>> Did that join all tracks on one album again? I would expect this to
>> "fix" the database. And thereafter touch some tracks should no longer
>> cause splitting the album.

> I expected this, too - but it didn't. Scanner recognized all (13) tracks
> as scanned but still kept them in 2 different albums as before

Hmm... thinking about this again it might not work indeed: what the
change does is not compare the literal title (because there's often too
much encoding confusion...), but it uses the same "title search" value
we're using in other places, which is kind of a normalized title. But
these are the same now for old and new. Therefore it's possible it
doesn't re-assign, as the album title would match any of the two.

I guess changing the album title of all tracks, rescan, change back,
rescan, would "fix" your database without the need for a full wipe & rescan.

As for the artwork: the artwork ID is based on the artwork file's
timestamp. As for embedded artwork this timestamp is the same as the
music file's timestamp, it did change. And thus triggers new pre-caching
of that artwork. It does not compare the actual file content, only the
file's timestamp.