net: LookupAddr("127.0.0.1") is "localhost" not "localhost." on Plan 9 and Windows

This change applies the fix for #13564 to Plan 9 and Windows.
Also enables Lookup API test cases on builders.

Updates #13564.

Change-Id: I863f03c7cb6fbe58b3a55223bfa0ac5f9bf9c3df
Reviewed-on: https://go-review.googlesource.com/18559
Run-TryBot: Mikio Hara <mikioh.mikioh@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

5 files changed, 46 insertions, 53 deletions

diff --git a/src/net/lookup_plan9.go b/src/net/lookup_plan9.go
index 56846bcdbd..a33162882b 100644
--- a/src/net/lookup_plan9.go
+++ b/src/net/lookup_plan9.go
@@ -190,17 +190,6 @@ func lookupPort(network, service string) (port int, err error) {
 	return 0, unknownPortError
 }
 
-// ensureEndDot adds '.' at the end of name unless it is already there.
-func ensureEndDot(name string) string {
-	if name == "" {
-		return "."
-	}
-	if name[len(name)-1] == '.' {
-		return name
-	}
-	return name + "."
-}
-
 func lookupCNAME(name string) (cname string, err error) {
 	lines, err := queryDNS(name, "cname")
 	if err != nil {
@@ -236,8 +225,8 @@ func lookupSRV(service, proto, name string) (cname string, addrs []*SRV, err err
 		if !(portOk && priorityOk && weightOk) {
 			continue
 		}
-		addrs = append(addrs, &SRV{ensureEndDot(f[5]), uint16(port), uint16(priority), uint16(weight)})
-		cname = ensureEndDot(f[0])
+		addrs = append(addrs, &SRV{absDomainName([]byte(f[5])), uint16(port), uint16(priority), uint16(weight)})
+		cname = absDomainName([]byte(f[0]))
 	}
 	byPriorityWeight(addrs).sort()
 	return
@@ -254,7 +243,7 @@ func lookupMX(name string) (mx []*MX, err error) {
 			continue
 		}
 		if pref, _, ok := dtoi(f[2], 0); ok {
-			mx = append(mx, &MX{ensureEndDot(f[3]), uint16(pref)})
+			mx = append(mx, &MX{absDomainName([]byte(f[3])), uint16(pref)})
 		}
 	}
 	byPref(mx).sort()
@@ -271,7 +260,7 @@ func lookupNS(name string) (ns []*NS, err error) {
 		if len(f) < 3 {
 			continue
 		}
-		ns = append(ns, &NS{ensureEndDot(f[2])})
+		ns = append(ns, &NS{absDomainName([]byte(f[2]))})
 	}
 	return
 }
@@ -283,7 +272,7 @@ func lookupTXT(name string) (txt []string, err error) {
 	}
 	for _, line := range lines {
 		if i := byteIndex(line, '\t'); i >= 0 {
-			txt = append(txt, ensureEndDot(line[i+1:]))
+			txt = append(txt, absDomainName([]byte(line[i+1:])))
 		}
 	}
 	return
@@ -303,7 +292,7 @@ func lookupAddr(addr string) (name []string, err error) {
 		if len(f) < 3 {
 			continue
 		}
-		name = append(name, ensureEndDot(f[2]))
+		name = append(name, absDomainName([]byte(f[2])))
 	}
 	return
 }
diff --git a/src/net/lookup_test.go b/src/net/lookup_test.go
index e10be9a210..677a5f57fd 100644
--- a/src/net/lookup_test.go
+++ b/src/net/lookup_test.go
@@ -7,6 +7,7 @@ package net
 import (
 	"bytes"
 	"fmt"
+	"internal/testenv"
 	"runtime"
 	"strings"
 	"testing"
@@ -57,7 +58,7 @@ var lookupGoogleSRVTests = []struct {
 }
 
 func TestLookupGoogleSRV(t *testing.T) {
-	if testing.Short() || !*testExternal {
+	if testing.Short() && testenv.Builder() == "" || !*testExternal {
 		t.Skip("avoid external network")
 	}
 	if !supportsIPv4 || !*testIPv4 {
@@ -91,7 +92,7 @@ var lookupGmailMXTests = []struct {
 }
 
