Re: Implementing reftable in Git

From: Carlos Martín Nieto <cmn@dwim.me>
Date: May 9, 2018, 17:51 UTC
Message-ID: <67fd1816c4da0e54fb88dc29a44b897d41a36602.camel@dwim.me>
In-Reply-To: <20180509164807.GI10348@aiede.svl.corp.google.com>

Hi all,

On Wed, 2018-05-09 at 09:48 -0700, Jonathan Nieder wrote:

Show 28 quoted lines

> Hi,
> 
> Christian Couder wrote:
> 
> > I might start working on implementing reftable in Git soon.
> 
> Yay!
> 
> [...]
> > So I think the most straightforward and compatible way to do it would
> > be to port the JGit implementation.
> 
> I suspect following the spec[1] would be even more compatible, since it
> would force us to tighten the spec where it is unclear.
> 
> >                                        It looks like the
> > JGit repo and the reftable code there are licensed under the Eclipse
> > Distribution License - v 1.0 [7] which is very similar to the 3-Clause
> > BSD License also called Modified BSD License
> 
> If you would like the patches at https://git.eclipse.org/r/q/topic:reftable
> relicensed for Git's use so that you don't need to include that
> license header, let me know.  Separate from any legal concerns, if
> you're doing a straight port, a one-line comment crediting the JGit
> project would still be appreciated, of course.
> 
> That said, I would not be surprised if going straight from the spec is
> easier than porting the code.

Would you expect that this port would keep the Eclipse Distribution License or would it get relicensed to GPLv2?

We would also want to have reftable functionality in the libgit2 project, but it has a slightly different license from git (GPLv2 with linking exception) which requires explicit consent from the authors for us to port over the code from git with its GPLv2 license.

The libgit2 project does have permission from Shawn to relicense his git code, but this would presumably not cover this kind of porting. I don't believe we would have issues if the code remained this BSD-like license.

Sorry for being difficult, but fewer distinct reimplementations is probably a good thing overall.

cc the core libgit2 team

Cheers,
   cmn