5.3 breaks counters used in submenu items

[netweblogic]

Changes in CSS for 5.3 breaks the use of counters in submenu pages. There are plugins that add counter alerts within menus for various reasons (for example, a new CPT needing revision from an admin).

Previously the snippet below would work in <5.3 and now the number is not styled:

<?php
add_action('admin_menu', function(){
        $count = '<span class="update-plugins count-10"><span class="plugin-count">10</span></span>';
        add_options_page('Example', 'Example'.$count, 'manage_options', 'example', '__return_false');
});

It might be worth creating a sub-menu css class, or at least warning devs of this breaking change in a blog post.

[netweblogic]

Breaking change here:

https://core.trac.wordpress.org/changeset?old=46332&old_path=trunk%2Fsrc%2Fwp-admin%2Fcss%2Fadmin-menu.css&new=46453&new_path=trunk%2Fsrc%2Fwp-admin%2Fcss%2Fadmin-menu.css

[SergeyBiryukov]

Introduced in [46453] as a follow-up to [46332].

The latest patch on #42201 appears to resolve the issue.

[johnbillion]

Note that this affects core's Dashboard -> Updates menu too.

[johnbillion]

In 46555:

Administration: Fix the appearance of update bubbles in submenus and when the admin menu is collapsed.

Props afercia, amolv, sabernhardt

Fixes #42201, #48294

[netweblogic]

I can confirm this does fix the problem for me on latest nightlies. Thanks all!