Re: Bug#523093: undetermined copyright/license violation

[Robert Millan <rmh@aybabtu.com>]

[ Adding Hubert Figuiere (gnote upstream) to CC, note that he's probably not
  subscribed ]

Hi Anthony,

On Wed, Apr 08, 2009 at 09:20:44PM +0100, Anthony W. Youngman wrote:
> In message <[🔎] 20090408194833.GA5615@thorin>, Robert Millan  
> <rmh@aybabtu.com> writes
>>> and a
>>> clear violation of Tomboy's license.
>>
>> Notice license and copyright statements are two separate issues.  AFAIK
>> LGPL doesn't explicitly require that a license notice is preserved mixing
>> code with other licenses like the BSD license does, but I could be mistaken.
>>
>> Any advice on this from -legal?
>
> If it's not your code, and the licence does not give you explicit  
> permission, then you can't change the licence and shouldn't remove the  
> licence note.
>
> Note that the GPLs fall in this category!
>
> The way you "change the licence" with this sort of code is by licencing  
> your code with a compatible licence. The licence for the resulting  
> combined work is the "Venn Intersect" of the two licences. If there's no  
> intersect, then you can't distribute.

Does this apply on a per-file basis?  It seems we have three different
situations:

 a- old file has no copyright/license statement, and a new
    copyright/license statement (for Hubert / GPLv3+) was added.

 b- old file has a copyright/license statement, which is left
    verbatim since the file wasn't modified (or only minimally).

 c- old file has a copyright/license statement, the new file adds
    its own GPLv3+ header and BOTH copyright lines (but not the
    LGPLv2.1 header).

Is any of these at fault?  You're saying that C is incorrect because it
should include both license headers (and not just both copyright lines)?

Is A also at fault because it should say explicitly that the copyright
only covers Hubert's changes (even if noone else bothered to assert their
copyrights)?

> For an example, if a program has three authors, one of whom uses BSD,  
> the second uses "LGPL 2.1 or later" and the third uses "GPL 3" then the  
> Venn Intersect is GPL 3, which is the licence that applies to the work  
> as a whole. However, any recipient is at full liberty to strip out parts  
> of the work, and use whatever licence the author granted.

Yeah, I understand the combined result is GPLv3;  the only doubt I have is
whether it's necessary to explicitly mention each license.

If it's not, is there anything else we should take care of?

Thanks

-- 
Robert Millan

  The DRM opt-in fallacy: "Your data belongs to us. We will decide when (and
  how) you may access your data; but nobody's threatening your freedom: we
  still allow you to remove your data and not access it at all."