Lies about most recent backup time

[Stuart Bishop]

Deja-dup cheerfully reports the 'Most recent backup' time for a backup that did not complete has has been removed when a fresh backup job has been restarted.

In my case, my 'Most recent backup' is reported as '4 days ago', hiding the fact from me that on U1 the last completed incremental backup was two months ago and that my scheduled backups have been failing (for reasons that belong in a separate bug).

Ideally, Deja-dup needs to check the actual storage to see if a backup exists, as it may have disappeared due to bugs or reasons beyond its control. It certainly should not be reporting backups as successful when they do not exist. I think to do this, it need to not only check for the existence of a backup, but that it contains the correct number of files.

At a minimum, Deja-dup needs to notice when duplicity has removed an incomplete backup and correct the last-backup time.

[Stuart Bishop (stub)]

It seems that Deja-dup correctly populates the list of restorable backups, so it may be possible to reuse this code to correctly set the 'last backup' text, rather than repeating what Deja-dup believes was the most recent backup.

[Fabian G. (fabiang)]

Also, if manually choosing to finish the backup later, the UI reports time of the latest backup wrong. The time is being updated when the backup is started whilst it should be updated when the backup has successfully finished.