Comment # 8 on bug 1021969 from Tony Mechelynck

(In reply to Franck Bui from comment #6)
> (In reply to Tony Mechelynck from comment #4)
> > 
> > You might call this a question of principle: without rebooting, the newly
> > installed systemd (or sysvinit) executable would never be run AFAIK.
> 
> Please have look at the systemctl man page, specially the "daemon-reexec"
> command.

Now I just did. What it doesn't explain is why, after "zypper up -t patch -t
package" finishes installing the upgrade to systemd etc. and the bash prompt
reappears, running "zypper ps" shows the systemd and systemd-journald
executables with the mention "(deleted)". If the daemon had actually reexecuted
itself (and not just done a long branch to its own entry point) the executable
now being run ought to have been the upgraded one, not the old, deleted, one.
So are you sure "systemctl daemon-reexec" is indeed executed as part of the
"zypper up" run?