code review 5669043: net: prefer an IPv4 listen if no address given

net: prefer an IPv4 listen if no address given

This CL avoids net.Listen("tcp", ":80"), http.ListenAdnServe(":80")
prefer an IPv6 listen.

[mikio, 2012-02-14 14:39:21]

Hello rsc@golang.org (cc: golang-dev@googlegroups.com),

I'd like you to review this change to
https://go.googlecode.com/hg/

[rsc, 2012-02-14 15:20:37]

LGTM

Please remind me which systems are broken and don't support IPv4-in-IPv6
mapping?

http://codereview.appspot.com/5669043/diff/4001/src/pkg/net/server_test.go
File src/pkg/net/server_test.go (right):

http://codereview.appspot.com/5669043/diff/4001/src/pkg/net/server_test.go#ne...
src/pkg/net/server_test.go:125: doTest(t, "tcp", "", "127.0.0.1")
Didn't this test just happen above?

[mikio, 2012-02-14 15:41:34]

On Wed, Feb 15, 2012 at 12:20 AM,  <rsc@golang.org> wrote:

> Please remind me which systems are broken and don't support IPv4-in-IPv6
> mapping?

I guess we discussed a few months ago, it's OpenBSD at this moment.
(but it's not broken, intentional)

[mikio, 2012-02-14 15:45:26]

On Wed, Feb 15, 2012 at 12:20 AM,  <rsc@golang.org> wrote:

>
http://codereview.appspot.com/5669043/diff/4001/src/pkg/net/server_test.go#ne...
> src/pkg/net/server_test.go:125: doTest(t, "tcp", "", "127.0.0.1")
> Didn't this test just happen above?

Ah, looks busy.
I'll try to send out a bit clarified test code by this weekend (hope so).

[rsc, 2012-02-14 15:55:23]

On Tue, Feb 14, 2012 at 10:41, Mikio Hara <mikioh.mikioh@gmail.com> wrote:
> I guess we discussed a few months ago, it's OpenBSD at this moment.
> (but it's not broken, intentional)

Thanks.  Could you add a comment in the new code
that it is OpenBSD we're guarding against, just so that
if someone tries to experiment with the code they don't
get confused when it has no effect on non-OpenBSD
systems?

Russ

[mikio, 2012-02-14 15:58:23]

On Wed, Feb 15, 2012 at 12:55 AM, Russ Cox <rsc@golang.org> wrote:

> Thanks.  Could you add a comment in the new code
> that it is OpenBSD we're guarding against, just so that
> if someone tries to experiment with the code they don't
> get confused when it has no effect on non-OpenBSD
> systems?

Sure.

[mikio, 2012-02-14 16:59:21]

*** Submitted as http://code.google.com/p/go/source/detail?r=14bfd680b9d4 ***

net: prefer an IPv4 listen if no address given

This CL avoids net.Listen("tcp", ":80"), http.ListenAdnServe(":80")
prefer an IPv6 listen.

R=rsc
CC=golang-dev
http://codereview.appspot.com/5669043