Obsoleting configuration files during the upgrade process in debian preinst script

[Erik Wasser <ewasser@maxcluster.de>]

Hello *,

is it possible to modify the function obsolete_conffile_exists() in the
`preinst' script?

I'm asking this with the following background: We're having the
following configuration files in our apache environment:

FILE  /etc/apache2/sites-available/default.conf
DIR   /etc/apache2/sites-available/default
FILES /etc/apache2/sites-available/default/*.conf

During the upgrade process between 2.4.10-10+deb8u4 and 2.4.10-10+deb8u5
'our' directory `/etc/apache2/sites-available/default' was renamed to
`/etc/apache2/sites-available/default.dpkg-remove'.

The restart of the apache then will fail because the configuration file
`/etc/apache2/sites-available/default/default.conf' still referenced to
the moved file/directory
`/etc/apache2/sites-available/default/default.conf'.

My questions are:

1) Is it possible to check against real files with `-f' instead of `-e'
in the `preinst/obsolete_conffile_exists()' function?

2) Is this whole obsolete file check really needed for an upgrade
between two apache 2.4.X instances?

Any thoughts/solutions about this?

-- 
Greetings Erik Wasser