data-device: check if there's a source before sending dnd_finish
This could cause a segfault in data_offer_destroy if the offer has version < 3.
Due to an influx of spam, we have had to impose restrictions on new accounts. Please see this wiki page for instructions on how to get full permissions. Sorry for the inconvenience.
This could cause a segfault in data_offer_destroy if the offer has version < 3.