get_categories filter not run on cached get_categories() hits

[markjaquith]

get_categories() runs get_categories filter on a cache miss, but not on cache hits.

[markjaquith]

(In [4848]) run get_categories filter on cached get_categories hits. fixes #3728

[markjaquith]

(In [4849]) run get_categories filter on cached get_categories hits. fixes #3728

[robertaccettura]

I have this problem where

wp_list_categories('show_count=1&title_li=<h2>Categories</h2>');

Gives "No categories". When caching is enabled. Thinking this was the same issue I applied this patch to 2.1, but no dice.

[markjaquith]

robert,

Likely a different issue that was fixed for 2.1.1 in [4857]