[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: GPL "+" question

On Sun, May 31, 2015 at 11:32:57AM +0100, Ian Jackson wrote:
> I think the problem here is the notion that a file necessarily has
> exactly one licence.

Totally agree.


> So it is true that a downstream redistributor who does not change F
> cannot "change the licence", because the only permission needed (in
> copyright law) is that from upstream.  If upstream grant GPLv2+ then
> even if the downstream writes GPLv3+ then everyone can still rely on
> upstream's permission, putting the upstream GPLv2+ notice back.

They can do it because the license never changed, it was *just*
distributed under a different set of terms (the GPLv2+ says you can
distribute it as if it were GPLv3+ and everything is tidy -- it does *not*
say you can yell "hocus pocus" and the license changes into GPLv3+ and
can never be turned back.)

> However, if a downstream redistributor modifies the file, they can
> narrow the set of permissions.  This is because in copyright law, they
> have their own copyright in the modifications.  So if a downstream
> changes GPLv2+ to GPLv3+ _and modifies the file_ then the GPLv2+ is no
> longer applicable.

To the combined / derived work, yes. If the modifications were reverted,
there's no reason the file would be GPLv3+, it'd go back to the original
terms, since you (as *not* the copyright holder) can't relicense the


> (So I think Paul is wrong if he thinks, as he seems to, that it is a
> violation of copyright law to change GPLv2+ to GPLv3+ when merely
> redistributing.)

This is again confusing the issue. Let me be clear:

  A) You can *not* relicense a work that you don't hold.
  B) The GPL*+ grants you the right to redistribute under future terms and
     still be complient with the version that its license under.

You can use B to distribute under the GPLv3 if you would like, but *you
do not relicense the work*. It's still GPLv2.

You can take GPLv2+ and *distribute* it as if it was GPLv3, but you *do
not relicense* the work.

Given that A is a thing, you have no way to do that anyway.

> But to do so would be rude and we should try not to do it.  So I think
> that where practical if we can determine that a package is dual
> (or triple) licenced, we should document all the permissions - that
> is, all the licences.

I think that's sensable, I have a hard time believing upstreams are so
good, honestly, we should be thankful to the author of this package
we're talking about, since they took the time to document it was derived
(hopefully modified!) from a LGPL work.

> It appears that in this particular case package has been modified by
> the GPLv3+-preferring downstream.  In that case there is no permission
> to distribute under GPLv2+ any more.

Totally agree.

> I don't think it is sensible to insist that the Debian maintainer do a
> lot of work to try to discover whether some files in the package have
> /not/ been modified by the GPLv3+-preferring author (or by other
> people who contributed to that author's version and never saw a
> GPLv2+ licence).

I agree we should trust upstream in this case, but I'm generally
interested. I don't like the idea people think they can just magically
relicense files rather then use the right to redistribute.

> That work is not necessary in copyright law, and we aren't really
> doing the Free Software world much of a service by performing it - at
> least, once we have decided to package the GPLv3+ fork at all.
> If someone wants to try to strip the GPLv3+ parts out of the fork
> then that's fine of course, but I don't think we should insist that
> the Debian maintainer do the necessary archaeology.

I don't think that's needed; I love the GPLv3 and I don't see a problem
here :)

I also wouldn't have the maintainer add it to the copyright file, but
there is a lot of misunderstanding on this thread on the mechanism by
which the GPLv3 works.

> > The proof is on you -- where does it say you can relicense someone
> > else's copyrighted work / IP? Not *redistribute*, *relicense*.
> The answer to this question is very clear.  The proof is in the
> original licensing notice:
>   either version 2 of the License, or (at your option) any later
>   version.
> The downstream distributor may choose a later version (3, say, or "any
> version 3 or later) and comply with its terms.

No, wait  Ian :)

Full quote:

| This program is free software; you can redistribute it and/or modify
| it under the terms of the GNU General Public License as published by
| the Free Software Foundation; either version 2 of the License, or
| (at your option) any later version.

You may *redistribute* or *modify*. You may not *relicense*.

I can't come along to gettext and say "it's now GPLv3+", because it will
forever be GPLv2+ until the copyright holder(s) relicense. I can merely
redistribute it under the terms of the GPLv3+, until I modify it, where
I can change the terms of the derived work, but *not* the original

If I revert my changes, there's no reason it'd still be GPLv3+

I strongly think we actually agree, but are poorly expressing it :)


 .''`.  Paul Tagliamonte <paultag@debian.org>  |   Proud Debian Developer
: :'  : 4096R / 8F04 9AD8 2C92 066C 7352  D28A 7B58 5B30 807C 2A87
`. `'`  http://people.debian.org/~paultag
 `-     http://people.debian.org/~paultag/conduct-statement.txt

Attachment: signature.asc
Description: Digital signature

Reply to: