Ticket #57903: 57903.diff

src/wp-includes/blocks.php

@@ -260 +260 @@
         if ( $has_style_file ) {
                 wp_style_add_data( $style_handle, 'path', $style_path_norm );
 
-                $rtl_file = str_replace( "{$suffix}.css", "-rtl{$suffix}.css", $style_path_norm );
+                if ( $is_core_block ) {
+                        $rtl_file = str_replace( "{$suffix}.css", "-rtl{$suffix}.css", $style_path_norm );
+                } else {
+                        $rtl_file = str_replace( ".css", "-rtl.css", $style_path_norm );
+                }
 
                 if ( is_rtl() && file_exists( $rtl_file ) ) {
                         wp_style_add_data( $style_handle, 'rtl', 'replace' );