Purging conffiles in stateless packages

[Gioele Barabucci <gioele@svario.it>]

Hello,

is there a guideline on how to treat user-provided configuration files 
during configuration purging in packages for programs that follow the 
"stateless" paradigm (default in `/usr`, override in `/etc`)?

For examples, apticron (the program) has recently switched to a 
stateless configuration. The default configuration is shipped in 
`/usr/lib/apticron/apticron.conf` and the local configuration is written 
by the sysadmin (if they want) in `/etc/apticron.conf`. At the same time 
the maintscript of apticron (the package) says

    purge)
        [...]
        if [ -d /etc/apticron ] ; then
            rm -rf /etc/apticron || true
        fi
        [...]

That means that purging the package will remove also all the 
configuration files provided by the sysadmin. Is this correct?

(I'm asking in the general case, apticron is just an example.)

When there was only one configuration file for both default and 
sysadmin's settings this could had been a sensible way to purge the 
package. With these new stateless packages I'm not so sure that removing 
user-created configuration files makes sense. They are purely 
user-provided data and will never conflict with future 
(re-)installations of the same package.

The policy [1] says nothing explicit on this subject, only

> conffiles and any backup files (~-files, #*# files, %-files, 
.dpkg-{old,new,tmp}, etc.) are removed.

Are there precedents on how to handle the removal of configuration files 
in packages for stateless programs?

Regards,

[1] https://www.debian.org/doc/debian-policy/ch-maintainerscripts.html#id6

--
Gioele Barabucci <gioele@svario.it>