButtonBoxPrivate::layoutButtons()
         for (QWidget *here : layoutWidgets) {
             QWidget::setTabOrder(prev, here);
             prev = here;
-            if (auto *pushButton = qobject_cast<QPushButton *>(prev); pushButton->isDefault())
+            if (auto *pushButton = qobject_cast<QPushButton *>(prev); pushButton && pushButton->isDefault())
                 q->setFocusProxy(pushButton);
         }
     }