1. Create a ListView or TreeView with multiple selection mode turned on
2. Add a drag listener to the view
3. Select multiple items within the view with the mouse
4. Then click on one of the selected items try to drag all selected items out of the view
Result: The whole selection is erased and only the item you clicked on is part of the drag-selection.
The expected UX behavior would be that the selections stays the same and you can drag all selected items out of the view.