Ticket #36985: 36985.patch

wp-includes/theme.php

@@ -1425 +1425 @@
 function add_editor_style( $stylesheet = 'editor-style.css' ) {
         add_theme_support( 'editor-style' );
 
-        if ( ! is_admin() )
+        if ( (bool) apply_filters( 'disable_editor_style', ! is_admin() ) ) {
                 return;
+        }
 
         global $editor_styles;
         $editor_styles = (array) $editor_styles;