4 files changed, 22 insertions, 17 deletions

diff --git a/src/widgets/kernel/qapplication.cpp b/src/widgets/kernel/qapplication.cpp
index a459a57482..fcc195f601 100644
--- a/src/widgets/kernel/qapplication.cpp
+++ b/src/widgets/kernel/qapplication.cpp
@@ -2249,10 +2249,10 @@ void QApplicationPrivate::notifyActiveWindowChange(QWindow *previous)
     QApplication::setActiveWindow(tlw);
     // QTBUG-37126, Active X controls may set the focus on native child widgets.
     if (wnd && tlw && wnd != tlw->windowHandle()) {
-        if (QWidgetWindow *widgetWindow = qobject_cast<QWidgetWindow *>(wnd)) {
-            if (widgetWindow->widget()->inherits("QAxHostWidget"))
-                widgetWindow->widget()->setFocus(Qt::ActiveWindowFocusReason);
-        }
+        if (QWidgetWindow *widgetWindow = qobject_cast<QWidgetWindow *>(wnd))
+            if (QWidget *widget = widgetWindow->widget())
+                if (widget->inherits("QAxHostWidget"))
+                    widget->setFocus(Qt::ActiveWindowFocusReason);
     }
 }
 
diff --git a/src/widgets/kernel/qgesturemanager.cpp b/src/widgets/kernel/qgesturemanager.cpp
index 967ef6b40c..89ed6922b5 100644
--- a/src/widgets/kernel/qgesturemanager.cpp
+++ b/src/widgets/kernel/qgesturemanager.cpp
@@ -545,7 +545,7 @@ bool QGestureManager::filterEvent(QObject *receiver, QEvent *event)
     // filter method.
     QWidgetWindow *widgetWindow = qobject_cast<QWidgetWindow *>(receiver);
 
-    if (widgetWindow)
+    if (widgetWindow && widgetWindow->widget())
         return filterEvent(widgetWindow->widget(), event);
 
     QGesture *state = qobject_cast<QGesture *>(receiver);
diff --git a/src/widgets/kernel/qwidgetwindow.cpp b/src/widgets/kernel/qwidgetwindow.cpp
index b638c6c377..5290d79d9e 100644
--- a/src/widgets/kernel/qwidgetwindow.cpp
+++ b/src/widgets/kernel/qwidgetwindow.cpp
@@ -87,7 +87,7 @@ QRectF QWidgetWindowPrivate::closestAcceptableGeometry(const QRectF &rect) const
 {
     Q_Q(const QWidgetWindow);
     const QWidget *widget = q->widget();
-    if (!widget->isWindow() || !widget->hasHeightForWidth())
+    if (!widget || !widget->isWindow() || !widget->hasHeightForWidth())
         return QRect();
     const QSize oldSize = rect.size().toSize();
     const QSize newSize = QLayout::closestAcceptableSize(widget, oldSize);
@@ -123,7 +123,7 @@ QWidgetWindow::QWidgetWindow(QWidget *widget)
         && !QApplication::testAttribute(Qt::AA_ForceRasterWidgets)) {
         setSurfaceType(QSurface::RasterGLSurface);
     }
-    connect(m_widget, &QObject::objectNameChanged, this, &QWidgetWindow::updateObjectName);
+    connect(widget, &QObject::objectNameChanged, this, &QWidgetWindow::updateObjectName);
     connect(this, SIGNAL(screenChanged(QScreen*)), this, SLOT(handleScreenChange()));
 }
 
@@ -142,16 +142,18 @@ QAccessibleInterface *QWidgetWindow::accessibleRoot() const
 
 QObject *QWidgetWindow::focusObject() const
 {
-    QWidget *widget = m_widget->focusWidget();
+    QWidget *windowWidget = m_widget;
+    if (!windowWidget)
+        return Q_NULLPTR;
+
+    QWidget *widget = windowWidget->focusWidget();
 
     if (!widget)
-        widget = m_widget;
+        widget = windowWidget;
 
-    if (widget) {
-        QObject *focusObj = QWidgetPrivate::get(widget)->focusObject();
-        if (focusObj)
-            return focusObj;
-    }
+    QObject *focusObj = QWidgetPrivate::get(widget)->focusObject();
+    if (focusObj)
+        return focusObj;
 
     return widget;
 }
@@ -174,6 +176,9 @@ static inline bool shouldBePropagatedToWidget(QEvent *event)
 
 bool QWidgetWindow::event(QEvent *event)
 {
+    if (!m_widget)
+        return QWindow::event(event);
+
     if (m_widget->testAttribute(Qt::WA_DontShowOnScreen)) {
         // \a event is uninteresting for QWidgetWindow, the event was probably
         // generated before WA_DontShowOnScreen was set
@@ -201,7 +206,7 @@ bool QWidgetWindow::event(QEvent *event)
 #ifndef QT_NO_ACCESSIBILITY
         QAccessible::State state;
         state.active = true;
-        QAccessibleStateChangeEvent ev(widget(), state);
+        QAccessibleStateChangeEvent ev(m_widget, state);
         QAccessible::updateAccessibility(&ev);
 #endif
         return false; }
@@ -375,7 +380,7 @@ void QWidgetWindow::handleEnterLeaveEvent(QEvent *event)
     } else {
         const QEnterEvent *ee = static_cast<QEnterEvent *>(event);
         QWidget *child = m_widget->childAt(ee->pos());
-        QWidget *receiver = child ? child : m_widget;
+        QWidget *receiver = child ? child : m_widget.data();
         QApplicationPrivate::dispatchEnterLeave(receiver, 0, ee->screenPos());
         qt_last_mouse_receiver = receiver;
     }
diff --git a/src/widgets/kernel/qwidgetwindow_p.h b/src/widgets/kernel/qwidgetwindow_p.h
index ca4bac8d86..7fafb01b3d 100644
--- a/src/widgets/kernel/qwidgetwindow_p.h
+++ b/src/widgets/kernel/qwidgetwindow_p.h
@@ -119,7 +119,7 @@ private:
     };
     QWidget *getFocusWidget(FocusWidgets fw);
 
-    QWidget *m_widget;
+    QPointer<QWidget> m_widget;
     QPointer<QWidget> m_implicit_mouse_grabber;
 #ifndef QT_NO_DRAGANDDROP
     QPointer<QWidget> m_dragTarget;