I consider this resolved. Some testing will still be done but this 
will be tracked in the corresponding Kolab issue.

Changes have been made in CVS for this ticket:

Fix the file based preferences driver. Only the preferences values 
should get saved (not the mask or the defaults). This changes the file 
format which should be automatically converted once preference data 
with version 1 has been loaded. Bug #8484.
http://cvs.horde.org/diff.php/framework/Prefs/Prefs/file.php?rt=horde&r1=1.1.2.3&r2=1.1.2.4&ty=u

Corresponding bug in the Kolab tracker:



https://issues.kolab.org/issue3555



Thanks for the report as well as the fix.



The suggested line will hotfix the behavior but the actual problem 
lies deeper.



The Prefs/file.php driver completely dumps the preferences information into a

serialized array. That is not exactly what saving preferences is about and all

other drivers only save the preference values actually changed.



I should be able to fix that but this means I'll have to transparently convert

the old file format to the new format.



In the meantime it should be okay to use the hotfix as the format 
conversion should not be affected by it.

Hi,



I forward you a bug reported by a Debian user

(http://bugs.debian.org/538027) :



The file backend of the Prefs subsystem (lib/Horde/Prefs/file.php) dumps

the content to a file as it is represented in memory (cache), including

the dirty flag. This has as a consequence that everything marked dirty

may prevent the user from subsequent changes: if there's another instance

of the Prefs class that's destroying after the instance that made the

changes, the changes will be overwritten with the original content and

seemingly nothing will have changed. I stumbled upon the bug when trying

out the cyrus, imp and kolab: I set up e-mail filters, but after logging

out and again logging in I couldn't add any more filters: they were added

in the GUI, but in fact they weren't written to the disk, which could be

confirmed by a logout/login cycle.

I changed the relevant file (lib/Horde/Prefs/file.php) so, that the

store() function clears dirty flags before writing the content to the

file. This removes the bug.

The relevant patch is:



--- lib/Horde/Prefs/file.php.orig        2008-09-10 12:31:51.000000000 +0200

+++ lib/Horde/Prefs/file.php        2009-07-22 16:56:27.000000000 +0200

@@ -209,6 +209,7 @@

                  }



                  $this->_file_cache[$scope][$name] = $pref;

+                $this->_file_cache[$scope][$name]['m'] &= ~_PREF_DIRTY;

              }

          }