Use NullPaddedInt for R128 tags

[autrimpo]

Fixes issue #2757

[sampsyo]

Thank you! Yes, this seems like exactly the right fix. Would you mind adding a quick summary to the changelog?

[autrimpo]

Sure, I'll add a commit tomorrow.

[sampsyo]

Perfect; thank you! ✨

[djl]

I think this change may have caused beets to write (or rewrite) r128_track_gain and r128_album_gain tags on all of my files. This has made my usual rsync backup a little painful.

I'm going off memory here but I believe beet write -p wanted to change both fields from 0000 -> 0000 which to me looks like nothing should really have changed on the file themselves.

Has anyone else experienced this?

[sampsyo]

Hmm, that's bad news—ideally, the change would only allow the tag to be missing. Perhaps the change is that beets now wants to take the "zero" tags on the files and remove them altogether?

[autrimpo]

It does show 0000 -> 0000 when removing the tags, so I think they only got removed, no other changes should happen. Are you able to check what changes actually occured?

[djl]

Ah! It did indeed remove the tags. Not sure how I missed that.

False alarm then. Sorry for the confusion!

[sampsyo]

No problem! For clarity, maybe it would be a good idea for the UI to display something like "none" instead of "0000" when the value is null (missing).