What steps will reproduce the problem?

1. Implement extended selection and IsDragSource on a ListBox

   <ListBox ... SelectionMode="Extended" dd:DragDrop.IsDragSource="True" />

2. Select a least two items on the ListBox

3. On a selected item do a mouse click and release the mouse button.

What is the expected output? What do you see instead? I expect that only one item was selected. Instead of these behavior the selection not change.

If you select all items, then you dont have chance to unselect all items.

The selection must change only on MouseUp, otherwise could not do multiple DragDrop.

What version of the product are you using? On what operating system? - Trunk r17. Windows xp sp3

Please provide any additional information below.

Hello Grokys, here you have a patch for that issue.

Thank you, this is a known problem. I will review your patch shortly!

Sorry it tool so long, but your patch has now been committed to trunk with one small change (m_DragInfo can be null in DragSource_PreviewMouseLeftButtonUp when the user presses Esc to cancel the drag).

Thanks for your patch, this fixes a problem I couldn't work out how to solve, and solves it elegantly.