[gentoo-dev] Session/.desktop WM compatibility, DM unification

[Dan Armak]

Hi all,

Many WMs and DEs don't play nice with one another and don't always follow 
freedesktop.org rules. There's a bunch of open bugs (detailed below) and I'm 
sure I've missed some more.

Also, different DMs (kdm, xdm, gdm, ...) have a lot of unique or, conversely, 
duplicated or forked scripts which aren't DM-specific and so should only 
exist once.

I want to work on this, but cooperation between and changes to many WMs are 
required, so I'd like to hear from other people who are interested. These 
bugs all tend to get stuck, so I'm posting this to the list.

Currently a user cannot easily switch WMs or DMs (or use several 
interchangeably) without doing a lot of manual work to carry along settings 
that can and should be neutral. 

(When I say WMs, I sometimes mean entire DEs like KDE/gnome - basically 
whatever gets a session entry in a DM. Gnome can switch its actual WM easily 
enough; that's not my point.)

===== Bugs overview (probably missed some): =====

#89870: long story, summary: .desktop files are installed in different places. 
KDE only reads the KDE ones, Gnome only the Gnome ones (and both use a small 
common set). 

So each DE doesn't benefit from the other's apps (.desktop files aren't just 
for menus but also for e.g. services/actions on mimetypes/etc). 'Lightweight' 
WMs with a menu are forced to choose one of the above to display. (And if you 
merge both, the result is currently very ugly.)

#53517: xdm, kdm, gdm (don't know about entrance and such) each have their own 
set of a lot of configfiles: Xaccess, Xreset, Xservers, Xsession, Xsetup, 
Xstartup, Xwilling... Obviously bad.

Today some files are shared / not duplicated (gdm <-> xdm, kdm <-> xdm), but 
the work is not complete. It seems gdm only has its own Xsession now, and if 
people confirm this I can work on getting rid of all of kdm's separate files 
as well. BUT I still need cooperation here because there might be some 
features in kdm's files which would need to be merged into the common (xdm?) 
ones.

#26326: unifying scripts that run on X sessions startup/shutdown. A lot of 
non-WM-specific stuff, e.g. starting ssh/gpg agents, lives (often duplicated) 
in DM-specific or WM-specific scripts.

#14872: unifying DM session scripts, handling of ~/.xsession, etc. The bug is 
closed but I think some things mentioned there haven't been fixed.

Some other bugs which are assigned to specific teams like KDE would be fixed 
or helped along by a generic solution to the bugs above.

=============

P.S. in some of the cases above, e.g. #89870, some people have said that KDE 
is the real problem because it installs several fdo-like trees (eg 
of .desktop files or of icons), no two of which can coexist, and all of which 
are outside the main tree in /usr. This may be true in some cases, but if the 
latest version of KDE somehow magically appeared in /usr, non-KDE users 
wouldn't be happy either (#89870 again). That's exactly why I want to hear 
others' opinions and what people would like to see.

-- 
Dan Armak
Gentoo Linux developer (KDE)
Public GPG key: http://dev.gentoo.org/~danarmak/danarmak-gpg-public.key
Fingerprint: DD70 DBF9 E3D4 6CB9 2FDD  0069 508D 9143 8D5F 8951