Renote visibility (#3290)

src/remote/activitypub/renderer/index.ts

@@ -2,6 +2,8 @@ import config from '../../../config';
 import * as uuid from 'uuid';
 
 export default (x: any) => {
+	if (x == null) return null;
+
 	if (x !== null && typeof x === 'object' && x.id == null) {
 		x.id = `${config.url}/${uuid.v4()}`;
 	}