diff -r 3d4e9c994f10 -r a86126ab1dd4 wp/wp-includes/class-wp-simplepie-sanitize-kses.php
--- a/wp/wp-includes/class-wp-simplepie-sanitize-kses.php	Tue Oct 22 16:11:46 2019 +0200
+++ b/wp/wp-includes/class-wp-simplepie-sanitize-kses.php	Tue Dec 15 13:49:49 2020 +0100
@@ -46,7 +46,7 @@
 		}
 		if ( $type & ( SIMPLEPIE_CONSTRUCT_HTML | SIMPLEPIE_CONSTRUCT_XHTML ) ) {
 			$data = wp_kses_post( $data );
-			if ( $this->output_encoding !== 'UTF-8' ) {
+			if ( 'UTF-8' !== $this->output_encoding ) {
 				$data = $this->registry->call( 'Misc', 'change_encoding', array( $data, 'UTF-8', $this->output_encoding ) );
 			}
 			return $data;