Drag from tree widget

[wysota]

QDrag::start functions add Qt::CopyAction no matter what suggested drop actions were.

I seem to remember this is a necessity on Windows.

... because in dropMimeData, there is no way that I know of to know what is the drag source.

If you are the one creating the mime data, you can subclass it or provide the data you need in some other way to carry it with the object to the drop site.