get_terms with child_of only works with uninterrupted hierarchies

[eclev91]

Similar to #14477 -

If I use get_terms() with both search and child_of, the filtered results are passed to _get_term_children(), and if those results don't include an uninterrupted heirarchy, it returns an empty array. Something like...

get_terms(array(
   'search'=>$search_term,
   'child_of'=>6
));

won't return grandchildren of 6 that match $search_term.

[majemedia]

I have a workaround that just worked for me.

I had to delete an option from the DB before my child_of search worked.

Option Name: {taxonomy_name}_children

delete_option( {taxonomy_name}_children )

Then my child_of search worked wonderfully as described.

My situation:

• Importing thousands of categories in multiple taxonomies.
• Searching through those to assign posts, map terms from multiple taxonomies together (using WP as a tagging engine)
• child_of wasn't working no matter what I did and did not describe in the args
• deleted the option for all the taxonomies I am working with and it started working for grandchildren as described in the code.