Bug#975250: clarify gathering together of copyright information

[Guillem Jover <guillem@debian.org>]

On Thu, 2020-11-26 at 08:55:21 +0000, Holger Levsen wrote:
> AIUI the first year of contributions and the last year of contributions are
> important data points for each contributor for a project, and mostly only
> the last year as that might be used to calculate when a project becomes
> public domain after the dead of an author.

The first year might also be relevant in infringement cases where
provenance might be disputed, but probably less so with a VCS at hand.

> So if I have contributed to something in 2018 and 2020 I find it ok to claim
> 'Copyright 2018-2020 Holger Levsen'.

Personally I see a big distinction between someone doing it for their
own copyright claims, and doing that for someone else's. For example
as was pointed out in the thread, GNU projects tend to do a global
copyright year bump commit at the beginning of the year updating all
the FSF notices, even for things that might otherwise end up not being
changed that year (but which I don't practice as it makes me a bit
uncomfortable).

While I've had no qualms whatsoever on coalescing claimed copyright
years into ranges, for a long time now, even for licenses that state
the copyright notice needs to be preserved (such as BSD), I've always
understood that to preserve the intent of the license, and I've
considered this pretty much accepted practice in the project. But I'd
be very uncomfortable claiming (unclaimed) copyright years on someone
else's behalf (say «© 2008, 20010-2015» into «© 2008-2015»), and
that's something I'd not consider doing.

> (Also because I might not have commited
> something in 2019 but you have no idea how much I prepared my 2020 commits
> in 2019...)

AFAIUI when and what you have done before publication does not count when
it comes to copyright, only the publication date does.

Thanks,
Guillem