Question on OSD #5

[Matthew Flaschen]

Chris Travers wrote:
> I.e. if Company C contributed their patented technology willingly to a
> prior version, can they sue Company A for infringement because Company
> A's suit terminated the grant?  Or is does the earlier version's
> license grant patents separately?

First, if company A stops using all versions of the software right
before suing, they're in the clear.  Their license is terminated, but
they're fine as long as they don't use the software any more.

The only question is, can company A keep using the old version (without
company B's patent)?

I think it may depend on the exact details of the patent suit.  If the
suit claimed the whole new program was infringing (including code that
is in both versions), company A might lose access to the old version
too.  If it was careful to say only the new code was infringing, the old
version might still be safe.

>  For example, the
> earlier version's license is separate (and therefore grants a separate
> patent license), which would actually make the GPL v3's retaliation
> clause pretty modest.  I could be wrong though since IANAL.

IANAL either, but I don't think it's minor, because A permanently loses
access to all new code in the new version.  Most of that code will
remain in future versions, making them off-limits too.

>>> So how do we create a patent retaliation
>>> clause which does not allow this sort of abuse?
>> I don't think you can.  I don't think company A would be able sue
>> company B over the Program in any circumstances.  Under GPLv3, A can
>> still sue B over any software patent, for other programs.
> 
> Hmmm..... Rereading....
> 
> Provided that Company A does not agree to the offending version's
> license, I see no reason they couldn't sue.

Sorry, I should have said, they can sue, but then they lose their
license to the Program.

> Under the GPL they might
> be able to do this even if they upgrade but do not distribute the
> software (not sure about this, but it seems that mere use of GPL v3
> software does *not* grant patent licenses).

Only contributing to the Program grants a patent license.  But when you
sue alleging the Program infringes, you lose your GPL license.

Matt Flaschen