[sane-devel] Confrmation about license and distribution

[Olaf Meeuwissen]

Hi Iwao,

Seeing that I am still the self-appointed SANE Project Janitor, I guess
I ought reply.

# I'm leaving the project on 2021-02-16 and I suppose Ralph and Povilas
# will help you after that.  Maybe the long-time project admins, Allan
# and Gerhard, as well.

# Full disclosure for list members: I know Iwao from when I worked on
# iscan and imagescanv3 (aka utsushi) at the office.  BTW, I've never
# called him by his first name until now ... :-o.  Doing so after all
# those years feels real weird.

Anyway, on to you mail.

Nakamura Iwao writes:

> Hello All,
>
> We want to modify backend for Epson (epsonds / epson2) and provide it
> to the customer from our Web site, because recent selling scanner
> models support and some feature correction are required to that
> customer.  In such case, the following understanding about license and
> distribution is correct?
>
> + In our understanding, the license of Epson backend (epsonds /
>   epson2) is GPL v2. Then, we would like to include the following
>   license file to the package.
>
>     https://gitlab.com/sane-project/backends/-/blob/master/COPYING
>
>   Is our understanding correct?

The files that make up these backends (plus those they include) refer to
the following licenses:

  - GPL-2.0
  - GPL-2.0-or-later w/ SANE exception
  - Independent JPEG Group License (sanei_jpeg.h and sanei_jinclude.h,
    not explicitly though)
  - public domain (not really a license)

There are also a few files that unfortunately do not explicitly state
what license they are under.  To the best of my knowledge these are
files written by (past) SANE developers so I would assume they are
either GPL-2.0-or-later w/ SANE exception or public domain.

Given that, I think it is reasonably safe to say that the epson2 and
epsonds backends are GPL-2.0, no later version, no SANE exception.

In your package, both source and binary, you need to include a copy of
the [GPL-2.0][0].

 [0]: https://www.gnu.org/licenses/old-licenses/gpl-2.0.txt

For the JPEG license, you should include our [README.djpeg][1] file in
the source package and state that "this software is based in part on the
work of the Independent JPEG Group" for a binary package.  This is all
documented in that README.jpeg (see "LEGAL ISSUES", "In legalese",
points (1) and (2)).

 [1]: https://gitlab.com/sane-project/backends/-/blob/master/README.djpeg

> + When distributing to that customer, we want to distribute it with
>   the Git patch style (i.e. only modified code, not whole package) as
>   below:
>
>     <Distribution Package>
>         Source Code       only modified portion with Git patch style
>         License file      https://gitlab.com/sane-project/backends/-/blob/master/COPYING
>
>   Is there any problems with the above packaging?

Yes.  The GPL states that you need to make sure that recipients of the
software receive or can get all of the source code.  This is clearly
stated in section 3 of the GPL, from which I quote (emphasis added):

  The source code for a work means the preferred form of the work for
  making modifications to it.  For an executable work, *complete* source
  code means all the source code for all modules it contains, *plus* any
  associated interface definition files, *plus* the scripts used to
  control compilation and installation of the executable.

Please read section 3 carefully.  It has all the information you need
with regard to distributing a modified version.

> Please advise to the above.
>
> In this case, this modification and distribution is only for the
> specific Epson scanner models and environment.  Then, we would like to
> investigate about how feedback this modification to SANE Project in
> the near future.

Great to hear that you're willing to contribute your modifications to
the SANE Project.  But there's no need to wait, now, is there?

Like Steven said, just show us the patch.  Right here on the mailing
list (or via a merge request over at GitLab).  I'm sure there will be
folks to look it over or give it a try.  Wouldn't it be nice to have
your patch reviewed and tested by an extra couple of eyes before you
release your modified package?

# Wishful thinking: Might you be interested in maintaining the epson2
# and epsonds backends?  They're looking for a maintainer.

Hope this helps,
--
Olaf Meeuwissen, LPIC-2            FSF Associate Member since 2004-01-27
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