Reason was a difference in poll functions (dropbox poll function vs.
operator poll function).
So the dropbox was actually recognized as being active (see
`dropbox_active`) but then when actually dropping, the corresponding
operator wasnt called (but instead another operator was).
In detail, the way `wm_handlers_do_intern` works, it checks all
dropboxes poll function if one succeeds it calls the dropbox operator.
But if that operators poll function fails, `wm_handlers_do_intern`
happily continues and "ends" the drop operations in a way we dont
actually get to the "real" dropbox & operator that was also recognized
as being active.
In the case of the report:
- dropbox for `UI_OT_drop_name` is active
- dropbox poll for `NODE_OT_add_object` (`node_object_drop_poll`)
succeeds though
- operator poll for `NODE_OT_add_object` (`node_add_object_poll`) fails
(it checks `UI_but_active_drop_name` already)
So in order to make this work, bring the poll functions in sync by
adding the check for `UI_but_active_drop_name` to two dropbox poll
functions as well.
Probably good for LTS as well.
Philipp Oeser