hostname - FQDN or not

According to hosts(5), the first word after the IP address in an /etc/hosts entry should be an FQDN.

On the other hand. according to hostname(1), the contents of /etc/hostname on Debian systems should NOT be an FQDN (but just the part before the dot).

However they are both taken from the --hostname parameter of vzctl.

A fix for that would be simple, something like this:

--- a/etc/dists/scripts/debian-set_hostname.sh
+++ b/etc/dists/scripts/debian-set_hostname.sh
@@ -24,7 +24,7 @@ function set_hostname()
        local hostname=$2
 
        [ -z "${hostname}" ] && return 0
- echo "${hostname}" > ${cfgfile}
+ echo "${hostname%%.*}" > ${cfgfile}
        hostname ${hostname}
 }

That strips the domain when creating /etc/hostname.
However this would probably need to be tweaked a little unless the fix for #1035 is reverted. Therefore I'm setting this bug to depend on 1035.

If I'm reading the source correctly, then the only other place that --hostname value is used is vzlist, which should not care much whether it lists a simple hostname or the whole FQDN.

Also, while I'm only speaking for Debian systems, it's possible that other distro's scripts have a similar problem.