[wp-trac] [WordPress Trac] #55887: Calling get_terms() with exact same args (most important is exclude_tree) returns unexpected results from runtime cache (second call)

[WordPress Trac]

#55887: Calling get_terms() with exact same args (most important is exclude_tree)
returns unexpected results from runtime cache (second call)
--------------------------+------------------------------
 Reporter:  szaqal21      |       Owner:  (none)
     Type:  defect (bug)  |      Status:  new
 Priority:  normal        |   Milestone:  Awaiting Review
Component:  Taxonomy      |     Version:  6.0
 Severity:  normal        |  Resolution:
 Keywords:                |     Focuses:
--------------------------+------------------------------

Comment (by szaqal21):

 After some tests on **WP_Term_Query::get_terms()**, this query

 {{{
 get_terms(array('taxonomy' => 'category', 'exclude_tree' => array(111),
 'hide_empty' => false, 'fields' => 'names'))
 }}}

 does the following, first calls another **get_terms()** to fill
 **$exclusions**

 {{{
 if ( ! empty( $exclude_tree ) ) {
                         $exclude_tree      = wp_parse_id_list(
 $exclude_tree );
                         $excluded_children = $exclude_tree;
                         foreach ( $exclude_tree as $extrunk ) {
                                 $excluded_children = array_merge(
                                         $excluded_children,
                                         (array) get_terms(
                                                 array(
                                                         'taxonomy'   =>
 reset( $taxonomies ),
                                                         'child_of'   =>
 (int) $extrunk,
                                                         'fields'     =>
 'ids',
                                                         'hide_empty' => 0,
                                                 )
                                         )
                                 );
                         }
                         $exclusions = array_merge( $excluded_children,
 $exclusions );
                 }
 }}}

 and I think here's the problem, adding some output before

 {{{
 ...
 // ADDED OUTPUT BEFORE ADDING TO CACHE

 wp_cache_add( $cache_key, $terms, 'terms' );
                 $terms = $this->format_terms( $term_objects, $_fields );

                 $this->terms = $terms;
                 return $this->terms;
 }
 }}}

 in **WP_Term_Query::get_terms()** I got these results:

 {{{
 var_dump($this->request);
 string(179) " SELECT t.term_id FROM wptest_terms AS t INNER JOIN
 wptest_term_taxonomy AS tt ON t.term_id = tt.term_id WHERE tt.taxonomy IN
 ('category') ORDER BY t.name ASC "
 }}}


 {{{
 var_dump($cache_args);
 array(31) { ["taxonomy"]=> array(1) { [0]=> string(8) "category" }
 ["object_ids"]=> array(0) { } ["orderby"]=> string(4) "name" ["order"]=>
 string(3) "ASC" ["hide_empty"]=> int(0) ["include"]=> array(0) { }
 ["exclude"]=> array(0) { } ["exclude_tree"]=> array(0) { } ["number"]=>
 int(0) ["offset"]=> int(0) ["fields"]=> string(3) "all" ["count"]=>
 bool(false) ["name"]=> array(0) { } ["slug"]=> array(0) { }
 ["term_taxonomy_id"]=> array(0) { } ["hierarchical"]=> bool(true)
 ["search"]=> string(0) "" ["name__like"]=> string(0) ""
 ["description__like"]=> string(0) "" ["get"]=> string(0) "" ["child_of"]=>
 int(111) ["parent"]=> string(0) "" ["childless"]=> bool(false)
 ["cache_domain"]=> string(4) "core" ["meta_query"]=> string(0) ""
 ["meta_key"]=> string(0) "" ["meta_value"]=> string(0) "" ["meta_type"]=>
 string(0) "" ["meta_compare"]=> string(0) "" ["parent__in"]=> array(0) { }
 ["parent__not_in"]=> array(0) { } }
 }}}


 {{{
 var_dump($terms);
 array(7) { [0]=> object(stdClass)#359 (1) { ["term_id"]=> string(3) "110"
 } [1]=> object(stdClass)#360 (1) { ["term_id"]=> string(3) "113" } [2]=>
 object(stdClass)#361 (1) { ["term_id"]=> string(3) "111" } [3]=>
 object(stdClass)#362 (1) { ["term_id"]=> string(3) "114" } [4]=>
 object(stdClass)#363 (1) { ["term_id"]=> string(1) "1" } [5]=>
 object(stdClass)#364 (1) { ["term_id"]=> string(3) "112" } [6]=>
 object(stdClass)#365 (1) { ["term_id"]=> string(3) "115" } }
 }}}


 {{{
 var_dump($term_objects);
 array(1) { [0]=> object(WP_Term)#375 (10) { ["term_id"]=> int(114)
 ["name"]=> string(2) "B1" ["slug"]=> string(2) "b1" ["term_group"]=>
 int(0) ["term_taxonomy_id"]=> int(114) ["taxonomy"]=> string(8) "category"
 ["description"]=> string(0) "" ["parent"]=> int(111) ["count"]=> int(0)
 ["filter"]=> string(3) "raw" } }
 }}}

 in **$cache_args** you can see that **child_of = 111** so this query
 should return children for term_id = 111 and it does return proper result
 which is **$term_objects** but this is not what is being added to cache,
 **$terms** var is, as you can see **$terms** stores result of
 **$wpdb->get_results( $this->request );** which is result of


 {{{
 SELECT t.term_id FROM wptest_terms AS t INNER JOIN wptest_term_taxonomy AS
 tt ON t.term_id = tt.term_id WHERE tt.taxonomy IN ('category') ORDER BY
 t.name ASC
 }}}

 that is all (7) terms in this taxonomy, **$term_objects** is the right
 list of terms limited to specific parent (child_of = 111).

 Calling same get_terms() as previously second time results exclusion of
 all (7) terms (result from cache).

-- 
Ticket URL: <https://core.trac.wordpress.org/ticket/55887#comment:1>
WordPress Trac <https://core.trac.wordpress.org/>
WordPress publishing platform