[crossfire] Handling of "Created" and "Modified" info in map headers

[Raphaël Quinet]

On Tue, 26 Aug 2008 22:18:33 -0700, Mark Wedel <mwedel at sonic.net> wrote:
> 
>   I think there are several different issues we're talking about.
> 
> If we're talking about giving developers credit, and using the modified field, 
> it may be reasonable to do so.

Yes, that's what I am now talking about: having proper copyright
attributions in the map files.  Knowing the map version and modification
date is also useful, but is less important than respecting copyright IMHO.

>   Note that I don't believe 2a of the license applies in the maps in the context 
> you indicate.  From my reading, 2a covers the case if someone else branches 
> crossfire and makes changes they need to properly record the differences they 
> have modified them and in what way.  I don't read it that the files in the 
> original file have to have that complete change history.

Anyone who modifies any file (such as a map) is producing a modified
version of crossire.  The GPL allows anyone to modify the files and use
them privately without any restrictions.  However, if that code is given
to others (which includes sending the modified version to us), then the
requirements of the GPL apply.  This is explained in the FAQ:
http://www.fsf.org/licensing/licenses/gpl-faq.html#GPLRequireSourcePostedPublic

According to section 2a of the GPLv2, the one who modified the file (and
holds the copyright on the modifications) must then state that the file
was changed and when.  If we accept this modified version and redistribute
it, then section 1 of the GPLv2 requires us to keep intact all copyright
notices.  Again, the GPLv3 explains this more clearly in sections 4 and 5
than the GPLv2 in sections 1 and 2, but the intent is the same.

Note that if someone submits only a small patch, then including it in our
distribution can be considered as "fair use".  In that case, we are not
bound by the license and the requirement to keep the copyright notices.
But for any non-trivial patch, I think that it is clear that we should
keep the copyright notices in the modified files (e.g., in map headers).

The following items in the GPL FAQ are also relevant for the copyright
requirements and "fair use":
http://www.fsf.org/licensing/licenses/gpl-faq.html#RequiredToClaimCopyright
http://www.fsf.org/licensing/licenses/gpl-faq.html#GPLFairUse

With that in mind, I think that it would be more appropriate for map
editors to append "Modified" fields in the map header instead of keeping
only the first one.  Or at least, if the editor doesn't append such a
thing automatically, then it should never remove nor replace existing
"Modified" fields.

Another way to solve this problem would be to use different fields for
different purposes.  We could have an "Id:" field or "Last-Modified:"
field that is automatically updated and may contain $Id$ or $Revision$
for SVN.  And we could have an optional "Modified:" field or maybe
"Copyright:" that is _not_ updated automatically and requires some user
action to decide if their changes are worth a copyright notice.
Requiring some user action (such as selecting "Add modification notice"
or "Add log entry" in some menu of the editor) would avoid the problem
of having too many entries if only minor changes are made.

Again, I am now more worried about respecting copyright than tracking
map versions.  But for the latter, most problems can be solved by having
a separate, automatically updated field for tracking the last revision
number (for those who have SVN access) and/or modification date (for
those who don't have SVN access).

>   And should we even discuss the arch files, we don't have any copyright notice 
> or change notice?  I would almost say those are more problematic as those are 
> more likely to be new work.

Well, there is the top-level CHANGES file, but there is nothing in the
individual files and I agree that archetypes are more problematic.  I
think that most people who contributed archetypes expected them to be
covered by the same license as other parts of crossfire (GPL).

By the way, that CHANGES file should be replaced by a proper ChangeLog
using the standard ChangeLog format.  But that's another topic...

[...]
>   All that said, if some number of Modified: fields were listed, wouldn't bother 
> me that much.  But then if done, I think we might also want to clarify what 
> would be appropriate data there - having a name that one can't associate with 
> anyone in a real basis doesn't add much either.

Well, it doesn't really matter.  It could be some user id, a real name,
an e-mail address, a company name or anything that the copyright holder
considers appropriate for identifying themselves.  So it would be fine for
me to have things like that:
  Created:  1999-12-31 J. Random Hacker
  Modified: 2000-01-01 somebody at example.org
  Modified: 2008-08-27 The Crossfire Development Team
  Modified: 2038-01-19 mwedel
We could also rename all these lines "Copyright:" if we want to make it
clear that they are more useful for copyright tracking than for knowing
the version or modification date of the map.  Although there may be some
value in having separate entries for the original creator and for
subsequent modifications.

-Raphaël