Ticket #34721: 34721.patch

src/wp-includes/class-wp-editor.php

@@ -572 +572 @@
                                  *
                                  * @since 2.1.0
                                  *
-                                 * @param array $stylesheets Comma-delimited list of stylesheets.
+                                 * @param string $stylesheets Comma-delimited list of stylesheets.
                                  */
                                 $mce_css = trim( apply_filters( 'mce_css', implode( ',', $mce_css ) ), ' ,' );