I'd never tried explicitly adding an entry to a folder (e.g. With
Add DVD…), and got a warning dialog when testing that now:
And it's impossible to drag entries into folders. After discovering some entries in collection-less folders I expected to be empty I was wondering how they might have gotten there and if they belonged. Now I understand it's possible those were side effects of a bug you've fixed and not normal/intentional for them to be there, i.e. "Folders can only contain collections" as you said. So, I'll send you the database.pediadata if any entries mysteriously show up in empty folders again.
Thanks for the thanks re: replies. Hopefully a
partial answer to certain questions can be helpful. I'd rather stop before it becomes inaccurate or misleading, deferring to Bruji's more authoritative followup.