[U-Boot-Users] GPL 2 "or later" concern

Andy Green andy at warmcat.com
Tue Sep 19 22:02:50 CEST 2006


Jerry Van Baren wrote:

> If you have source code that is GPLv2 "or later", it is *your* option to 
> exercise the "or later" clause on the source you hold.  If the copyright 
...
> Downstream recipients cannot force *you* to exercise the "or later" 
> clause and force you to GPLv3.  It is their option to convert the source 
> that they hold to GPLv3, but that change flows downstream, not upstream.

Well until the GPL V3 comes out, the "or later" protocol is completely 
untested, since this is the first chance to use it.  Here is a 
hypothetical scenario a few months from now: that a recipient is told by 
the distributor that he may use the given software under V3 terms if he 
likes (this is the "or later" language in the license).  The recipient 
says, "cool, I will modify the software you gave me under V3 terms 
then".  Then the recipient points to section 1 of GPL V3

http://gplv3.fsf.org/gpl-draft-2006-07-27.html

''1. Source Code ... The Corresponding Source also includes any 
encryption or authorization keys necessary to install and/or execute 
modified versions from source code...''

and he says "well then, can I have your signing keys so I can install my 
version?"  The distributor smiles and says, "oh no, I gave you that 
package under GPL v2 terms you see, there is no requirement on me to do 
that".  The recipient says, "I don't know about that, nothing in writing 
about it is there?  But what is in writing, on the license you gave me, 
it says I can 'modify' the code under GPL V2 'or later'.  So I want to 
do that under V3 terms like I said, and you offered in writing.  So your 
keys please!"

I don't know if that would fly or not, but distribution of signed GPL V2 
"or later" code means the signing keys are hostage to the outcome of 
such an attempt, whereas GPL V2-only code is safe from it.

> P.S. I deduce you don't care, but a big part of the consternation over 
> Linus' GPLv2 _only_ stand is because it is impossible to convert the 
> linux kernel to GPLv3 (you would have to get all copyright holders, 
> starting with Linus, to convert their copyrights to GPLv2 "or later" or 
> GPLv3 only).  As a side effect of this, GPLv3 _only_ code will *not* be 
> able to be linked with linux kernel code because GPLv3 puts more 
> restrictions on the code than GPLv2, making it *incompatible* with 
> GPLv2.  Only GPLv2 or GPLv2 "or later" code will be legal in the kernel 
> (and GPLv2 "or later" is frowned on and probably isn't accepted per the 
> stated philosophies of Linus).

Well I would say that I do care about it, but that Linus' stance makes a 
lot of sense to me.  An interesting consideration is that the FSF has a 
monopoly on creating GPL versions, and that if your project uses the "or 
later" language, it can mean you can see your project being distributed 
or modified under terms that you didn't want or ask for, depending on 
what the FSF (ie, RMS) decide to place in the next version which is out 
of your control.  (Admittedly the old rules are still allowed too, so 
that should put a limit on how crazy it can get.)  But only the FSF can 
generate a new version of the GPL which can be applied as an option to 
all existing GPL V2 "or later" projects by magic.

-Andy




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