How to deal with typo "2" instead of "2.1" for "GNU Lesser General Public" in headers?

[David Faure]

On Sunday 04 January 2015 19:03:44 Friedrich W. H. Kossebau wrote:
> Happy New Year, all,
> 
> though I just made a not too happy discovery:
> there are quite some files in the Calligra codebase which have a somehow
> broken license header which names the "GNU Lesser General Public" in
> "version 2 of the License"...
> which does not exist, there is only 2.1 as minimum version (2 was the
> version of the "Library" variant).
> 
> Seems someone once adapted the header from "GNU Library General Public" to
> "GNU Lesser General Public" but forgot the license number

Oops. You know what? This might very well have been me.

I remember hearing about the license name change, and applying it to the new 
files I was writing, and I didn't know that it came with a version number 
increase as well. In fact even now I wouldn't really have been sure about the 
fact that Library=2 and Lesser=2.1.

> , and then people
> happily copied that header over since ages without noticing. Only a few
> files have a correct "GNU Lesser General Public" header.
> 
> Question:
> can it be assumed (and should we) that all contributors actually agreed to
> the "2.1" version of the "Lesser" given there is no "2" version?

Technically I'm not sure, e.g. I thought this was version 2 renamed.
However I never heard of someone agreeing with LGPL v2 and disagreeing with 
v2.1. And your next paragraph is an even bigger reason for going ahead:

> Especially as at least all files I checked also contain "or (at your option)
> any later version.", where "2.1" would be a theoretical later version of
> "2"?

Well, in that case that's even explicitly allowed, then.

> To be on the really safe side I guess one would need to get all contributors
> explicitely agree to the correct version. But pragmatically I would just
> assume people very much were in agreement with 2.1, and this can be
> considered just a typo.
> 
> So would anyone strongly advise against simply applying a patch to all those
> license headers and change the "2" to "2.1"?

Being pragmatic, I would say yes. I really can't see a KDE contributor coming 
back and saying "I wanted my code to be 2 only, not 2.1", given that the only 
relevant difference between these two seems to be the license naming 
(according to wikipedia; I didn't do a diff ;).

-- 
David Faure, faure at kde.org, http://www.davidfaure.fr
Working on KDE Frameworks 5