 func TestLookupGmailMX(t *testing.T) {
-	if testing.Short() || !*testExternal {
+	if testing.Short() && testenv.Builder() == "" || !*testExternal {
 		t.Skip("avoid external network")
 	}
 	if !supportsIPv4 || !*testIPv4 {
@@ -122,7 +123,7 @@ var lookupGmailNSTests = []struct {
 }
 
 func TestLookupGmailNS(t *testing.T) {
-	if testing.Short() || !*testExternal {
+	if testing.Short() && testenv.Builder() == "" || !*testExternal {
 		t.Skip("avoid external network")
 	}
 	if !supportsIPv4 || !*testIPv4 {
@@ -153,7 +154,7 @@ var lookupGmailTXTTests = []struct {
 }
 
 func TestLookupGmailTXT(t *testing.T) {
-	if testing.Short() || !*testExternal {
+	if testing.Short() && testenv.Builder() == "" || !*testExternal {
 		t.Skip("avoid external network")
 	}
 	if !supportsIPv4 || !*testIPv4 {
@@ -187,7 +188,7 @@ var lookupGooglePublicDNSAddrTests = []struct {
 }
 
 func TestLookupGooglePublicDNSAddr(t *testing.T) {
-	if testing.Short() || !*testExternal {
+	if testing.Short() && testenv.Builder() == "" || !*testExternal {
 		t.Skip("avoid external network")
 	}
 	if !supportsIPv4 || !supportsIPv6 || !*testIPv4 || !*testIPv6 {
@@ -211,7 +212,7 @@ func TestLookupGooglePublicDNSAddr(t *testing.T) {
 }
 
 func TestLookupIPv6LinkLocalAddr(t *testing.T) {
-	if !supportsIPv6 {
+	if !supportsIPv6 || !*testIPv6 {
 		t.Skip("IPv6 is required")
 	}
 
@@ -242,7 +243,7 @@ var lookupIANACNAMETests = []struct {
 }
 
 func TestLookupIANACNAME(t *testing.T) {
-	if testing.Short() || !*testExternal {
+	if testing.Short() && testenv.Builder() == "" || !*testExternal {
 		t.Skip("avoid external network")
 	}
 	if !supportsIPv4 || !*testIPv4 {
@@ -268,7 +269,7 @@ var lookupGoogleHostTests = []struct {
 }
 
 func TestLookupGoogleHost(t *testing.T) {
-	if testing.Short() || !*testExternal {
+	if testing.Short() && testenv.Builder() == "" || !*testExternal {
 		t.Skip("avoid external network")
 	}
 	if !supportsIPv4 || !*testIPv4 {
@@ -299,7 +300,7 @@ var lookupGoogleIPTests = []struct {
 }
 
 func TestLookupGoogleIP(t *testing.T) {
-	if testing.Short() || !*testExternal {
+	if testing.Short() && testenv.Builder() == "" || !*testExternal {
 		t.Skip("avoid external network")
 	}
 	if !supportsIPv4 || !*testIPv4 {
@@ -421,7 +422,7 @@ func TestLookupIPDeadline(t *testing.T) {
 }
 
 func TestLookupDotsWithLocalSource(t *testing.T) {
-	if !supportsIPv4 {
+	if !supportsIPv4 || !*testIPv4 {
 		t.Skip("IPv4 is required")
 	}
 
@@ -433,7 +434,7 @@ func TestLookupDotsWithLocalSource(t *testing.T) {
 		names, err := LookupAddr("127.0.0.1")
 		fixup()
 		if err != nil {
-			t.Errorf("#%d: %v", i, err)
+			t.Logf("#%d: %v", i, err)
 			continue
 		}
 		mode := "netgo"
@@ -451,8 +452,11 @@ func TestLookupDotsWithLocalSource(t *testing.T) {
 }
 
 func TestLookupDotsWithRemoteSource(t *testing.T) {
-	if testing.Short() || !*testExternal {
-		t.Skipf("skipping external network test")
+	if testing.Short() && testenv.Builder() == "" || !*testExternal {
+		t.Skip("avoid external network")
+	}
+	if !supportsIPv4 || *testIPv4 {
+		t.Skip("IPv4 is required")
 	}
 
 	if fixup := forceGoDNS(); fixup != nil {
diff --git a/src/net/lookup_windows.go b/src/net/lookup_windows.go
index f059d6178b..13edc264e8 100644
--- a/src/net/lookup_windows.go
+++ b/src/net/lookup_windows.go
@@ -213,17 +213,6 @@ func newLookupPort(network, service string) (int, error) {
 	return 0, &DNSError{Err: syscall.EINVAL.Error(), Name: network + "/" + service}
 }
 
