Re: [Qemu-devel] [PATCH] Mark future contributions to GPLv2-only files as GPLv2+

[Paolo Bonzini]

On 10/21/2011 04:11 PM, Anthony Liguori wrote:
> Otherwise I'm a bit concerned about ambiguity here.  Let's say we have
> to backport a fit to stable, we need to pull in this new copyright
> statement.
>
> But then what if we later discovered we need to pull in a fix from
> before 10/25.  That will appear in the stable tree as a post-10/25
> commit but it carries a GPLv2 only license.

You will never need to include this patch on 0.15 and earlier stable 
branches.

It is legal to take GPLv2+ contributions and restrict them to 
GPLv2-only.  Backporting is distributing, and a distributor can choose 
under which license he does so.  So there should be no problem with 
stable backports, whoever does the backports is implicitly restricting 
the licensing to GPLv2-only.

In fact, the text is just there to inform new contributors of the 
license.  Perhaps just changing the wording satisfies you, like "By 
signing off changes to this files after 10/25 you agree that the file 
may be relicensed under GPLv2+ in the future"?

> I think a per-file flag day is really the only sane approach to this.

We need to make it clear right now that, from now on, GPLv3-incompatible 
changes will not be accepted.

Paolo