[Run] Crash (`COMException`) when trying drag and drop when other DnD is already in progress

[FWest98]

Microsoft PowerToys version

0.77.0.0

Installation method

GitHub

Running as admin

No

Area(s) with issue?

PowerToys Run

Steps to reproduce

• Start a lengthy drag-n-drop process; for example by extracting a big zip in winrar by dragging the contents to another folder
• Open PT Run, search for a file
• Try to drag-n-drop that file to anywhere

Exception + tracelog:

System.Runtime.InteropServices.COMException: A drag operation is already in progress

   Source: 
   TargetAssembly: WindowsBase, Version=8.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35
   TargetModule: WindowsBase.dll
   TargetSite: Void DoDragDrop(System.Runtime.InteropServices.ComTypes.IDataObject, IOleDropSource, Int32, Int32[])
   at MS.Win32.UnsafeNativeMethods.DoDragDrop(IDataObject dataObject, IOleDropSource dropSource, Int32 allowedEffects, Int32[] finalEffect)
   at System.Windows.OleServicesContext.OleDoDragDrop(IDataObject dataObject, IOleDropSource dropSource, Int32 allowedEffects, Int32[] finalEffect)
   at System.Windows.DragDrop.OleDoDragDrop(DependencyObject dragSource, DataObject dataObject, DragDropEffects allowedEffects)
   at System.Windows.DragDrop.DoDragDrop(DependencyObject dragSource, Object data, DragDropEffects allowedEffects)
   at PowerLauncher.MainWindow.SuggestionsList_MouseMove(Object sender, MouseEventArgs e)
   at System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target)
   at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
   at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args)
   at System.Windows.UIElement.RaiseTrustedEvent(RoutedEventArgs args)
   at System.Windows.Input.InputManager.ProcessStagingArea()
   at System.Windows.Interop.HwndMouseInputProvider.ReportInput(IntPtr hwnd, InputMode mode, Int32 timestamp, RawMouseActions actions, Int32 x, Int32 y, Int32 wheel)
   at System.Windows.Interop.HwndMouseInputProvider.FilterMessage(IntPtr hwnd, WindowMessage msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
   at System.Windows.Interop.HwndSource.InputFilterMessage(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
   at MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
   at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
   at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)

✔️ Expected Behavior

I would expect the drag-drop to work, but I can imagine that might not be possible due to Windows constraints. But then at the very least I would expect PTRun to not crash (or even nicer - show a cross cursor or something to indicate you can't drag-drop)

❌ Actual Behavior

PTRun crashes

Other Software

No response

[willibrandon]

It depends on the internal implementation but normally drag and drop is a synchronous operation on Windows, which would explain why you see this issue with big zips. Windows does have support for asynchronous drag and drop, however, none of the implementations that I’ve seen have included it yet.

This behavior is covered in more detail in Dragging and Dropping Shell Objects Asynchronously.