Apache style issue

[Mark Wielaard]

On Wed, 2009-08-19 at 15:09 -0400, John Cowan wrote: 
> Dag-Erling Smørgrav scripsit:
> 
> > No, it places additional conditions on the licensee's right to
> > distribute.
> 
> I don't see it.  Here's the text:
> 
> # Subject to the terms and conditions of this License, each Contributor
> # hereby grants to You a perpetual, worldwide, non-exclusive, no-charge,
> # royalty-free, irrevocable (except as stated in this section) patent
> # license to make, have made, use, offer to sell, sell, import, and
> # otherwise transfer the Work, where such license applies only to those
> # patent claims licensable by such Contributor that are necessarily
> # infringed by their Contribution(s) alone or by combination of
> # their Contribution(s) with the Work to which such Contribution(s)
> # was submitted. If You institute patent litigation against any entity
> # (including a cross-claim or counterclaim in a lawsuit) alleging that
> # the Work or a Contribution incorporated within the Work constitutes
> # direct or contributory patent infringement, then any patent licenses
> # granted to You under this License for that Work shall terminate as of
> # the date such litigation is filed.
> 
> The first sentence grants You a bunch of licenses to
> necessarily-infringing patents owned by the Contributors.  The second
> sentence limits Your right to sue Contributors for patent infringement
> on pain of losing the license.  Where's the restriction on distribution?

As far as I understand it, it is in the clause after that. The clauses
interact to protect the integrity of the Work as a whole. The
restrictions on redistribution are precisely that you need to retain the
patent grant (and other grant) notices (as formulated in clause 3
above). But if the patent license grant has been revoked, you don't have
permission anymore to transfer the grant of patent license notice to
others, so you cannot obey clause 4 (c) anymore. Effectively making it
impossible to redistribute.