Plugins breaks get_users method

Hi there,

we got a report for our plugin Matomo ( see https://github.com/matomo-org/wp-matomo/issues/365 ) that approving a member results in an exception triggered by our plugin.

After being able to reproduce it and after some debugging session we noticed that the plugin overwrites the pre_user_query in the method filter_users_by_status while approving a user.

As a result of this, when we call get_users([]) in our plugin, then we don’t get the list of all users but only one WP user. The user that is being approved. This then causes a lot of deletion going on in our plugin since it thinks the other WP users were deleted when in reality a filter in your plugin caused this issue that not all users were returned.

Is there any chance you could adjust your code to not break other plugins? Maybe you could add a um_custom or some other flag to your get_users queries and only manipulate the $query_where for your own get_users calls like below? This way it wouldn’t affect our get_users calls. Thanks for considering this!

	    add_action('pre_user_query', function ($query){
		    /** @var \WP_User_Query $query */
		    if ($query->get('um_custom')) {
			    $query->query_where = '...';
		    }
	    });
	    $options['um_custom'] = '1';
	    $users_custom = get_users( $options );