0.4 fix tls address panic (#478)

* 0.4: fix panic when TLS is enabled

* 0.4: fix panic when establishing TLS connections

* cleanup

* Update transport_test.go

Co-authored-by: Steve van Loben Sels <[email protected]>

* validate that an error is returned

Co-authored-by: Steve van Loben Sels <[email protected]>

Author: Achille

transport.go

@@ -997,6 +997,10 @@ func (g *connGroup) connect(ctx context.Context) (*conn, error) {
 	for i := range address {
 		netConn, err = g.pool.dial(ctx, network[i], address[i])
 		if err == nil {
+			netAddr = &networkAddress{
+				network: network[i],
+				address: address[i],
+			}
 			break
 		}
 	}

transport_test.go

@@ -0,0 +1,34 @@
+package kafka
+
+import (
+	"context"
+	"crypto/tls"
+	"net"
+	"testing"
+)
+
+func TestIssue477(t *testing.T) {
+	// This test verifies that a connection attempt with a minimal TLS
+	// configuration does not panic.
+	l, err := net.Listen("tcp", "127.0.0.1:0")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer l.Close()
+
+	cg := connGroup{
+		addr: l.Addr(),
+		pool: &connPool{
+			dial: defaultDialer.DialContext,
+			tls:  &tls.Config{},
+		},
+	}
+
+	if _, err := cg.connect(context.Background()); err != nil {
+		// An error is expected here because we are not actually establishing
+		// a TLS connection to a kafka broker.
+		t.Log(err)
+	} else {
+		t.Error("no error was reported when attempting to establish a TLS connection to a non-TLS endpoint")
+	}
+}