Bug#711925: apache2-doc's config file breaks apache itself

[Stefan Fritsch <sf@sfritsch.de>]

Am Mittwoch, 24. Juli 2013, 22:07:02 schrieb Stefan Fritsch:
> This is the problem. You have used --purge-unused (with aptitude)
> or  --purge (with apt-get) while upgrading. Or the respective
> config options have been set in the apt/aptitude configuration
> files. This won't work and we will document that in the release
> notes. It will delete your old configuration (which is in
> apache2.2-common) before the new apache2 with the new configuration
> and the upgrade logic is installed. The aptitude man page clearly
> states the dangers of this option, but unfortunately the apt-get
> man page doesn't.
> 
> The bug in apache2 is that we still treat this situation as an
> upgrade  in the postinst even if there is nothing left of the old
> install. If we can detect it, we should probably treat it as a new
> install instead.

We could also add a check to apache2.2-common's prerm to detect the 
purging during an upgrade and abort, and get that change into wheezy 
in a point release. However, only people who have upgraded to the 
latest version will benefit from that change. And I am not sure that 
this is a good approach in any case.