Re: Do I have to release the patch for a GPL software under GPL?

[Alexander Terekhov]

Gordon Burditt wrote:
> 
> >   Now, I, Evil Bill Fence Door, copyright this patch, sell it with
> >   onerous copy protection, and for $1,000,000 a copy.  The license
> >   that comes with it prohibits re-distribution of the patch.  Note
> >   that I'm *not* re-distributing any GPL-licensed software.
> >
> >But you _modified_ a GPL licensed work (section 2 of the GNU GPL), and

Section 2 of the GPL says that a derivative work (under copyright law)
as a whole can be (sub)licensed to third parties under the GPL and only 
the GPL. Not all works "based on" (colloquially) on the GPL'd work are 
derivative works under copyright law. A patch which doesn't contain any 
protected expression from the GPL'd work is NOT a derivative work under 
copyright law. Section 2 of the GPL also says that aggregating GPL
original or derivative work ("a work based on the Program") with 
"another work not based on the Program ... does not bring the other 
work under the scope of this License."

> >now are distributing the modifications to this work.  It is completely
> >irrelevant what the form of the patch is, your patch does not work
> >without the GPLed work, and cannot be used without it so it is a
> >deriviate work.
> 
> Copyright law defines no such thing as a "deriviate work".
> Copyright law and the GPL define a "derivative work", and

The GPL doesn't define derivative works. It explicitly defers to 
(US) copyright law (and hence implicitly to case law interpreting the 
statute) and merely misstates the copyright law in "that is to say" 
wording about "work based on the Program" being "either the Program or 
any derivative work under copyright law". Erroneous misstatements of 
referred statute by the GPL drafter has no bearing on the licensees.

regards,
alexander.