When importing a backup from a long time ago (more than one DB backup interval ago), a backup would be created the moment the import was done, regardless of when the previous backup was made (so even when that was minutes ago). Now the schedule is kept, by copying over the timestamp of the last DB backup from the current DB to the imported DB.
The changes made since startup, stored in the wal file, were carried over when importing a database. This was because the database file was replaced with the imported database file, but the changes were stored in the wal file. So now we merge all changes into the main database file before replacing them.
