Ticket #23627: add-pre_wp_nav_menu-filter.23627.diff

wp-includes/nav-menu-template.php

@@ -144 +144 @@
         $args = apply_filters( 'wp_nav_menu_args', $args );
         $args = (object) $args;
 
+        // Allow plugins to short-circuit menu output
+        $nav_menu = apply_filters( 'pre_wp_nav_menu', '', $args );
+
+        if ( ! empty( $nav_menu ) && $args->echo )
+                echo $nav_menu;
+        elseif ( ! empty( $nav_menu ) )
+                return $nav_menu;
+
         // Get the nav menu based on the requested menu
         $menu = wp_get_nav_menu_object( $args->menu );