My comment: when adding playlist folders, this may get a bit different since playlist folders may be empty playlists just containing all entries from sub-playlists. So I’ld delay this feature request until playlist folders are available.
After that… I’ld make it an option only, because showing empty playlists can be useful at least for debugging (if the playlist vanishes, is this due to a bug or due to the fact that it’s empty? 😉 ).
Playlist folders are in fact empty playlists with a new dmap flag.
Also, determining if a playlist is empty before serving it is expensive. It means that you have to have the correct playlist count when iTunes enumerates the containerlist. I guess sizes could be updated before a containerlist is pulled.
I dunno. I’m kind of iffy on this. Doing it for static playlists wouldn’t be too bad, but I think doing it for smart playlists would be expensive.
This is a “maybe”, and might not be possible in a manner that is efficient.