pkg: relicense pkg/debian/ as BSD-2-clause

[gperciva]

No description provided.

[cperciva]

Hmm, I think pkg/debian/copyright should include a Tarsnap Backup Inc. copyright line as well?

[cperciva]

(That's a separate issue from this change, I just noticed it when reviewing the diff and we should probably fix it while we're touching that file.)

[gperciva]

Hmm, there's a bunch of cperciva-only copyrights. For example, keygen/tarsnap-keygen.1-mdoc is currently:

.\" Copyright 2007, 2009 Colin Percival

My first instinct is to copy that line and replace your name with "Tarsnap Backup Inc.". But that might be legally murky since the company was incorporated in 2011.

... hmm, the top-level COPYRIGHT has the company copyright starting in 2006.

Anyway, that file received small updates in 2015 and 2016, and a trivial "new sentence, new line" update in 2020.

I see a few options:

1. add the years 2015 and 2016 to your copyright, and a new line for company copyright which has only 2015 and 2016. (And do similar things for all other such files.)
2. add a new copyright date of 2025, and a new line for the company copyright.
3. rely on the top-level COPYRIGHT, and remove file-specific copyright statements unless there's other statements in that file (for example, tar/tree.c).

[cperciva]

Just change them to Tarsnap Backup Inc. The company can hold copyrights which were created before the company existed -- a copyright statement is not an authorship statement.

[gperciva]

Ok. And the dates? tar/tarsnap.1-mdoc.in has had significant changes over the years, but it's noted as 2007-2009.

[cperciva]

Go ahead and update it to 2007 - YYYY for whatever the appropriate year is. (I think 2025?)

[gperciva]

It's rather a mess.

• some people say that the year should only be updated if there's "non-trivial" changes to the file.
• some people say that the year should only be updated when there's a release.
  (I haven't yet found anybody claiming that doing a git push to a repo on github counts as a release, but honestly, my first guess is that it should count as such.)
• some people (including the FSF) say that we can only use a range if every single year in the range is a "copyrightable" year. https://www.gnu.org/licenses/gpl-howto.html#copyright-notice
• also, 99% of software copyright advice online is about US law. I skimmed a few pages from the Canadian government, but didn't see anything about updating the copyright year for software projects. I haven't tried to read the actual statute.

Unfortunately I can't find anything about updating years on https://docs.freebsd.org/en/articles/license-guide/

Based on my non-lawyer understanding, the safest thing is to add a single copyright year (rather than a range) for the last "non-trivial" change to each file. But if you want me to put a range to 2025, I'm quite content to do that.

[cperciva]

Just put in a range. The Berne convention makes copyright statements legally unnecessary anyway; the FSF thing is just their house style.

[cperciva]

FWIW a bunch of copyright statements get bumped in FreeBSD as soon as the new year arrives, often before any substantive commits.