Conflicting medium formats with Discogs possible

[chaban-mb]

It seems Harmony will happily allow mixing digital releases with physical formats when Discogs is involved. There isn't even a warning:
https://harmony.pulsewidth.org.uk/release?url=&gtin=844185002523&region=GB&musicbrainz=&discogs=&deezer=&itunes=&spotify=&tidal=

Permalink:
https://harmony.pulsewidth.org.uk/release?discogs=2388078&spotify=5K6eWqesCPkdNr7iiK2fnf&gtin=844185002523&deezer=&itunes=&tidal=&region=GB&ts=1778405972

It also seems to pick yet another Discogs ID than the already incorrectly linked one on MB:
https://musicbrainz.org/edit/145681638

[kellnerd]

Ah, another scenario which didn't happen before the Discogs provider with the digital-only providers.

Release lookup shows alternative values for medium formats, same as it does for any other potentially conflicting value. Of course there are always users who can't be bothered to check this.
For cases of similar or incorrect medium formats it should not outright cause a merge failure, but I think showing a warning message is a good compromise.

It also seems to pick yet another Discogs ID than the already incorrectly linked one on MB

That's right, the provider currently picks the first result if there are multiple results (nine in this case) for a barcode search. Releases linked to MB don't have any influence on that decision, which is also the case for other providers with multiple results. There is a separate feature request to make a MB lookup trigger additional lookups in #160, another related ticket is #69.

[kellnerd]

P.S. Your example release also revealed an edge case where medium splitting was not working as expected: The MP3 bonus tracks should be on their own medium, not on the 7" Vinyl. Since the Discogs format doesn't mention the files, this will result in the following error message (and Harmony would refuse to merge this with the single medium digital release):

Discogs: Tracklist could not be split into 1 medium as expected, found 2 media