[merb]

I'm not sure something like that is legal:

    - https://github.com/minio/minio/blob/master/pkg/argon2/argon2.go#L38
    - https://github.com/golang/crypto/blob/master/argon2/argon2.go

    > forked from https://golang.org/x/crypto/argon2
    > modified to be used with MinIO under GNU Affero General
    > Public License 3.0 license that can be found in
    > the LICENSE file.

relicense the file based on a small change and also having two licenses on the same file? I'm not so sure, if the go authors are happy about that.

they should probably consult a lawyer...

[yjftsjthsd-h]

Looks like the original is under a permissive ("BSD-style") license, in which case they almost certainly can distribute it under any license they want.

[bsder]

They can distribute it, but this looks like it's changing the license. I thought that only the owner can change the license of the copyrighted file?

Now, you can include BSD-style files with GPL ones without issue--that's true. But I thought you can't change the license of a file from BSD to GPL unless you are the original owner.

[yjftsjthsd-h]

(IANAL) BSD-style licenses generally only require that the file and its derivatives retain the original authors copyright notice. Distributing it under a different license still allows you to fill the original requirements, so there's no conflict there. Or from a different angle, what exactly is the difference between including a BSD file in a GPL file vs including a BSD file in an empty file and then licensing the result as GPL?

Edit: Does it help if I tell you that more precisely they aren't relicensing the file but merely stacking licenses on the file? The process is purely additive.

[sangnoir]

When people say BSD-style licenses are "more permissive" than GPL - this is what they mean. You truly can do whatever you want, as long as you observe the license requirements (i.e. retain the BSD license notice). One can close-source a fork (but keep the notice), or add an additional compatible license like the GPL or AGPL (but keep the BSD notice), or add a license that bars use by cat-lovers (but keep the BSD notice).

> I'm not so sure, if the go authors are happy about that.

Then they should probably switch to a different license - one that more closely mirrors their intent. The cat's out of the bag for all released versions though.