how much right do I have on my project, if there are patches by others?

[Nick Moffitt]

Arnoud Engelfriet:
> Ben Tilly wrote:
> > Bad example.  If you've followed the FSF recommendations for how to
> > apply the GPL (the ones that are written into the GPL), then no
> > permission is needed to go from GPL v2 to v3.
> 
> Those recommendations are not part of the GPL, fortunately.

See the "How to Apply These Terms to Your New Programs" section, which
suggests that you use the wording "either version <N> of the License, or
(at your option) any later version."  These recommendations are not
related to assignment of copyright, and reasonable people differ on the
relative benefits of licensing software in this manner.

-- 
"These people program the way Victorians dress.              Nick Moffitt
It takes two hours and three assistants to put on           nick at zork.net
your clothes, and you have to change before dinner.
But everything is modular."    -- Miles Nordin, on PAM