Subject: Re: When to evaluate dual licenses (was: license categories, was: I'm not supposed to use the ECL v2?)
From: Arnoud Engelfriet <arnoud@engelfriet.net>
Date: Tue, 4 Dec 2007 10:18:14 +0100

Ben Tilly wrote:
> On Dec 3, 2007 2:58 PM, Wilson, Andrew <andrew.wilson@intel.com> wrote:
> > to code as-distributed.  In fact, there are situations where a
> > distributor *must* choose which license applies, and I believe
> > you trigger such a situation in the scenario under discussion
> > (when you want to release modifications to V2-or-later base
> > code under V3, you must choose V3).
> 
> Please quote the section from the GPL v3 that, in your opinion,
> requires someone who is distributing GPL v2 or later code under GPL v3
> to remove the text "GPL v2 or later" and replace it with "GPL v3".

There is, of course, no such text. Why would there be? 
If you elect to distribute a licensed work under the GPLv3 license,
you must indicate that GPLv3 is applicable. It would then be misleading
to leave "GPLv2 or later" in place.

> I'm also having trouble seeing how the distributer is able to stop one
> third party (the copyright holder) from giving permissions to another
> third party (the recipient).  

He isn't, and if the recipient asks for additional permissions from
the copyright holder, that is of course fine too. If I get a GPLv3-only 
work, and I don't want to accept GPLv3, I might write to the copyright 
holder and ask for a different license. 

> I admit to not being a lawyer, but it
> still seems to me to be common sense that the distributer is not part
> of that interaction.  If the copyright holder has said they will not
> sue anyone for using their copyrighted material under the GPL v2 or
> later, then the copyright holder is not going to decide to sue you for
> using it under the GPL v2 just because you happened to get the code
> from someone using the permission grant of the GPL v3.

My view on dual licensing in the case of GPLv{2,3} is that it
depends on whether you explicitly elect either license.

In other words, as long as you can simultaneously satisfy both
GPLv2 and GPLv3 with a particular distribution, it seems to me that
you can distribute under both at the same time. The trivial case is
passing on an unmodified copy of the source code on a CD-ROM.
You then comply with both GPLv2 (section 1) and GPLv3 (section 2).
Your act of distribution can then be interpreted as acceptance
of GPLv2 (section 5) as well as GPLv3 (section 9).  

As long as you don't explicitly elect one version of the GPL,
the recipient is still free to elect either as well.

When you explicitly say "I'm electing GPLv2 only and passing you
a copy under GPLv2 section 1", I don't think the recipient can
automatically exercise GPLv3 on the work. Otherwise you would get
into the absurd situation that the downstream recipient can exercise
a right that the distributor has chosen not to grant him.

For example, suppose the distributor integrates the "GPLv2 or later"
work in a DRM module. Considering section 3 of GPLv3, the distributor
likely only wants to be bound by GPLv2. He could then explicitly
elect GPLv2 only, and comply by identifying GPLv2 and including
source on a CD-ROM with the product.

It would be most peculiar if the recipient could then receive a GPLv3
license to the work from the copyright holder and use its section 3
against the distributor, who explicitly refused to accept GPLv3.

A corner case is what happens when you don't explicitly identify the
license but you perform an act that's only permissible under one
license, I would argue you have implicitly elected that license. For
example, if I distribute a binary using Bittorrent with a README that
says where to get the source, I am in compliance with GPLv3 section
6e but I am violating GPLv2 section 2. I think this proves I have
only elected GPLv3.

You could however also argue that the act of distribution proves
acceptance of GPLv2 (as per section 5) and the distributor just
isn't in compliance. Still, the downstream recipient receives a
GPLv2 license from the copyright holder under GPLv2 section 6.
This section after all doesn't say anything about "if you
distribute _in compliance with this license_" or anything like that.

Arnoud

-- 
Arnoud Engelfriet, Dutch & European patent attorney - Speaking only for myself
Patents, copyright and IPR explained for techies: http://www.iusmentis.com/
              Arnoud blogt nu ook: http://blog.iusmentis.com/