Restriction on distribution by Novell?

Ben Tilly btilly at
Thu Sep 28 06:11:54 UTC 2006

On 9/27/06, Russ Nelson <nelson at> wrote:
> For B to be distributable, it must be licensed under the GPL.  However
> the PATCH ITSELF does not have to be licensed under the GPL.  It could
> be a proprietary patch to an open source program.

I believe it is false that B has to be licensed under the GPL, and it
is only sometimes true that the patch itself does not have to be
licensed under the GPL.

Let me take an extreme case.  If I take a file full of source code for
Microsoft Windows and diff it against a file full of source code for
Linux, I think it is clear that A is GPLed, B is (hopefully!) not
GPLed, and the patch falls under both copyrights.  Were I to try to
distribute that patch, Microsoft could sue me for copyright violation
and I think they would win. (*)

In the normal case I think the patch may or may not have to be GPLed.
There is no question in my mind that the process of creating and
distributing the patch triggers copyright law.  However there is a
question of whether creating and distributing the patch is allowed
under copyright law.  If it is allowed then there is no need to accept
the GPL to do that distribution, and I agree that the patch need not
be GPLed.  If it is not allowed then, the fact that it is a patch
notwithstanding, the GPL applies.

I gave a case where distribution obviously isn't allowed by copyright
law.  I hope that (at least under US law) it is fair use to send a 5
line patch so that is allowed.  In between lies a big grey area which
I think even lawyers find murky.


* Yes, I picked an extremely stupid example.  For a more reasonable
example, consider a case where a company releases a derivative of a
proprietary program under the GPL.  The existence of a diff between
the original proprietary program and the GPLed version
notwithstanding, the proprietary original remains proprietary.

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