Re: Mixing GPL and non-copyleft code in source files

[Alexandre Oliva <lxoliva@fsfla.org>]

On Dec 23, 2023, Liliana Marie Prikler <liliana.prikler@gmail.com> wrote:

> the fact remains that
> you want to contribute some work to a project under a different
> license.


> Publishing some source code under the GPL v3
> (or later) does not preclude you as the sole author from also
> publishing it under the CC-0.

... as long as it is understood that "sole author" carries the
implication that it's not a derivative work.

If it is a derivative work, then Wojtek is a licensee who must abide by
the licensors' terms.  GPLv3 §5 seems very clear that the modified work
(as well as the changes that would turn the unmodified program into the
modified work) must be distributed under GPLv3.

Making it available under unauthorized terms could make that
distribution infringing, and integrating that potentially infringing
change seems to be gratuitously inviting trouble.  IANAL, but I'd
strongly recommend against creating such a potential legal mess.

Anything that could be construed as or fall back to a looser license,
from a promise not to enforce the license to using CC0, might plant this
sort of legal landmine on the project, in the worst case, and in the
best case would be effectively equivalent to having the change
published, integrated and distributed under GPLv3+, since after
integration the whole could only be made available like that anyway.


Now, if Wojtek is indeed "sole author" of the changes, then they may
indeed be licensed under any terms of his liking.  But unless the
changes amount to separate programs, integrating them with GNU Guix code
forms a derivative of a GPLv3+ work, which can only be distributed under
GPLv3+.  So even if the changes are made available somewhere under
permissive terms, the version that goes into Guix will be GPLv3.


So, rather than trying to find a different license or invent new
wording, I'd recommend that the version integrated into Guix states that
the license is GPLv3+, which would be factually correct as far as the
project and any downstream recipient is concerned, and at most link to a
copy of the contribution under a more permissive license, *if* the
change is indeed not a derivative work.

Telling whether it is a derivative work is not trivial, though.  A
telling sign that it probably isn't derivative is if the changes could
conceivably have been made without even being in possession or having
ever seen a copy of the unmodified program.  That's not a strict
requirement, but it's a strong hint.

So please proceed with caution.

Thanks,

-- 
Alexandre Oliva, happy hacker                    https://FSFLA.org/blogs/lxo/
   Free Software Activist                           GNU Toolchain Engineer
Disinformation flourishes because many people care deeply about injustice but
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