Introduce get_term_ancestors()

[scribu]

We have get_term_children(), but no get_term_ancestors().

It can be used in Core to cut down the queries done by cat_is_ancestor_of() and will be useful in and off itself. Example: #12898 #10277

See #12443

That's an interesting approach, but I think you're going to eat up all the memory with a decent number of categories.

Introduce get_term_ancestors() and use in cat_is_ancestor_of()

Replying to filosofo:

That's an interesting approach, but I think you're going to eat up all the memory with a decent number of categories.

I don't think that's likely, since only two integer fields are retrieved: ID and parent.

Besides, wp_list_categories() retrieves all the fields for all the categories and I haven't heard any memory limit issues about that.

I think #12443 is the better way to go.