Description of problem:
On every upgrade of this nagios package the init script is deregistered from
chkconfig.

Version-Release number of selected component (if applicable):
nagios-2.0-0.4.rc2.fc4

How reproducible:
Every time

Steps to Reproduce:
1. Install previous version of nagios
2. Upgrade to the current one
  
Actual results:
nagios has been unregistered from chkconfig and therefore will no longer
automatically start on boot.

Expected results:
nagios should still be registered in the same runlevels as before

Additional info:
The problem is the preun script:
  /sbin/service nagios stop > /dev/null 2>&1 || :
  /sbin/chkconfig --del nagios || :

This needs a check for upgrading, as in:
  if [ $1 = 0 ]; then
    /sbin/service nagios stop > /dev/null 2>&1 || :
    /sbin/chkconfig --del nagios || :
  fi

This is a standard idiom in spec files. This would be forgivable in most
packages but nothing emails me to tell me nagios is not running and I only find
out when something else fails quietly. This package really has to get this right
- doesn't anyone review these packages?

As to fixing this: because the preun script is run from the old package this
will break again (for the last time) on the next upgrade. Suggest you warn
people in the email.