RFH: GPLv3

[Brooks Moses]

Michael Eager wrote:
> Ian Lance Taylor wrote:
>> I believe that we should make a clear statement with that release that
>> any future backport from a later gcc release requires relicensing the
>> changed files to be GPLv3 or later.  I believe this is consistent with
>> the two different licensing requirements, and I believe it is feasible
>> if inconvenient for vendors who distribute patched gcc releases.
> 
> If I understand you, that means that backporting a fix from gcc-4.4
> to gcc-3.4 would suddenly make everything in gcc-3.4 fall under GPLv3.
> 
> I understand that you may be talking about public branches, but
> there are (many) people who are currently using and maintaining
> previous releases.  The same rules would apply equally to private
> backports of patches.
> 
> This would be chaotic.  Acme Co's version of gcc-3.4 might be GPLv2
> while MegaCorp's gcc-3.4 might be GPLv3.

Will, not would.  This is, in practice, not an avoidable hypothetical.

The alternative would be to allow Acme Co to backport patches and leave 
the code GPLv2, and if we do that, someone is going to backport enough 
patches to make a version of gcc-3.4 which is entirely and completely 
identical to gcc-4.4, and claim that they can distribute it as GPLv2.

Even if we were to leave the 4.1 and 4.2 branches open as GPLv2, this 
problem would still happen with things that only got committed to 4.3 
and later.

- Brooks