[PTRun]Integrated lock mechanism for thread-safe Results updates. (#26104)

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

@@ -605,6 +605,8 @@ namespace PowerLauncher
         }
 
         private void ClearResults()
+        {
+            MainViewModel.PerformSafeAction(() =>
             {
                 _viewModel.Results.SelectedItem = null;
                 System.Threading.Tasks.Task.Run(() =>
@@ -615,6 +617,7 @@ namespace PowerLauncher
                         _viewModel.Results.Results.NotifyChanges();
                     }));
                 });
+            });
         }
 
         private void DeselectAllResults()

src/modules/launcher/PowerLauncher/ViewModel/MainViewModel.cs

@@ -41,7 +41,7 @@ namespace PowerLauncher.ViewModel
         private readonly PowerToysRunSettings _settings;
         private readonly QueryHistory _history;
         private readonly UserSelectedRecord _userSelectedRecord;
-        private readonly object _addResultsLock = new object();
+        private static readonly object _addResultsLock = new object();
         private readonly System.Diagnostics.Stopwatch _hotkeyTimer = new System.Diagnostics.Stopwatch();
 
         private string _queryTextBeforeLeaveResults;
@@ -735,6 +735,8 @@ namespace PowerLauncher.ViewModel
         private void UpdateResultsListViewAfterQuery(string queryText, bool noInitialResults = false, bool isDelayedInvoke = false)
         {
             Application.Current.Dispatcher.BeginInvoke(new Action(() =>
+            {
+                lock (_addResultsLock)
                 {
                     // Using CurrentCultureIgnoreCase since this is user facing
                     if (queryText.Equals(_currentQuery, StringComparison.CurrentCultureIgnoreCase))
@@ -758,6 +760,7 @@ namespace PowerLauncher.ViewModel
                     {
                         Results.Visibility = Visibility.Hidden;
                     }
+                }
             }));
         }
 
@@ -1217,5 +1220,13 @@ namespace PowerLauncher.ViewModel
         {
             return _settings.SearchWaitForSlowResults;
         }
+
+        public static void PerformSafeAction(Action action)
+        {
+            lock (_addResultsLock)
+            {
+                action.Invoke();
+            }
+        }
     }
 }