Bug#796884: dh_systemd: should preserve static masks between remove and purge

[Felipe Sateler]

Package: systemd
Severity: normal
Version: 1.23

When a package ships a static mask (a link from
/lib/systemd/system/$service => /dev/null), this mask will be removed
by dpkg on package remove. However, sysv scripts are conffiles so dpkg
doesn't touch them until purge.

Therefore packages that ship a link to mask a sysv unit, when the
package is removed but not purged, go back to the sysv generator for
the service in question. This is particularly bad for runlevel S
services.

dh_systemd_enable should probably create the link on postrm remove,
and remove it on postrm purge. Ideally this dance would only be done
when the mask is for a sysv script; however I expect most masks will
be to hide sysv services so this should not be a major problem in
practice.



-- 

Saludos,
Felipe Sateler