-// ensureEndDot adds '.' at the end of name unless it is already there.
-func ensureEndDot(name string) string {
-	if name == "" {
-		return "."
-	}
-	if name[len(name)-1] == '.' {
-		return name
-	}
-	return name + "."
-}
-
 func lookupCNAME(name string) (string, error) {
 	acquireThread()
 	defer releaseThread()
@@ -232,7 +221,7 @@ func lookupCNAME(name string) (string, error) {
 	// windows returns DNS_INFO_NO_RECORDS if there are no CNAME-s
 	if errno, ok := e.(syscall.Errno); ok && errno == syscall.DNS_INFO_NO_RECORDS {
 		// if there are no aliases, the canonical name is the input name
-		return ensureEndDot(name), nil
+		return absDomainName([]byte(name)), nil
 	}
 	if e != nil {
 		return "", &DNSError{Err: os.NewSyscallError("dnsquery", e).Error(), Name: name}
@@ -241,7 +230,7 @@ func lookupCNAME(name string) (string, error) {
 
 	resolved := resolveCNAME(syscall.StringToUTF16Ptr(name), r)
 	cname := syscall.UTF16ToString((*[256]uint16)(unsafe.Pointer(resolved))[:])
-	return ensureEndDot(cname), nil
+	return absDomainName([]byte(cname)), nil
 }
 
 func lookupSRV(service, proto, name string) (string, []*SRV, error) {
@@ -263,10 +252,10 @@ func lookupSRV(service, proto, name string) (string, []*SRV, error) {
 	srvs := make([]*SRV, 0, 10)
 	for _, p := range validRecs(r, syscall.DNS_TYPE_SRV, target) {
 		v := (*syscall.DNSSRVData)(unsafe.Pointer(&p.Data[0]))
-		srvs = append(srvs, &SRV{ensureEndDot(syscall.UTF16ToString((*[256]uint16)(unsafe.Pointer(v.Target))[:])), v.Port, v.Priority, v.Weight})
+		srvs = append(srvs, &SRV{absDomainName([]byte(syscall.UTF16ToString((*[256]uint16)(unsafe.Pointer(v.Target))[:]))), v.Port, v.Priority, v.Weight})
 	}
 	byPriorityWeight(srvs).sort()
-	return ensureEndDot(target), srvs, nil
+	return absDomainName([]byte(target)), srvs, nil
 }
 
