Qt: Fix fullscreen

Source/Core/DolphinQt2/Debugger/CodeWidget.cpp

@@ -247,6 +247,9 @@ void CodeWidget::Update()
 
 void CodeWidget::UpdateCallstack()
 {
+  if (Core::GetState() == Core::State::Starting)
+    return;
+
   m_callstack_list->clear();
 
   std::vector<Dolphin_Debugger::CallstackEntry> stack;

Source/Core/DolphinQt2/MainWindow.cpp

@@ -565,7 +565,7 @@ void MainWindow::FullScreen()
   // settings. If it's set to be fullscreen then it just remakes the window,
   // which probably isn't ideal.
   bool was_fullscreen = m_render_widget->isFullScreen();
-  HideRenderWidget();
+  HideRenderWidget(false);
   if (was_fullscreen)
     ShowRenderWidget();
   else
@@ -629,7 +629,7 @@ void MainWindow::ShowRenderWidget()
   {
     // Otherwise, just show it.
     m_rendering_to_main = false;
-    if (SConfig::GetInstance().bFullscreen)
+    if (SConfig::GetInstance().bFullscreen && !m_render_widget->isFullScreen())
     {
       m_render_widget->showFullScreen();
     }
@@ -641,7 +641,7 @@ void MainWindow::ShowRenderWidget()
   }
 }
 
-void MainWindow::HideRenderWidget()
+void MainWindow::HideRenderWidget(bool reinit)
 {
   if (m_rendering_to_main)
   {
@@ -654,12 +654,15 @@ void MainWindow::HideRenderWidget()
     setWindowTitle(QString::fromStdString(Common::scm_rev_str));
   }
 
+  m_render_widget->hide();
+
   // The following code works around a driver bug that would lead to Dolphin crashing when changing
   // graphics backends (e.g. OpenGL to Vulkan). To avoid this the render widget is (safely)
   // recreated
+  if (reinit)
+  {
     disconnect(m_render_widget, &RenderWidget::Closed, this, &MainWindow::ForceStop);
 
-  m_render_widget->hide();
     m_render_widget->removeEventFilter(this);
     m_render_widget->deleteLater();
 
@@ -667,6 +670,7 @@ void MainWindow::HideRenderWidget()
 
     m_render_widget->installEventFilter(this);
     connect(m_render_widget, &RenderWidget::Closed, this, &MainWindow::ForceStop);
+  }
 }
 
 void MainWindow::ShowControllersWindow()

Source/Core/DolphinQt2/MainWindow.h

@@ -100,7 +100,7 @@ private:
   void StartGame(const std::string& path, const std::optional<std::string>& savestate_path = {});
   void StartGame(std::unique_ptr<BootParameters>&& parameters);
   void ShowRenderWidget();
-  void HideRenderWidget();
+  void HideRenderWidget(bool reinit = true);
 
   void ShowSettingsWindow();
   void ShowGeneralWindow();

Source/Core/DolphinQt2/RenderWidget.cpp

@@ -49,6 +49,12 @@ void RenderWidget::HandleCursorTimer()
     setCursor(Qt::BlankCursor);
 }
 
+void RenderWidget::showFullScreen()
+{
+  QWidget::showFullScreen();
+  emit SizeChanged(width(), height());
+}
+
 bool RenderWidget::event(QEvent* event)
 {
   switch (event->type())

Source/Core/DolphinQt2/RenderWidget.h

@@ -17,6 +17,7 @@ public:
   explicit RenderWidget(QWidget* parent = nullptr);
 
   bool event(QEvent* event) override;
+  void showFullScreen();
 
 signals:
   void EscapePressed();