[wp-trac] [WordPress Trac] #52904: WP_Term_Query does not return deeper descendants of child_of when direct children of child_of are not part of the results

[WordPress Trac]

#52904: WP_Term_Query does not return deeper descendants of child_of when direct
children of child_of are not part of the results
--------------------------+-----------------------------
 Reporter:  xParham       |      Owner:  (none)
     Type:  defect (bug)  |     Status:  new
 Priority:  normal        |  Milestone:  Awaiting Review
Component:  Taxonomy      |    Version:
 Severity:  major         |   Keywords:  needs-patch
  Focuses:                |
--------------------------+-----------------------------
 Let's say for the hierarchical taxonomy `mytax` we have the following
 terms and term ids(in parentheses):


 {{{
 - A (1)
 -- AB (2)
 --- ABC (3)
 - B (4)
 -- BD (5)
 -- ABC (6)
 }}}

 The following query works fine and it returns both terms with ID 2 and 3
 {{{
 print_r(
     get_terms(
         [
             'taxonomy' => 'mytax',
             'name__like' => 'AB',
             'child_of' => 1,
             'hide_empty' => false
         ]
     )
 );
 }}}

 However, the following query returns an empty array (since term_id=2 will
 no longer be in the results):
 {{{
 print_r(
     get_terms(
         [
             'taxonomy' => 'mytax',
             'name__like' => 'ABC',
             'child_of' => 1,
             'hide_empty' => false
         ]
     )
 );
 }}}

 but it is expected that it returns the term ABC with term_id=3.

 This seems to be a bug with the logic in `_get_term_children()` where if
 direct children of the asking ancestor are not within the initial set of
 the terms, the recursion will never happen and deeper descendants are then
 removed from the query results.

-- 
Ticket URL: <https://core.trac.wordpress.org/ticket/52904>
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