net: fix Close of autobind unix listener

Fixes #6455.

R=mikioh.mikioh, rsc
CC=golang-dev
https://golang.org/cl/13457058

src/pkg/net/unix_test.go

@@ -107,7 +107,7 @@ func TestReadUnixgramWithZeroBytesBuffer(t *testing.T) {
 	}
 }
 
-func TestUnixAutobind(t *testing.T) {
+func TestUnixgramAutobind(t *testing.T) {
 	if runtime.GOOS != "linux" {
 		t.Skip("skipping: autobind is linux only")
 	}
@@ -139,6 +139,18 @@ func TestUnixAutobind(t *testing.T) {
 	}
 }
 
+func TestUnixAutobindClose(t *testing.T) {
+	if runtime.GOOS != "linux" {
+		t.Skip("skipping: autobind is linux only")
+	}
+	laddr := &UnixAddr{Name: "", Net: "unix"}
+	ln, err := ListenUnix("unix", laddr)
+	if err != nil {
+		t.Fatalf("ListenUnix failed: %v", err)
+	}
+	ln.Close()
+}
+
 func TestUnixConnLocalAndRemoteNames(t *testing.T) {
 	for _, laddr := range []string{"", testUnixAddr()} {
 		laddr := laddr

src/pkg/net/unixsock_posix.go

@@ -271,7 +271,7 @@ func ListenUnix(net string, laddr *UnixAddr) (*UnixListener, error) {
 	if err != nil {
 		return nil, &OpError{Op: "listen", Net: net, Addr: laddr, Err: err}
 	}
-	return &UnixListener{fd, laddr.Name}, nil
+	return &UnixListener{fd, fd.laddr.String()}, nil
 }
 
 // AcceptUnix accepts the next incoming call and returns the new