Appended additional BSD 3-Clause to LICENSE

[oontvoo]

Needed for export_header module

[dmah42]

thanks

[LebedevRI]

This change seems to be missing about 500 words of motivation.

[LebedevRI]

(I would recommend reverting this immediately)

[oontvoo]

This was needed because PR/1321 included code that had this license (the generate_export_header).
This change should have been done there but I guess we didn't have a git license compliant-lint check.

[LebedevRI]

This change should be a lot more explicit about that, it should call out that said new license is only for that single specific file,
otherwise this can be read as if the whole project is now double-licensed. This is a problem.

[dmah42]

why would it be a problem that the project as a whole is double-licensed under these licenses, which are completely compatible?

[LebedevRI]

why would it be a problem that the project as a whole is double-licensed under these licenses, which are completely compatible?

Please consult a lawyer.
Until then, please revert this.

[dmah42]

we have very strong guidance around use of licenses, and specifically double licensed, in third party code at Google and there is no concern with mixing 'notice' style licenses.

in general, the most restrictive license would apply when parts of the code are under separate licenses. note, this applied as soon as the BSD licensed code was added, and this PR is irrelevant as it is just documenting the case. if you want to revert anything, the inclusion of the BSD-licensed code should be reverted.

however, in this case, both licenses are equally restrictive with compatible requirements so there is no issue here.

if you have an issue relating to how you can or can't use a multiply-licensed third party package then we need to look at the use of BSD licensed code, not the documentation of that code.

[LebedevRI]

This change should be a lot more explicit about that, it should call out that said new license is only for that single specific file, otherwise this can be read as if the whole project is now double-licensed. This is a problem.

[oontvoo]

@LebedevRI I've sent PR/1366 . PTAL. Thanks!

[oontvoo]

from my interpretation, LebedevRI's concern is that it's not OK to retrospectively re-license code (which is what this PR sort of accidentally did). I think that's a reasonable point.