[gentoo-dev] Eigen and GPL-2 exception - is a new licence required?

[Marcus D. Hanwell]

There is a template library called Eigen I would like to add to the tree. It 
is a dependency of an application I would like to add shortly. It will also 
end up being a dependency of KDE 4 (for kalzium). My question relates to the 
licence the code is released under.

It is licenced under the GNU GPL, version 2 or later with the following 
exception,

// As a special exception, if other files instantiate templates or use macros
// or inline functions from this file, or you compile this file and link it
// with other works to produce a work based on this file, this file does not
// by itself cause the resulting work to be covered by the GNU General Public
// License. This exception does not invalidate any other reasons why a work
// based on this file might be covered by the GNU General Public License.

Please see http://eigen.tuxfamily.org/ for more details. My question is 
whether this requires a new licence to be added to the tree, listing it under 
GPL-2 and then installing a copy of the modified licence or something I have 
not thought of?

Thanks,

Marcus