[ -n "$filename" ] || return 0
config_get servername "$cfg" servername
- [ -n "$servername" ] || return 0
-
config_get serveraddress "$cfg" serveraddress
- [ -n "$serveraddress" ] || return 0
- xappend "--dhcp-boot=${networkid:+net:$networkid,}$filename,$servername,$serveraddress"
+ [ -n "$serveraddress" -a ! -n "$servername" ] && return 0
+
+ xappend "--dhcp-boot=${networkid:+net:$networkid,}${filename}${servername:+,$servername}${serveraddress:+,$serveraddress}"
config_get_bool force "$cfg" force 0