Re: no need to keep non-copylefted files that way in a copylefted project. (was Re: FRR package in Debian violates the GPL licence)
On 21/03/2019, Christian Kastner <ckk@kvr.at> wrote:
> On 2019-03-20 16:46, Giacomo Tesio wrote:
>> How this relates to compilation?
>
> It doesn't. Nobody is disputing that the compiled result is GPL.
>
> The question at hand is the licensing of the source. These are two
> separate issues.
Sure, I was talking exactly about the licensing of the derived source.
>> If the GPL header at
>> https://github.com/FRRouting/frr/blob/master/lib/command.h is required
>> by https://github.com/FRRouting/frr/blob/master/babeld/babel_interface.c
>
> It's not required. I can download and read the babel_interface.c
> source, which itself is already a copyrightable work, just fine.
>
> The compiler requires *a* command.h to compile babel_interface.c into
> a binary result, but this command.h could theoretically be provided by
> another implementation, licensed under different terms.
Another implementation that uses all of the same texts invented by the
command.h authors and licensed under GPL.
What you say is: I could replace the "Harry Potter and the Sorcerer's
Stone" with another novel under the same name "Harry Potter and the
Sorcerer's Stone" and with the same characters (data structures,
enums...) and places (functions, macros...) AND and a compatible plot
that wouldn't completely change the meaning of the following Rowling's
books WITHOUT complying with Rowling copyright.
I think you are a bit... confused if you think so. :-)
command.h is copyrightable text in itself: it contains macro, data
structures, enums and so on that have been released under GPL.
babel_interface.c is another copyrightable text, but it uses the text
of command.h and could not even exist if command.h didn't existed in
the first place.
Thus babel_interface.c IS a derivative work of command.h: because it
came later and refers heavily to the characters and places provided by
command.h.
babel_interface.c's authors hold the copyright on their own code, but
they received the right to build a derivative work of comand.h's text
under GPL, so they have to abide to the GPL.
Indeed GPLv2 § 2 states:
> These requirements apply to the modified work as a whole.
> IF identifiable SECTIONS of that work ARE NOT DERIVED
> FROM THE PROGRAM, AND CAN BE REASONABLY
> CONSIDERED INDEPENDENT AND SEPARATE WORKS
> IN THEMSELVES, then this License, and its terms, do not
> apply to those sections when you distribute them as separate
> works.
You don't need a programmer to find the text of command.h into
babel_interface.c thus babel_interface cannot be reasonably considered
independent and separate work from command.h.
As such, it can only be distributed under GPLv2.
Q.E.D. ;-)
> Hence why Steve wrote that this amounts to "[...] asserting copyright
> on an interface."
As I said, I'm not sure that asserting copyright on an interface is
something that would hurt free software.
But in this case, this looks as FUD.
Those file are not independent section of FRR, they are derivative of
GPL code and thus distributing them code under a different license is
a violation of GPL terms that cause instant and irrevocable
termination.
Paul might need a court to get this termination enforced.
But you just need to read the license and the code to see the violation.
Giacomo
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