net: LookupIP and LookupHost on empty string use domain name

[gopherbot]

by david@mindcry.org:

What does 'go version' print?
go version devel +ee11f19bc514 Mon Jun 23 18:46:01 2014 +0900 openbsd/amd64

What steps reproduce the problem?
If possible, include a link to a program on play.golang.org.

package main

import (
        "fmt"
        "net"
)

func main() {
        s, err := net.LookupHost("")
        fmt.Printf("%v %v\n", s, err)

        ip, err := net.LookupIP("")
        fmt.Printf("%v %v\n", ip, err)

        mx, err := net.LookupMX("")
        fmt.Printf("%v %v\n", mx, err)
}

What happened?
[2001:470:c049::162 24.247.20.162] <nil>
[2001:470:c049::162 24.247.20.162] <nil>
[] lookup : invalid domain name


What should have happened instead?

All Lookup's should have failed with invalid hostname/domainname

Please provide any additional information below.
OpenBSD fog.mindcry.org 5.5 GENERIC.MP#0 amd64

[ianlancetaylor]

Comment 1:

Labels changed: added repo-main, release-go1.4.

[4a6f656c]

Comment 2:

I highly doubt that this is a Go specific issue - the net package is only calling
C.getaddrinfo via cgo. My guess is that a pure C program will behave in the same manner
(most likely related to the new OpenBSD ASR, combined with your resolv.conf
configuration).

Owner changed to @4a6f656c.

Status changed to WaitingForReply.

[rsc]

Comment 3:

Is that your local IP address, 24.247.20.162?
I think that's semi-standard for putting no host in.
It's the same reason that listening to ":12345" really means "listen to local IP address
on that port".
It's a bit odd but I think it's correct.

[gopherbot]

Comment 4 by david@mindcry.org:

OK.
This can be closed anyhow; it was fixed in OpenBSD.

[4a6f656c]

Comment 5:

This was a bug/change in behaviour in the new OpenBSD ASR that has since been fixed (in
OpenBSD). From a Go perspective things were working as intended.

Status changed to WorkingAsIntended.