s426001: don't check RemoteAddr in unix conn

Summary:
D58133843 changed error conditions.

On MacOS Unix Socket connections don't have RemoteAddr set, which led to error (s426001)

Reviewed By: awalterschulze

Differential Revision: D58582532

fbshipit-source-id: 93f40ebdc7bf115a9de28805fbb611310c2cfe66

thrift/lib/go/thrift/socket.go

@@ -90,6 +90,10 @@ func NewSocket(options ...SocketOption) (net.Conn, error) {
 		}
 	}
 
+	if _, ok := socket.conn.(*net.UnixConn); ok {
+		return socket, nil
+	}
+
 	if socket.conn.RemoteAddr().String() == "" {
 		return nil, errors.New("must supply either an address or a connection")
 	}

thrift/lib/go/thrift/socket_test.go

@@ -17,6 +17,7 @@
 package thrift
 
 import (
+	"net"
 	"runtime"
 	"testing"
 )
@@ -37,3 +38,24 @@ func TestNewSocket(t *testing.T) {
 		t.Errorf("wrong address: %s", addr)
 	}
 }
+
+func TestNewSocketUnix(t *testing.T) {
+	path := t.TempDir() + "/test.sock"
+
+	l, err := net.Listen("unix", path)
+	if err != nil {
+		t.Fatalf("Cannot listen on unix socket %q: %v", path, err)
+	}
+	defer l.Close()
+
+	conn, err := net.Dial("unix", path)
+	if err != nil {
+		t.Fatalf("Cannot dial unix socket %q: %v", path, err)
+	}
+
+	s, err := NewSocket(SocketConn(conn))
+	if err != nil {
+		t.Fatalf("Cannot create new socket: %v", err)
+	}
+	defer s.Close()
+}