*.localdomain != localhost

*.localdomain != localhost

".localdomain" is not a reserved suffix (or prefix). I'm not aware of any
product expecting *.localdomain to resolve to localhost, however I am aware of
at least one product that defaults to ".localdomain" as its DNS suffix provided
via DHCP (pfSense). This leads to unexpected results when attempting to access
a host that's offline (or a host that's online, when nsswitch.conf is
[mis-]configured to have myhostname ahead of DNS).

Operate on:
localhost (and localhost.)
*.localhost (and *.localhost.)
localhost.localdomain (and localhost.localdomain.)
*.localhost.localdomain (and *.localhost.localdomain.)

We should not cover:
*.localdomain (nor *.localdomain.)
localdomain (nor localdomain.)