Comment # 25 on bug 968405 from Egbert Eich

(In reply to Dominique Leuenberger from comment #24)
> (In reply to Egbert Eich from comment #20)
> 
> > > Note: this bug reaches further than XDM - see also the bug I marked as
> > > blockedby.
> > >  Let's not invent solution per package, but let's make standard that work
> > 
> > Dominique, please, let's discuss what we really need for xdm and then see if
> > this applies to other packages as well.
> 
> Egbert, I would change the nature of this bug to what it is: systemd no
> longer honors the documented (on the wiki) way for a package to instruct it
> not to restart a service on update

This could be fixed easily - ie by testing the env variable also before we
source the syconfig/services file. 

However the macros you mentioned in comment #9 (ie the ones from
systemd-rpm-macros) did not play a role in this ticket at all. 
The macros which play a role here are from the rpm package and admittedly
exhibit the same behaviour as the ones from comment #9.

We need to address all of these cases therefore I'm going to include the
maintainer of RPM again.

Besides this - you are talking about 'update' - how do you distinguish 'update'
from 'removal' using the '%pre/%postun' scriptlets?
This may not even matter for the case at hand but since you are looking at the
'general' case, you may have to.