Fix Dial() host:port parsing to handle IPv6 literals.

Fixes #184

Signed-off-by: Alan Conway <aconway@redhat.com>

Author: alanconway

client.go

@@ -44,10 +44,9 @@ func Dial(addr string, opts ...ConnOption) (*Client, error) {
 	if err != nil {
 		return nil, err
 	}
-	host, port, err := net.SplitHostPort(u.Host)
-	if err != nil {
-		host = u.Host
-		port = "5672" // use default port values if parse fails
+	host, port := u.Hostname(), u.Port()
+	if port == "" {
+		port = "5672"
 		if u.Scheme == "amqps" {
 			port = "5671"
 		}
@@ -74,11 +73,11 @@ func Dial(addr string, opts ...ConnOption) (*Client, error) {
 	dialer := &net.Dialer{Timeout: c.connectTimeout}
 	switch u.Scheme {
 	case "amqp", "":
-		c.net, err = dialer.Dial("tcp", host+":"+port)
+		c.net, err = dialer.Dial("tcp", net.JoinHostPort(host, port))
 	case "amqps":
 		c.initTLSConfig()
 		c.tlsNegotiation = false
-		c.net, err = tls.DialWithDialer(dialer, "tcp", host+":"+port, c.tlsConfig)
+		c.net, err = tls.DialWithDialer(dialer, "tcp", net.JoinHostPort(host, port), c.tlsConfig)
 	default:
 		return nil, errorErrorf("unsupported scheme %q", u.Scheme)
 	}

local_test.go

@@ -0,0 +1,37 @@
+// +build local
+
+package amqp_test
+
+import (
+	"net"
+	"testing"
+
+	"pack.ag/amqp"
+)
+
+// Tests that require a local broker running on the standard AMQP port.
+
+func TestDial_IPV6(t *testing.T) {
+	if c, err := amqp.Dial("amqp://localhost"); err != nil {
+		t.Skip("can't connect to local AMQP server")
+	} else {
+		c.Close()
+	}
+	l, err := net.Listen("tcp6", "[::]:0")
+	if err != nil {
+		t.Skip("ipv6 not supported")
+	}
+	l.Close()
+
+	for _, u := range []string{"amqp://[::]:5672", "amqp://[::]"} {
+		u := u // Don't  use range variable in func literal.
+		t.Run(u, func(t *testing.T) {
+			c, err := amqp.Dial(u)
+			if err != nil {
+				t.Errorf("%q: %v", u, err)
+			} else {
+				c.Close()
+			}
+		})
+	}
+}