Use "myself" QPointer with "sGui->processEventsToRefreshGui"

Rational: during "sGui->processEventsToRefreshGui" object can be deleted

src/blackgui/guiapplication.cpp

@@ -225,6 +225,7 @@ namespace BlackGui
             if (!m_splashScreen) { return; }
             this->displaySplashMessage(m);
             this->processEventsToRefreshGui();
+            if (!sGui) { return; }
         }
     }
 

src/blackgui/loadindicator.cpp

@@ -51,16 +51,18 @@ namespace BlackGui
         m_angle = 0;
         this->show();
         this->setEnabled(true);
+
+        QPointer<CLoadIndicator> myself(this);
         if (m_timerId == -1) { m_timerId = startTimer(m_delayMs); }
         if (processEvents && sGui)
         {
             sGui->processEventsToRefreshGui();
+            if (!myself) { return -1; } // deleted in meantime (process events)
         }
 
         const int stopId = m_currentId++; // copy
         if (timeoutMs > 0)
         {
-            QPointer<CLoadIndicator> myself(this);
             QTimer::singleShot(timeoutMs, this, [ = ]
             {
                 if (!myself) { return; }

src/swiftguistandard/swiftguistd.cpp

@@ -39,6 +39,7 @@
 #include <Qt>
 #include <QtGlobal>
 #include <QMessageBox>
+#include <QPointer>
 
 class QCloseEvent;
 class QEvent;
@@ -122,8 +123,9 @@ void SwiftGuiStd::performGracefulShutdown()
     ui->comp_MainInfoArea->dockAllWidgets();
 
     // allow some other parts to react
-    if (!sGui) { return; } // overall shutdown
-    sGui->processEventsToRefreshGui();
+    const QPointer<SwiftGuiStd> myself(this);
+    if (sGui) { sGui->processEventsToRefreshGui(); }
+    if (!sGui || !myself) { return; } // killed in meantime?
 
     // tell context GUI is going down
     if (sGui->getIContextApplication())
@@ -132,7 +134,7 @@ void SwiftGuiStd::performGracefulShutdown()
     }
 
     // allow some other parts to react
-    sGui->processEventsToRefreshGui();
+    if (sGui) { sGui->processEventsToRefreshGui(); }
 }
 
 void SwiftGuiStd::closeEvent(QCloseEvent *event)