PlatformSurfaceFilter: fix crash when Scene3D is destroyed after window

When closing a window containing a Scene3D, the aspect engine is
destroyed after the QWindow (because of delete later), so the m_obj
pointer we store inside the PlatformSurfaceFilter becomes dangling,
leading to a crash in the destructor.

Use QPointer to ensure m_obj it set null when it is destroyed.

Fixes: QTBUG-111325
Change-Id: Icf153700a5708abff4b92b14ce2f9bb12d8653eb
Reviewed-by: Paul Lemire <paul.lemire@kdab.com>
(cherry picked from commit 2c3ebe01cb2875bfe48af20446b8c2b62ff49382)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

1 files changed, 2 insertions, 1 deletions

diff --git a/src/render/backend/platformsurfacefilter_p.h b/src/render/backend/platformsurfacefilter_p.h
index 7074850d9..1a4c42c81 100644
--- a/src/render/backend/platformsurfacefilter_p.h
+++ b/src/render/backend/platformsurfacefilter_p.h
@@ -18,6 +18,7 @@
 #include <private/qt3drender_global_p.h>
 
 #include <QtCore/qobject.h>
+#include <QtCore/qpointer.h>
 #include <QtGui/qsurface.h>
 #include <QSemaphore>
 
@@ -64,7 +65,7 @@ public:
         }
     }
 private:
-    QObject *m_obj;
+    QPointer<QObject> m_obj;
     QSurface *m_surface;
 
     static QSemaphore m_surfacesSemaphore;