Bug#833426: libnss-myhostname breaks exim primary_hostname (#756224)

[Marc Haber]

Package: exim4-base
Version: 4.84.2-2+deb8u1
Severity: important

libnss-myhostname does have an interesting way of interpreting what
gethostbyname is supposed to return. Upstream thinks this behavior is
just fine, see #756224.

Unfortunately, this breaks exim's creation of primary_hostname,
resulting in unqualified addresses getting qualified the wrong way and
ultimately not being delivered. This can lead to loss of mail.

Since the Debian maintainer of libnss-myhostname thinks that packages
that rely on an FQDN actually being an FQDN should conflict with
libnss-myhostname, we should seriously think about adding this
conflict. This will have unfortunate results for the installation base
of libnss-myhostname, sadly.

Greetings
Marc