From 2408a4bbbd8db78c890b9911868fb4face7558d7 Mon Sep 17 00:00:00 2001
From: Russ Cox <rsc@golang.org>
Date: Thu, 7 Oct 2010 06:45:50 -0400
Subject: [PATCH] net: allow _ in names

Enables lookup of _jabber._tcp.gmail.com's SRV record.

Fixes #1167.

R=r, r2
CC=golang-dev
https://golang.org/cl/2353043
---
 src/pkg/net/dnsclient.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/pkg/net/dnsclient.go b/src/pkg/net/dnsclient.go
index 0343dd2f0ab..16103c4d05b 100644
--- a/src/pkg/net/dnsclient.go
+++ b/src/pkg/net/dnsclient.go
@@ -207,7 +207,7 @@ func isDomainName(s string) bool {
 		switch {
 		default:
 			return false
-		case 'a' <= c && c <= 'z' || 'A' <= c && c <= 'Z':
+		case 'a' <= c && c <= 'z' || 'A' <= c && c <= 'Z' || c == '_':
 			ok = true
 		case '0' <= c && c <= '9':
 			// fine