SlaveBase::rename issues

[Jeff Mitchell]

(CCing kde-core-devel as it may be of interest to those out there...)

I'm hitting behavior that I find very undesired in SlaveBase::rename 
while working on a portable media player (pmp:///) kioslave.

Portable devices are identified by (a transformed version of) their 
Solid udi.  These are quite ugly and non-readable, as they are based off 
of (on Linux at least) hal names.  So at a top level, when someone wants 
to see available devices (i.e. enters pmp:/ in Dolphin/Konqui), I 
display a friendly name -- one provided by the library if possible, 
otherwise gleaned from Solid calls, with the Solid udi as a las resort.

To do this the entries listDir returns in pmp:/// have KIO::NAME and 
KIO::URL properties.  So the NAME property is what's shown, and 
double-clicking on it takes it to the device-specific URL as expected.

The problem pops up when I attempt to allow a rename on these devices, 
so that users can set friendly names that will be stored on the device 
(many libraries support this function).  The pseudocode goes like this:

PMPProtocol::rename( src, dest, overwrite)
  //if certain conditions are met such that I know that
  //they are trying to do a top-level rename...
  deviceFor(src)->setFriendlyName( nameFrom( dst ))
  emit finished()
  return

Not emitting finished causes things to go awry, and emitting finished 
causes the displayed name to be modified.

Unfortunately, this doesn't just modify the NAME field but the URL field 
as well.  So when the user then tries to access the device, the URL is 
invalid.

I would contend that if a UDSEntry has both a defined NAME field and a 
defined URL field that, since the user will be attempting to modify the 
displayed name, only the NAME field should be modified.  Modifying the 
URL is totally meaningless in this case.

I can see a few ways to work around this:
1) Fix things so that in the case that a display name is set, a 
modification to that name only affects the display name.
2) Have some way to force a re-listDir() on that directory at the end of 
the rename function (is there a way to do this already that I don't know 
about?)
3) Have some way to choose which fields in a UDSEntry are updated by a 
rename (is there a way to do this already that I don't know about?)

Thanks,
Jeff