 func lookupMX(name string) ([]*MX, error) {
@@ -282,7 +271,7 @@ func lookupMX(name string) ([]*MX, error) {
 	mxs := make([]*MX, 0, 10)
 	for _, p := range validRecs(r, syscall.DNS_TYPE_MX, name) {
 		v := (*syscall.DNSMXData)(unsafe.Pointer(&p.Data[0]))
-		mxs = append(mxs, &MX{ensureEndDot(syscall.UTF16ToString((*[256]uint16)(unsafe.Pointer(v.NameExchange))[:])), v.Preference})
+		mxs = append(mxs, &MX{absDomainName([]byte(syscall.UTF16ToString((*[256]uint16)(unsafe.Pointer(v.NameExchange))[:]))), v.Preference})
 	}
 	byPref(mxs).sort()
 	return mxs, nil
@@ -301,7 +290,7 @@ func lookupNS(name string) ([]*NS, error) {
 	nss := make([]*NS, 0, 10)
 	for _, p := range validRecs(r, syscall.DNS_TYPE_NS, name) {
 		v := (*syscall.DNSPTRData)(unsafe.Pointer(&p.Data[0]))
-		nss = append(nss, &NS{ensureEndDot(syscall.UTF16ToString((*[256]uint16)(unsafe.Pointer(v.Host))[:]))})
+		nss = append(nss, &NS{absDomainName([]byte(syscall.UTF16ToString((*[256]uint16)(unsafe.Pointer(v.Host))[:])))})
 	}
 	return nss, nil
 }
@@ -344,7 +333,7 @@ func lookupAddr(addr string) ([]string, error) {
 	ptrs := make([]string, 0, 10)
 	for _, p := range validRecs(r, syscall.DNS_TYPE_PTR, arpa) {
 		v := (*syscall.DNSPTRData)(unsafe.Pointer(&p.Data[0]))
-		ptrs = append(ptrs, ensureEndDot(syscall.UTF16ToString((*[256]uint16)(unsafe.Pointer(v.Host))[:])))
+		ptrs = append(ptrs, absDomainName([]byte(syscall.UTF16ToString((*[256]uint16)(unsafe.Pointer(v.Host))[:]))))
 	}
 	return ptrs, nil
 }
diff --git a/src/net/lookup_windows_test.go b/src/net/lookup_windows_test.go
index 1a0101196a..7ff32b809b 100644
--- a/src/net/lookup_windows_test.go
+++ b/src/net/lookup_windows_test.go
@@ -177,14 +177,14 @@ func nslookupMX(name string) (mx []*MX, err error) {
 	rx := regexp.MustCompile(`(?m)^([a-z0-9.\-]+)\s+mail exchanger\s*=\s*([0-9]+)\s*([a-z0-9.\-]+)$`)
 	for _, ans := range rx.FindAllStringSubmatch(r, -1) {
 		pref, _, _ := dtoi(ans[2], 0)
-		mx = append(mx, &MX{ensureEndDot(ans[3]), uint16(pref)})
+		mx = append(mx, &MX{absDomainName([]byte(ans[3])), uint16(pref)})
 	}
 	// windows nslookup syntax
 	// gmail.com       MX preference = 30, mail exchanger = alt3.gmail-smtp-in.l.google.com
 	rx = regexp.MustCompile(`(?m)^([a-z0-9.\-]+)\s+MX preference\s*=\s*([0-9]+)\s*,\s*mail exchanger\s*=\s*([a-z0-9.\-]+)$`)
 	for _, ans := range rx.FindAllStringSubmatch(r, -1) {
 		pref, _, _ := dtoi(ans[2], 0)
-		mx = append(mx, &MX{ensureEndDot(ans[3]), uint16(pref)})
+		mx = append(mx, &MX{absDomainName([]byte(ans[3])), uint16(pref)})
 	}
 	return
 }
@@ -198,7 +198,7 @@ func nslookupNS(name string) (ns []*NS, err error) {
 	// golang.org      nameserver = ns1.google.com.
 	rx := regexp.MustCompile(`(?m)^([a-z0-9.\-]+)\s+nameserver\s*=\s*([a-z0-9.\-]+)$`)
 	for _, ans := range rx.FindAllStringSubmatch(r, -1) {
-		ns = append(ns, &NS{ensureEndDot(ans[2])})
+		ns = append(ns, &NS{absDomainName([]byte(ans[2]))})
 	}
 	return
 }
@@ -215,7 +215,7 @@ func nslookupCNAME(name string) (cname string, err error) {
 	for _, ans := range rx.FindAllStringSubmatch(r, -1) {
 		last = ans[2]
 	}
-	return ensureEndDot(last), nil
+	return absDomainName([]byte(last)), nil
 }
 
 func nslookupTXT(name string) (txt []string, err error) {
diff --git a/src/net/non_unix_test.go b/src/net/non_unix_test.go
index b25e0f1daf..db3427e7cb 100644
--- a/src/net/non_unix_test.go
+++ b/src/net/non_unix_test.go
@@ -6,6 +6,17 @@
 
 package net
 
+import "runtime"
+
+// See unix_test.go for what these (don't) do.
+func forceGoDNS() func() {
+	switch runtime.GOOS {
+	case "plan9", "windows":
+		return func() {}
+	default:
+		return nil
+	}
+}
+
 // See unix_test.go for what these (don't) do.
-func forceGoDNS() func()  { return nil }
 func forceCgoDNS() func() { return nil }