[PTRun] Fix crash when shutting Windows down (#13401)

src/modules/launcher/PowerLauncher/App.xaml.cs

@@ -40,6 +40,9 @@ namespace PowerLauncher
         private StringMatcher _stringMatcher;
         private SettingsReader _settingsReader;
 
+        // To prevent two disposals running at the same time.
+        private static readonly object _disposingLock = new object();
+
         [STAThread]
         public static void Main()
         {
@@ -238,8 +241,22 @@ namespace PowerLauncher
 
         protected virtual void Dispose(bool disposing)
         {
-            if (!_disposed)
+            // Prevent two disposes at the same time.
+            lock (_disposingLock)
             {
+                if (!disposing)
+                {
+                    return;
+                }
+
+                if (_disposed)
+                {
+                    return;
+                }
+
+                _disposed = true;
+            }
+
             Stopwatch.Normal("App.OnExit - Exit cost", () =>
             {
                 Log.Info("Start PowerToys Run Exit----------------------------------------------------  ", GetType());
@@ -256,16 +273,13 @@ namespace PowerLauncher
                     API?.Dispose();
                     _mainVM?.Dispose();
                     _themeManager?.Dispose();
-                        _disposed = true;
                 }
 
                 // TODO: free unmanaged resources (unmanaged objects) and override finalizer
                 // TODO: set large fields to null
-                    _disposed = true;
                 Log.Info("End PowerToys Run Exit ----------------------------------------------------  ", GetType());
             });
         }
-        }
 
         // // TODO: override finalizer only if 'Dispose(bool disposing)' has code to free unmanaged resources
         // ~App()