From 365ef2fcc34ae3a269dd019b232e3dc9c9550f60 Mon Sep 17 00:00:00 2001
From: Artem Dyomin <artem.dyomin@qt.io>
Date: Wed, 25 Jan 2023 14:39:21 +0100
Subject: Fix random crash with windows backend

It's not clear how to reproduce the crash, but we have crash reports.
The assumption is the crash is a side effect of used deleteLater
for a few objects in the windows backend design. In theory, objects
can have enqueued events that are handled between deleteLater() and
delete, at this time QAudioSink is already deleted.
As a result, I propose using qpointer in order to check
if the object exists.

Task-number: QTBUG-108693
Pick-to: 6.5 6.4
Change-Id: I0c974b1faa6f0a434e95781f22984b532671daa4
Reviewed-by: Lars Knoll <lars@knoll.priv.no>
---
 src/plugins/multimedia/windows/evr/evrcustompresenter_p.h        | 3 ++-
 src/plugins/multimedia/windows/evr/evrd3dpresentengine_p.h       | 3 ++-
 src/plugins/multimedia/windows/player/mfvideorenderercontrol_p.h | 5 +++--
 3 files changed, 7 insertions(+), 4 deletions(-)

(limited to 'src/plugins')

diff --git a/src/plugins/multimedia/windows/evr/evrcustompresenter_p.h b/src/plugins/multimedia/windows/evr/evrcustompresenter_p.h
index 590285be5..5d49c1db9 100644
--- a/src/plugins/multimedia/windows/evr/evrcustompresenter_p.h
+++ b/src/plugins/multimedia/windows/evr/evrcustompresenter_p.h
@@ -22,6 +22,7 @@
 #include <qrect.h>
 #include <qvideoframeformat.h>
 #include <qvideosink.h>
+#include <qpointer.h>
 
 #include <d3d9.h>
 #include <dxva2api.h>
@@ -347,7 +348,7 @@ private:
     IMediaEventSink *m_mediaEventSink; // The EVR's event-sink interface.
     IMFMediaType *m_mediaType; // Output media type
 
-    QVideoSink *m_videoSink;
+    QPointer<QVideoSink> m_videoSink;
     bool m_canRenderToSurface;
     qint64 m_positionOffset; // Seek position in microseconds.
     QRect m_cropRect;  // Video crop rectangle
diff --git a/src/plugins/multimedia/windows/evr/evrd3dpresentengine_p.h b/src/plugins/multimedia/windows/evr/evrd3dpresentengine_p.h
index c9ad5e9c1..b3be7f560 100644
--- a/src/plugins/multimedia/windows/evr/evrd3dpresentengine_p.h
+++ b/src/plugins/multimedia/windows/evr/evrd3dpresentengine_p.h
@@ -19,6 +19,7 @@
 #include <QSize>
 #include <QVideoFrameFormat>
 #include <private/qwindowsiupointer_p.h>
+#include <qpointer.h>
 
 #include <d3d9.h>
 
@@ -130,7 +131,7 @@ private:
 
     QVideoFrameFormat m_surfaceFormat;
 
-    class QVideoSink *m_sink = nullptr;
+    QPointer<QVideoSink> m_sink;
     bool m_useTextureRendering = false;
 #if QT_CONFIG(opengl)
     WglNvDxInterop m_wglNvDxInterop;
diff --git a/src/plugins/multimedia/windows/player/mfvideorenderercontrol_p.h b/src/plugins/multimedia/windows/player/mfvideorenderercontrol_p.h
index 09b7acc2d..3944ba7b6 100644
--- a/src/plugins/multimedia/windows/player/mfvideorenderercontrol_p.h
+++ b/src/plugins/multimedia/windows/player/mfvideorenderercontrol_p.h
@@ -15,7 +15,8 @@
 // We mean it.
 //
 
-#include "qobject.h"
+#include <qobject.h>
+#include <qpointer.h>
 #include <qrect.h>
 #include <mfapi.h>
 #include <mfidl.h>
@@ -48,7 +49,7 @@ private Q_SLOTS:
 private:
     void clear();
 
-    QVideoSink *m_sink = nullptr;
+    QPointer<QVideoSink> m_sink;
     IMFActivate *m_currentActivate = nullptr;
     IMFSampleGrabberSinkCallback *m_callback = nullptr;
 
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