X-KDE-Protocols=...,smb,...

<http://cgit.freedesktop.org/libreoffice/core/commit/?id=673be8e76856c6bc39f448f3374db4ae84258952> 
"add X-KDE-Protocols," first appearing in LO 4.2.0, adds the line
  X-KDE-Protocols=file,http,smb,ftp,webdav

to each of our *.desktop files.

This apparently instructs KDE's Dolphin to pass smb URLs directly to 
soffice, instead of downloading and passing some /var/tmp filepath to 
soffice.  (In the latter case of going via a /var/tmp filepath, Dolphin 
is apparently smart enough to detect if you edit and save that proxy 
document in LO; it then asks you "File Changed - KIOExec: The file 
smb://... has been modified. Do you want to upload the changes?")
Whether LO (on Linux) can access smb URLs depends on a number of factors:

First, either program/libucpgio1lo.so or program/libucpgvfs1lo.so must 
be installed.
If program/libucpgio1lo.so is installed, LO accesses smb URLs via 
GNOME's GIO framework.  For that GIO framework to successfully handle 
smb URLs, at least on Fedora a package gvfs-smb must be installed.
If program/libucpgvfs1lo.so is installed, LO accesses smb URLs via 
GNOME's deprecated GnomeVFS framework.  For that GnomeVFS framework to 
successfully handle smb URLs, at least on Fedora in a GNOME environment 
a package gnome-vfs2-smb must be installed.  On a Fedora KDE spin, not 
even that appears to suffice, there must be some further magic that's 
missing.
If those requirements are not met, passing an smb URL to soffice 
unhelpfully results in soffice silently doing nothing.
On Fedora, where LO is configured to contain program/libucpgio1lo.so, 
this caused problems on Fedora KDE spins, where the gvfs-smb package is 
not installed by default.  This has been addressed now by making the 
Fedora libreoffice-* packages that contain such *.desktop files require 
gvfs-smb.  (Leaving only the nuisance that, even if a user has entered 
an smb password into Dolphin already, LO asks for the password again.)
Out of curiosity, I wonder how Debian and Ubuntu (where 
673be8e76856c6bc39f448f3374db4ae84258952 originates from) handle 
this.---Björn, Rene?
Hoever, the TDF LO Linux builds are configured to contain 
program/libcupgvfs1lo.so in a libobasis*-gnome-integration package 
(which requires libgnomevfs-2.so.0), while the *.desktop files are in 
packages that have no dependency on the libobasis*-gnome-integration 
package.
So a KDE user installing the TDF LO build without also installing the 
libobasis*-gnome-integration package will have access to files via smb 
silently fail.  (And even installing the libobasis*-gnome-integration 
package does not necessarily change that, see above.)
In light of this, is it helpful that we unconditionally claim smb 
support in those X-KDE-Protocols lines?
(Independently, it would of course be useful if LO failed non-silently 
if it cannot access an smb URL.)
Stephan