Better handling of duplicated torrents/magnets

[drws]

Currently when a torrent/magnet with the same hash as one of the existing ones is added, nothing happens. The user should be informed in such case and ideally even offered to merge useful info from it. For example if a magnet link with only a hash is added and another one with the same hash but also containing a file/folder name is added later on, the missing information could be extracted and used. The same goes for the tracker list. It would be a great feature to be able to quickly merge additional trackers from a later-found torrent or a magnet link instead of throwing the valuable information away.

[LaserEyess]

FWIW, I also think the daemon should help out by detecting and doing something about dupes. But all of the information is present in TRG so we could do something, too.

[drws]

The proposal upstream exists for some time already. Also it appears that Transmission rejects a duplicate with a message, but it seems that it doesn't get through the remote GUI (where nothing happens).