Re: LGPL-library (tntdb) linked with GPL-library (mysql)

[Don Armstrong <don@debian.org>]

On Sat, 26 Aug 2006, Markus Laire wrote:
> On 8/25/06, Don Armstrong <don@debian.org> wrote:
> >No; the LGPL is always compatible with the GPL. [You can always
> >remove the LGPL from code licensed under it and redistribute it
> >under the GPL.]
> 
> Are you sure? 

Yes. Allow me to quote from the LGPL: 

   3. You may opt to apply the terms of the ordinary GNU General
   Public License instead of this License to a given copy of the
   Library. To do this, you must alter all the notices that refer to
   this License, so that they refer to the ordinary GNU General Public
   License, version 2, instead of to this License. (If a newer version
   than version 2 of the ordinary GNU General Public License has
   appeared, then you can specify that version instead if you wish.)
   Do not make any other change in these notices.

> Because according to your interpretation I would be able to use
> *any* GPL:ed library using the terms of LGPL with this simple trick:

You are misunderstanding my interpretation.

> 1. Take a GPL:ed library
> 2. Create LGPL:ed library which uses the GPL:ed library, and offers
> the exact same functionality.
> 3. Use the created LGPL:ed library instead of the original one, to get
> exact same functionality without (some) restrictions of the GPL.

This requires complying with the GPL because you are creating a
derivative work of the GPLed work.

The LGPL is compatible with the GPL because it can become the GPL. The
reverse is not true, which is what your example is proposing.


Don Armstrong
 
-- 
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 -- Oscar Wilde

http://www.donarmstrong.com              http://rzlab.ucr.edu