The 'get_users' function triggers a fatal error if a role is added without any capability assigned.

[nazsabuz]

Steps to reproduce

1. Add a custom user role, and pass null to the capabilities argument. e.g.

   <?php
   function add_custom_role_without_capabilities() {
           add_role( 'ola', 'Ola', null );
   }
   add_action( 'init', 'add_custom_role_without_capabilities' );
   

2. Now, call the get_users function with 'capability' args. e.g.

   <?php
   $users = get_users( [
           'capability' => [ 'edit_posts' ],
   ] );
   

You should see a fatal error.

Uncaught Error: array_filter(): Argument #1 ($array) must be of type array, null given in /wp/wp-includes/class-wp-user-query.php on line 487

Trac ticket: https://core.trac.wordpress.org/ticket/60931

[jorbin]

If you are calling add_role with null $capabilities you are doing it wrong and I don't think this is something that should be hidden. I think causing add_role to fail in this situation is a better solution.

Changing the milestone to 2.0 since that is when add_role was added.

Trac ticket: https://core.trac.wordpress.org/ticket/60931

[nazsabuz]

Got it, a new PR has been created.