this drop (copy, move, link, private or ask) as determined by a previous
call to `x-dnd-test-function'. DATA is the drop data.
The function shall return the action used (copy, move, link or private) if drop
this drop (copy, move, link, private or ask) as determined by a previous
call to `x-dnd-test-function'. DATA is the drop data.
The function shall return the action used (copy, move, link or private) if drop