Command Palette: Top-level menus registered without a callback lead to "Cannot load {slug}"

[yashjawale]

wp_enqueue_command_palette_assets() builds each top-level "Go to" command URL with menu_page_url( $menu_slug ). When a plugin registers a top-level menu with a null callback (e.g. WooCommerce's woocommerce and woocommerce-marketing), no page hook exists, so admin.php?page={slug} ends in wp_die( 'Cannot load {slug}.' ) (HTTP 500).

The admin menu avoids this because _wp_menu_output() links such items to their first submenu ([4481]). The palette doesn't.

Originally reported in gutenberg repository at ​https://github.com/WordPress/gutenberg/issues/86646

Steps to reproduce

1. Add as a mu-plugin (or activate WooCommerce):

   add_action( 'admin_menu', function () {
           add_menu_page( 'Parent', 'Parent', 'manage_options', 'null-parent', null );
           add_submenu_page( 'null-parent', 'Child', 'Child', 'manage_options', 'null-child', function () { echo 'ok'; } );
           // Remove the auto-added parent submenu, as WooCommerce does.
           remove_submenu_page( 'null-parent', 'null-parent' );
   } );
   

2. Open the Command Palette and choose "Parent".

Expected: the "Child" screen, as the admin menu link opens.
Actual: "Cannot load null-parent."

Proposed fix

If a top-level slug has submenus but no page hook (get_plugin_page_hook( $slug, 'admin.php' )), use the first accessible submenu's URL, and skip the command if there is none. Menus with their own page are unchanged.

[yashjawale]

Screencast of behavior when selecting WooCommerce parent in command palette

Top-level menus without a page of their own, registered with a null callback, now get a Command Palette "Go to" command that links to their first accessible submenu, as the admin menu does. Before, the command pointed at admin.php?page={slug}, which fails with "Cannot load {slug}."

Use of AI Tools

AI assistance: Yes
Tool(s): Claude Code
Model(s): Opus 5.5
Used for: Drafting changes, final edits manually tested & reviewed by me

[yashjawale]

Screencast after the patch