Fix crashes after 645aaa25b17

WebEngine during page setup can create and delete
accessibility interface with QAccessible::deleteAccessibleInterface,
which will later on tear down end with a crash as lambda function
is called on non existing object.

In case accessibility interface is deleted do not try to call
repair window.

Task-number: QTBUG-108226
Change-Id: Ic052d1b6c9c60168fb32f81134263fc484ee654b
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
(cherry picked from commit dac453a5eb10e1cbf706134bbefdef4564e8b27f)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

2 files changed, 9 insertions, 3 deletions

diff --git a/src/quickwidgets/qaccessiblequickwidget.cpp b/src/quickwidgets/qaccessiblequickwidget.cpp
index 103afda054..40b8f8daf2 100644
--- a/src/quickwidgets/qaccessiblequickwidget.cpp
+++ b/src/quickwidgets/qaccessiblequickwidget.cpp
@@ -19,6 +19,11 @@ QAccessibleQuickWidget::QAccessibleQuickWidget(QQuickWidget* widget)
     repairWindow();
 }
 
+QAccessibleQuickWidget::~QAccessibleQuickWidget()
+{
+    QObject::disconnect(m_connection);
+}
+
 void QAccessibleQuickWidget::repairWindow()
 {
     if (!m_accessibleWindow || !m_accessibleWindow->object()) {
@@ -28,9 +33,8 @@ void QAccessibleQuickWidget::repairWindow()
         // not the one getting destroyed right now.
         if (qobject_cast<QQuickWindow *>(newOffscreen)) {
             m_accessibleWindow.reset(new QAccessibleQuickWindow(newOffscreen));
-            QObject::connect(newOffscreen, &QObject::destroyed, theWidget, [this]{
-                repairWindow();
-            });
+            m_connection = QObject::connect(newOffscreen, &QObject::destroyed, theWidget,
+                                            [this] { repairWindow(); });
         }
     }
 }
diff --git a/src/quickwidgets/qaccessiblequickwidget_p.h b/src/quickwidgets/qaccessiblequickwidget_p.h
index b81a57ba3f..a0c99b7d97 100644
--- a/src/quickwidgets/qaccessiblequickwidget_p.h
+++ b/src/quickwidgets/qaccessiblequickwidget_p.h
@@ -31,6 +31,7 @@ class QAccessibleQuickWidget: public QAccessibleWidget
 {
 public:
     QAccessibleQuickWidget(QQuickWidget* widget);
+    ~QAccessibleQuickWidget();
 
     QAccessibleInterface *child(int index) const override;
     int childCount() const override;
@@ -41,6 +42,7 @@ private:
     void repairWindow();
 
     std::unique_ptr<QAccessibleQuickWindow> m_accessibleWindow;
+    QMetaObject::Connection m_connection;
     Q_DISABLE_COPY(QAccessibleQuickWidget)
 };