Initscript migration to systemd: triggerun called on downgrade

[Petr Pisar]

I'm migrating quota_nld service (provided by quota_nld subpackage of
quota spec) to systemd.

Offical howto <https://fedoraproject.org/wiki/Packaging:ScriptletSnippets#Packages_migrating_to_a_systemd_unit_file_from_a_SysV_initscript> recommends:

%triggerun -- httpd < 1.0-2
# Save the current service runlevel info
[...]

where `httpd < 1.0-2' are httpd packages older then 1.0-2 under
uninstallation and `1.0-2' is first httpd version with systemd support.

I modifed quota accoding this how-to, build a package (everything
locally) and I play with upgrades/downgrades between current F17 version
and this new one.

Everything works except the triggerun script is called even if doing
downgrade. Is it intentional and I do not understand triggers, or is it
a bug in RPM?

-- Petr