desktop files spec: Plugin based applications and the MimeType key

[Albert Astals Cid]

Some weeks ago i sent a message to xdg list asking for what to do in cases 
like the okular one where you have a plugin based application and depending 
on the installed plugins the supported mimetypes can be different.

The answers where rather small, so it seems it is not something xdg people 
cares a lot, but i do care about it, so i think we should implement a 
solution and then push it to the standard.

See the thread at 
http://lists.freedesktop.org/archives/xdg/2006-September/008556.html

I think the solution listed at 
http://lists.freedesktop.org/archives/xdg/2005-November/007544.html is good 
enough but whitout having to use xml for it as .desktop files are not xml and 
that feels quite strange.

Any objection to adding that kind of thing to KDE4?

Any suggestion before i start hacking on it?

Thanks,
   Albert