How to find a KService which is installed to the xdg_apps dir?

[Cornelius Schumacher]

The configuration dialog in KitchenSync doesn't work anymore, because it 
doesn't find the KResources control module. Its desktop file is installed to 
the xdg_apps dir, but the KCMultiDialog which is used by KitchenSync doesn't 
find it, because it uses KService::serviceByDesktopPath() and this looks 
(according to the API docs) only below "services" and "applnk", not under 
"applications".

What's the correct fix for this problem? Extending the KService::serviceBy*() 
functions to also look up the xdg_apps dir, using another way in 
KCMultiDialog to find the desktop file or something completely different?

-- 
Cornelius Schumacher <schumacher at kde.org>