[Pkg-postgresql-public] Bug#883055: postgresql-contrib-9.6 (re-)installs alternative manpages of postgresql-9.6

[Christoph Berg]

Re: Michael Stapelberg 2017-11-29 <151194305065.23272.18242117195881690843.reportbug at midna.lan>
> The intended state is that only the package which ships the manpage
> (postgresql-9.6 in this case) makes the update-alternatives call.
> 
> Could you please change the postinst script to not make duplicate
> update-alternatives calls? Thank you!

PG 9.6 has just been removed from unstable. For the record,
postgresql-10 should not have this problem, because the contrib
package has been merged into the main server package, so there's
nothing to call twice.

Still, the alternatives handling around PG is pretty involved (we are
still carrying legacy code around for upgrades from 9.1, where some
binary move from one package to another), and I fear the day when the
legacy "postmaster" symlink to "postgres" is going away, which we have
been using as anchor for the alternatives group so far.

Please let us know if there's any more trouble for manpages which we
could fix on the PG side.

Christoph