+my $active_ifaces = ['lo', 'ens18', 'ens'];
+my $proc_net = load('proc_net_dev');
+$proc_net =~ s/eth0/ens18/;
+
+my $wanted = load('base-allow-hotplug');
+
+# parse the config
+r($wanted, $proc_net, $active_ifaces);
+
+$wanted =~ s/allow-hotplug ens18/auto ens18/; # FIXME: hack! rather we need to keep allow-hotplug!
+
+expect $wanted;
+
+# idempotency (save, re-parse, and re-check)
+r(w(), $proc_net, $active_ifaces);
+expect $wanted;
+
+# parse one with both, "auto" and "allow-hotplug"
+my $bad = load('base-auto-allow-hotplug');
+r($bad, $proc_net, $active_ifaces);
+
+# should drop the first occuring one of the conflicting options ("auto" currently)
+expect $wanted;
+
+1;