From a7e30ce9312e8ebfa89194bc899c8afdffa14906 Mon Sep 17 00:00:00 2001
From: Russ Cox <[email protected]>
Date: Tue, 25 Aug 2015 11:25:46 -0400
Subject: [PATCH 14/63] [release-branch.go1.5] net: restore LookupPort for
 integer strings

This worked in Go 1.4 but was lost in the "pure Go" lookup
routines substituted late in the Go 1.5 cycle.

Fixes #12263.

Change-Id: I77ec9d97cd8e67ace99d6ac965e5bc16c151ba83
Reviewed-on: https://go-review.googlesource.com/13915
Reviewed-by: Brad Fitzpatrick <[email protected]>
Reviewed-on: https://go-review.googlesource.com/14243
Reviewed-by: Ian Lance Taylor <[email protected]>
---
 src/net/lookup.go    | 3 +++
 src/net/port_test.go | 2 ++
 2 files changed, 5 insertions(+)

diff --git a/src/net/lookup.go b/src/net/lookup.go
index a7ceee8..9008322 100644
--- a/src/net/lookup.go
+++ b/src/net/lookup.go
@@ -123,6 +123,9 @@ func lookupIPDeadline(host string, deadline time.Time) (addrs []IPAddr, err erro
 
 // LookupPort looks up the port for the given network and service.
 func LookupPort(network, service string) (port int, err error) {
+	if n, i, ok := dtoi(service, 0); ok && i == len(service) {
+		return n, nil
+	}
 	return lookupPort(network, service)
 }
 
diff --git a/src/net/port_test.go b/src/net/port_test.go
index 2dacd97..258a5bd 100644
--- a/src/net/port_test.go
+++ b/src/net/port_test.go
@@ -27,6 +27,7 @@ var portTests = []struct {
 	{"tcp", "time", 37, true},
 	{"tcp", "domain", 53, true},
 	{"tcp", "finger", 79, true},
+	{"tcp", "42", 42, true},
 
 	{"udp", "echo", 7, true},
 	{"udp", "tftp", 69, true},
@@ -36,6 +37,7 @@ var portTests = []struct {
 	{"udp", "ntp", 123, true},
 	{"udp", "snmp", 161, true},
 	{"udp", "syslog", 514, true},
+	{"udp", "42", 42, true},
 
 	{"--badnet--", "zzz", 0, false},
 	{"tcp", "--badport--", 0, false},
-- 
2.6.1