Discogs source saves TITLE tag as lowercase "Title"

I've noticed that when using the Discogs tag source in Mp3tag, the TITLE field is consistently saved as "Title" (lowercase), even though the .src file explicitly uses "TITLE".

Steps to reproduce:

  1. Confirm no lowercase "Title" tag exists in the FLAC file
  2. Modify discogs.src to use "TITLE"
  3. Fetch tags from Discogs
  4. Resulting file contains "Title" tag instead of "TITLE"

Other fields like ARTIST, ALBUM, GENRE are correctly saved in uppercase. Only TITLE is affected.

Mp3tag version: 3.31a, 3.31c
File type: FLAC

Is this a known issue or a bug in the Discogs integration?

See if there is any connection to this case:

Until the bug is fixed, I’ve added this procedure as a custom action in Mp3tag.
After importing tags from Discogs, the action copies the TITLE field to temp_TITLE, removes the original TITLE, copies temp_TITLE back to TITLE, and then deletes temp_TITLE. In my case, I simply run my “convert TITLE to uppercase” action again as part of this custom action, and it resolves the issue for now.

This is now fixed with Mp3tag v3.35-beta.1.