Screen reader shortcut links generated by _render() from WP_Admin_Bar class should use rel="nofolow"

[Marko-M]

Screen reader related links generated by _render() from WP_Admin_Bar class assume toolbar is being shown only to logged in users. When toolbar is being shown to visitors using

function my_set_current_user() {
    if(!is_user_logged_in()){
        add_filter('show_admin_bar', '__return_true');
    }
}
add_action('set_current_user', 'my_set_current_user');

search engines report 403 error code on every page of the website when trying to follow wp_logout_url() from one of these links (Logout link). Including rel="nofollow" into _render() should avoid this.

[SergeyBiryukov]

#23859 was marked as a duplicate.

[nacin]

We should instead avoid rendering such a link entirely when the user isn't logged in.

[nacin]

In 24442:

Don't render the screen reader shortcut 'Log Out' link in the toolbar when the user is not logged in.

props SergeyBiryukov.
fixes #23178.

[nacin]

In 24443:

Don't render the screen reader shortcut 'Log Out' link in the toolbar when the user is not logged in.

Merges [24442] to the 3.5 branch.

props SergeyBiryukov.
fixes #23178.