Add isNoHost function and add "no host" check for Go 1.7.6 on Windows

.travis.yml

@@ -1,6 +1,5 @@
 language: go
 go:
-    - 1.6
     - 1.7
     - 1.8
     - master

resolver_miekg.go

@@ -5,6 +5,7 @@ import (
 	"sync"
 
 	"github.com/miekg/dns"
+	"strings"
 )
 
 // NewMiekgDNSResolver returns new instance of Resolver
@@ -66,7 +67,7 @@ func (r *MiekgDNSResolver) LookupTXT(name string) ([]string, error) {
 	txts := make([]string, 0, len(res.Answer))
 	for _, a := range res.Answer {
 		if r, ok := a.(*dns.TXT); ok {
-			txts = append(txts, r.Txt...)
+			txts = append(txts, strings.Join(r.Txt,""))
 		}
 	}
 	return txts, nil
@@ -91,7 +92,7 @@ func (r *MiekgDNSResolver) LookupTXTStrict(name string) ([]string, error) {
 	txts := make([]string, 0, len(res.Answer))
 	for _, a := range res.Answer {
 		if r, ok := a.(*dns.TXT); ok {
-			txts = append(txts, r.Txt...)
+			txts = append(txts, strings.Join(r.Txt,""))
 		}
 	}
 	return txts, nil
@@ -134,9 +135,10 @@ func matchIP(rrs []dns.RR, matcher IPMatcherFunc) (bool, error) {
 // If any address matches, the mechanism matches
 func (r *MiekgDNSResolver) MatchIP(name string, matcher IPMatcherFunc) (bool, error) {
 	var wg sync.WaitGroup
-	hits := make(chan hit)
+	qTypes := []uint16{dns.TypeA, dns.TypeAAAA}
+	hits := make(chan hit, len(qTypes))
 
-	for _, qType := range []uint16{dns.TypeA, dns.TypeAAAA} {
+	for _, qType := range qTypes {
 		wg.Add(1)
 		go func(qType uint16) {
 			defer wg.Done()
@@ -184,7 +186,7 @@ func (r *MiekgDNSResolver) MatchMX(name string, matcher IPMatcherFunc) (bool, er
 	}
 
 	var wg sync.WaitGroup
-	hits := make(chan hit)
+	hits := make(chan hit, len(res.Answer))
 
 	for _, rr := range res.Answer {
 		mx, ok := rr.(*dns.MX)

resolver_miekg_test.go

@@ -1,10 +1,52 @@
 package spf
 
-import "testing"
+import (
+	"testing"
+
+	"github.com/miekg/dns"
+)
 
 func TestMiekgDNSResolver(t *testing.T) {
 	_, e := NewMiekgDNSResolver("8.8.8.8") // invalid TCP address, no port specified
 	if e == nil {
 		t.Errorf(`want "address 8.8.8.8: missing port in address"`)
 	}
 }
+
+func TestMiekgDNSResolver_LookupTXTStrict_Multiline(t *testing.T) {
+	dns.HandleFunc("multiline.test.", zone(map[uint16][]string{
+		dns.TypeTXT: {
+			`multiline.test. 0 IN TXT "v=spf1 ip4:10.0.0.1 ip4:10.0.0" ".2 -all"`,
+		},
+	}))
+	defer dns.HandleRemove("multiline.test.")
+
+	r, e := testResolver.LookupTXTStrict("multiline.test.")
+
+	if e != nil {
+		t.Fatal(e)
+	}
+
+	if len(r) != 1 {
+		t.Errorf("want 1 got %d", len(r))
+	}
+}
+
+func TestMiekgDNSResolver_LookupTXT_Multiline(t *testing.T) {
+	dns.HandleFunc("multiline.test.", zone(map[uint16][]string{
+		dns.TypeTXT: {
+			`multiline.test. 0 IN TXT "v=spf1 ip4:10.0.0.1 ip4:10.0.0" ".2 -all"`,
+		},
+	}))
+	defer dns.HandleRemove("multiline.test.")
+
+	r, e := testResolver.LookupTXT("multiline.test.")
+
+	if e != nil {
+		t.Fatal(e)
+	}
+
+	if len(r) != 1 {
+		t.Errorf("want 1 got %d", len(r))
+	}
+}

resolver_std.go

@@ -8,10 +8,7 @@ import (
 // DNSResolver implements Resolver using local DNS
 type DNSResolver struct{}
 
-func errDNS(e error) error {
-	if e == nil {
-		return nil
-	}
+func isNoHost(e error) bool {
 	if dnsErr, ok := e.(*net.DNSError); ok {
 		// That is the most reliable way I found to detect Permerror
 		// https://github.com/golang/go/blob/master/src/net/dnsclient.go#L43
@@ -25,8 +22,27 @@ func errDNS(e error) error {
 		//  the mechanism continues as if the server returned no error (RCODE
 		//  0) and zero answer records.
 		if dnsErr.Err == "no such host" {
-			return nil
+			return true
 		}
+		if dnsErr.Err == "dnsquery: DNS name does not exist." {
+			return true
+		}
+		if dnsErr.Err == "dnsquery: DNS record does not exist." {
+			return true
+		}
+		if dnsErr.Err == "dnsquery: No records found for given DNS query." {
+			return true
+		}
+	}
+	return false
+}
+
+func errDNS(e error) error {
+	if e == nil {
+		return nil
+	}
+	if isNoHost(e) {
+		return nil
 	}
 	return ErrDNSTemperror
 }
@@ -36,23 +52,9 @@ func errDNS(e error) error {
 func (r *DNSResolver) LookupTXTStrict(name string) ([]string, error) {
 	txts, err := net.LookupTXT(name)
 
-	if dnsErr, ok := err.(*net.DNSError); ok {
-		// That is the most reliable way I found to detect Permerror
-		// https://github.com/golang/go/blob/master/src/net/dnsclient.go#L43
-		// Upon RCODE 3 return code we should return None result and pretend no
-		//  From RFC7208:
-		//  Several mechanisms rely on information fetched from the DNS.  For
-		//  these DNS queries, except where noted, if the DNS server returns an
-		//  error (RCODE other than 0 or 3) or the query times out, the
-		//  mechanism stops and the topmost check_host() returns "temperror".
-		//  If the server returns "Name Error" (RCODE 3), then evaluation of
-		//  the mechanism continues as if the server returned no error (RCODE
-		//  0) and zero answer records.
-		if dnsErr.Err == "no such host" {
-			return nil, ErrDNSPermerror
-		}
+	if isNoHost(err) {
+		return nil, ErrDNSPermerror
 	}
-
 	err = errDNS(err)
 	if err != nil {
 		return nil, err
@@ -117,7 +119,7 @@ func (r *DNSResolver) MatchMX(name string, matcher IPMatcherFunc) (bool, error)
 	}
 
 	var wg sync.WaitGroup
-	hits := make(chan hit)
+	hits := make(chan hit, len(mxs))
 
 	for _, mx := range mxs {
 		wg.Add(1)