:authority should include port number (#1123)

clientconn.go

@@ -38,7 +38,6 @@ import (
 	"fmt"
 	"math"
 	"net"
-	"strings"
 	"sync"
 	"time"
 
@@ -360,11 +359,7 @@ func DialContext(ctx context.Context, target string, opts ...DialOption) (conn *
 	} else if cc.dopts.insecure && cc.dopts.copts.Authority != "" {
 		cc.authority = cc.dopts.copts.Authority
 	} else {
-		colonPos := strings.LastIndex(target, ":")
-		if colonPos == -1 {
-			colonPos = len(target)
-		}
-		cc.authority = target[:colonPos]
+		cc.authority = target
 	}
 	waitC := make(chan error, 1)
 	go func() {

clientconn_test.go

@@ -69,6 +69,18 @@ func TestTLSDialTimeout(t *testing.T) {
 	}
 }
 
+func TestDefaultAuthority(t *testing.T) {
+	target := "Non-Existent.Server:8080"
+	conn, err := Dial(target, WithInsecure())
+	if err != nil {
+		t.Fatalf("Dial(_, _) = _, %v, want _, <nil>", err)
+	}
+	conn.Close()
+	if conn.authority != target {
+		t.Fatalf("%v.authority = %v, want %v", conn, conn.authority, target)
+	}
+}
+
 func TestTLSServerNameOverwrite(t *testing.T) {
 	overwriteServerName := "over.write.server.name"
 	creds, err := credentials.NewClientTLSFromFile(tlsDir+"ca.pem", overwriteServerName)