Re: Switching GAS to GPLv3

[Nick Clifton <nickc@redhat.com>]

Hi Ralf,

>>> What does this mean for backporting fixes from binutils trunk to older
>>> binutils releases?

>> So the answer appears to be that in order to apply patches made to GPLv3 
>> sources to previous releases we have to change the affected files over 
>> to the GPLv3 as well.
> 
> In my understanding everybody who submits patches to binutils must have
> a copyright assignment to the FSF on file (unless patches are considered
> trivial).

Correct.

> I am I wrong in presuming that a patch contributed under a copyright
> assignment can be implied to cover GPLv2 and GPLv3? 

I think so - I think that there needs to be an explicit statement to this 
effect from the patch's author.

> In other words, if I's submit a patch against a GPLv3'd version of a
> package I'd implicitly assume my patch also to be applicable to a
> GPLv2'd version of the package.

The danger word in that paragraph is "implicit".  My understanding is that 
relicensing the patch needs to be explicit.  Here is what I understand the 
situation to be:

   * If you contribute a patch against a source file which is currently
     licensed under "the GPL version 2 (or at your option a later version)"
     then you, or someone else, may apply that patch to a version of that
     source file that is licensed under version 3 of the GPL.

   * If you contribute a patch against a source file which is currently
     licensed under the GPL version 3, you also have the right to
     explicitly state that your patch can be applied to versions of the
     source file that are licensed under GPLv2 (or indeed any other
     license).  You may choose to make this statement at the time that
     you contribute the patch or at a later date.

   * If however you contribute a patch against a source file which is
     currently licensed under the GPLv3 and you do not make any
     statement about applying the patch to GPLv2 sources then another
     person (or company) cannot take your patch and apply it to the
     GPLv2 copy of the source file without changing the license on that
     file to GPLv3.

     Ie, it is assumed that the person (or company) is backporting the
     patch from the GPLv3 file to the GPLv2 file, rather than receiving
     the patch directly from yourself, and as a consequence the GPLv3
     license is inherited by the patched file.

I hope that this makes things clear.

Cheers
   Nick