update resets comp flag

[trapd00r]

I don't know if this is a bug or if I'm doing something wrong, but this happens from time to time. During a beet update the comp flag is reset to 0 and the albumartist is modified so that all of a sudden the individual album tracks gets spread all around my library in individual artist directories. Why is this?

/mnt/music8/+TAGGED/+VA/This Is Goa Trance Anthems 2 (2012)/23 Va - This Is Goa Trance Anthems 2 Part 2 Continuous Mix.mp3
  comp: True -> False
  albumartist: Various Artists -> Va
  genre: Goa -> Psychedelic
/mnt/music8/+TAGGED/+VA/This Is Goa Trance Anthems 4 (2012)/01 Man With No Name - Big Troubles In Out Space (oforia Remix).mp3
  comp: True -> False
  albumartist: Various Artists -> Man With No Name
  genre: Goa -> Psychedelic

[wisp3rwind]

Well, without any context, this will be hard to tell. Did you edit the files using some tool other than beets before the beets update? If so, are you sure that that tool didn't simply reset the comp flag (stored as TCMP in mp3s)?

[trapd00r]

No, the only thing I've done is importing with beets.

[wisp3rwind]

Could there be a media player messing with the tags? The reason I'm suspicious is that the genre tag changes. Looking at the the code, I can't immediately exclude that there's an error with our logic for handling comp and albumartist, but that change of genre would be pretty weird without any other program interfering.

It might helpful to see the output of mutagen-inspect <file> for such a file before and after the beet update.

[trapd00r]

1. No; I'm using mpd and it doesn't alter the files in any way that I'm aware of.
2. Cool, didn't know about the suite of mutagen-* tools. The hard thing would be to know, beforehand, when things will be screwed up though. Guess I'll make a habit of supplying the -p flag to update.

[wisp3rwind]

2. Cool, didn't know about the suite of mutagen-* tools. The hard thing would be to know, beforehand, when things will be screwed up though. Guess I'll make a habit of supplying the -p flag to update.

Yeah, that's certainly inconvenient. When this shows up again, I'd be great if you could provide an example of what kind of tags in the file trigger this issue.