Windows: Use QSharedPointer for the dialog helpers.

The dialog thread can outlive the platform dialog helper if
the helper is destroyed. In that case, IFileDialog::Show()
returns since the parent window is destroyed and then tried
to emit signals on the destroyed helper class instance.
Pass a shared pointer to the native dialog instead of a pointer
to the helper class to the dialog.

Task-number: QTBUG-32494
Task-number: QTBUG-30513

Change-Id: I7c2e769460270a26d886fdefee93ea59c2a17196
Reviewed-by: Joerg Bornemann <joerg.bornemann@digia.com>

1 files changed, 4 insertions, 3 deletions

diff --git a/src/plugins/platforms/windows/qwindowsdialoghelpers.h b/src/plugins/platforms/windows/qwindowsdialoghelpers.h
index c0ee60cc1e..1501b02bd9 100644
--- a/src/plugins/platforms/windows/qwindowsdialoghelpers.h
+++ b/src/plugins/platforms/windows/qwindowsdialoghelpers.h
@@ -46,6 +46,7 @@
 #include <qpa/qplatformdialoghelper.h>
 #include <qpa/qplatformtheme.h>
 #include <QtCore/QStringList>
+#include <QtCore/QSharedPointer>
 
 QT_BEGIN_NAMESPACE
 
@@ -64,8 +65,9 @@ namespace QWindowsDialogs
 template <class BaseClass>
 class QWindowsDialogHelperBase : public BaseClass
 {
+    Q_DISABLE_COPY(QWindowsDialogHelperBase)
 public:
-    ~QWindowsDialogHelperBase() { deleteNativeDialog(); }
+    typedef QSharedPointer<QWindowsNativeDialogBase> QWindowsNativeDialogBasePtr;
 
     virtual void exec();
     virtual bool show(Qt::WindowFlags windowFlags,
@@ -79,7 +81,6 @@ protected:
     QWindowsDialogHelperBase();
     QWindowsNativeDialogBase *nativeDialog() const;
     inline bool hasNativeDialog() const { return m_nativeDialog; }
-    void deleteNativeDialog();
     void timerEvent(QTimerEvent *);
 
 private:
@@ -88,7 +89,7 @@ private:
     inline void startDialogThread();
     inline void stopTimer();
 
-    QWindowsNativeDialogBase *m_nativeDialog;
+    QWindowsNativeDialogBasePtr m_nativeDialog;
     HWND m_ownerWindow;
     int m_timerId;
 };