Ticket #16799: use-excerpts-in-menu-textarea.diff

wp-includes/nav-menu.php

@@ -585 +585 @@
                         $menu_item->target = empty( $menu_item->target ) ? get_post_meta( $menu_item->ID, '_menu_item_target', true ) : $menu_item->target;
 
                         $menu_item->attr_title = empty( $menu_item->attr_title ) ? apply_filters( 'nav_menu_attr_title', $menu_item->post_excerpt ) : $menu_item->attr_title;
-                        $menu_item->description = empty( $menu_item->description ) ? apply_filters( 'nav_menu_description', $menu_item->post_content ) : $menu_item->description;
+                        $excerpt = empty( $menu_item->post_excerpt ) ? wp_trim_words( $menu_item->post_content ) : $menu_item->post_excerpt;
+                        $menu_item->description = empty( $menu_item->description ) ? apply_filters( 'nav_menu_description', $excerpt ) : $menu_item->description;
 
                         $menu_item->classes = empty( $menu_item->classes ) ? (array) get_post_meta( $menu_item->ID, '_menu_item_classes', true ) : $menu_item->classes;
                         $menu_item->xfn = empty( $menu_item->xfn ) ? get_post_meta( $menu_item->ID, '_menu_item_xfn', true ) : $menu_item->xfn;