Avoid error message when closing message

dialog with the X field from the WM.


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@30801 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/gtk/msgdlg.cpp

@@ -95,6 +95,11 @@ wxMessageDialog::wxMessageDialog(wxWindow *parent,
                                      GTK_WINDOW(m_parent->m_widget));
 }
  
+wxMessageDialog::~wxMessageDialog()
+{
+    m_widget = NULL;
+}
+
 int wxMessageDialog::ShowModal()
 {
     gint result = gtk_dialog_run(GTK_DIALOG(m_widget));