Re: FRR package in Debian violates the GPL licence

[Ole Streicher <olebole@debian.org>]

Paul Jakma <paul@jakma.org> writes:
> On Wed, 20 Mar 2019, Ole Streicher wrote:
>
>> This does not match section 1, which allows the distribution of
>> unmodified files along with the proper license information.
>
> What unmodified files are you referring to?

Section 1 handles the case of unmodified files, and this is what I
referred to.

> I have explained several times now that this concerns files which were
> created outside of Quagga [...]
>
> Those files are derived works of the GPL code and must be distributed
> according to the conditions of the GPL licence, if they are to be
> distributed lawfully.

Those files do not use GPL code; they just refer to it. No line of that
code was originated in GPL licensed code.

If someone compiles the code, then the compiler merges the GPL licensed
header, creating an object file that drives from GPL (and must be
distributed as such). But this applies to the object file, not to the
source.

> The GPL licence requires appropriate copyright notices in Section
> 1. Section 1 applies to unmodified files, and it also applies to
> modified files and derived works (see Section 2).

Files written from scratch are not derived works. When I write the
following lines:

#include <log.h>
int main(void) { zlog_rotate(); return 0; }

then this is my own code, not derived from any GPL code. I can
distribute this code under any license I want, even when it is meant to
be used with the Zebra log implementation, and even when it has no
meaning outside of this.

The created *object* file must be under GPL, if zebra's log.h was used
to create it -- since log.h is GPL.

Best

Ole