wp_list_categories can output not well nested HTML

[chesio]

Hi,

#33460 requested an option to hide title if no categories are present. This has been implemented in [33764] and [33767].

However, [33764] introduced a bug that can result in not well nested output, because only the condition that optionally "opens" list item and starts new list has been altered, not the condition that optionally close both.

On a clean install (from trunk):

wp_list_categories([
        'child_of' => 1, // to have $categories empty
        'hide_title_if_empty' => true, // to hide title
        'show_option_none' => '', // to get only the invalid output
]);

Produces:

</ul></li>

I believe, the fix is quite straight-forward - see the patch attached.

Proposed patch for #38839

@chesio, thank you for the solid report and the patch!

In 39280:

Taxonomy: Prevent wp_list_categories() from producing not well-nested output if hide_title_if_empty is true.

Props chesio.
Fixes #38839. See #33460.