When entering additional dns search domains linuxconf fails to add the current domain to the list of search domains, such that resolv.conf looks like this: domain: foo.com search: bar.com nameserver 1.2.3.4 With that conifguration in place, the resolver will (either incorrectly or correctly) only search the bar.com domain. this may be a bug in the resolver but one of the two needs to be fixed.
This is not a bug. There may in fact be situations where the local domain should not be searched (for example, the "dsl.[myisp].net" domain). If you leave the search list blank, the default domain is used automatically.
OK, maybe this is a cosmetic / cognitive thing. Probably just my QA experience screaming "This is OK for me, but it's going to cause customer support issues". If I'd thought more about it i could have come to that conclusion, but visually with the fields marked "optional" it looks like they're intended to be additional. I could swear I've used an ip stack that interpreted resolv.conf differently but i can't remember which (os/2 or something)