+ // HTML maxlength uses "UTF-16 code units", which means that characters outside BMP
+ // (e.g. emojis) count for two each. This limit is overridden in JS to instead count
+ // Unicode codepoints (or 255 UTF-8 bytes for old schema).
+ $conf = $this->getContext()->getConfig();
+ $oldCommentSchema = $conf->get( 'CommentTableSchemaMigrationStage' ) === MIGRATION_OLD;