Qt: Avoid stuck in temporary render-to-separate mode

src/duckstation-qt/mainwindow.cpp

@@ -121,6 +121,11 @@ bool QtHost::IsSystemValid()
   return s_system_valid;
 }
 
+bool QtHost::IsFullscreenUIStarted()
+{
+  return s_fullscreen_ui_started;
+}
+
 const QString& QtHost::GetCurrentGameTitle()
 {
   return s_current_game_title;
@@ -1987,8 +1992,8 @@ bool MainWindow::shouldHideMouseCursor() const
 
 bool MainWindow::shouldHideMainWindow() const
 {
-  return Host::GetBoolSettingValue("Main", "HideMainWindowWhenRunning", false) ||
-         (QtHost::CanRenderToMainWindow() && isRenderingFullscreen()) || QtHost::InNoGUIMode();
+  return Host::GetBoolSettingValue("Main", "HideMainWindowWhenRunning", false) || QtHost::CanRenderToMainWindow() ||
+         QtHost::InNoGUIMode();
 }
 
 void MainWindow::switchToGameListView()
@@ -2616,7 +2621,8 @@ bool MainWindow::requestShutdown(bool allow_confirm /* = true */, bool allow_sav
     save_state = save_cb->isChecked();
 
     // Don't switch back to fullscreen when we're shutting down anyway.
-    lock.cancelResume();
+    if (!QtHost::IsFullscreenUIStarted())
+      lock.cancelResume();
   }
 
   // This is a little bit annoying. Qt will close everything down if we don't have at least one window visible,

src/duckstation-qt/qthost.cpp

@@ -1166,7 +1166,7 @@ void EmuThread::confirmActionIfMemoryCardBusy(const QString& action, bool cancel
                                 "seconds for it to finish saving.\n\nDo you want to %1 anyway?")
                                .arg(action)) != QMessageBox::No);
 
-    if (cancel_resume_on_accept)
+    if (cancel_resume_on_accept && !QtHost::IsFullscreenUIStarted())
       lock.cancelResume();
 
     Host::RunOnCPUThread([result, callback = std::move(callback)]() { callback(result); });

src/duckstation-qt/qthost.h

@@ -382,6 +382,9 @@ bool ShouldShowDebugOptions();
 bool IsSystemValid();
 bool IsSystemPaused();
 
+/// Returns true if fullscreen UI is requested.
+bool IsFullscreenUIStarted();
+
 /// Returns true if any lock is in place.
 bool IsSystemLocked();