[wp-trac] [WordPress Trac] #61936: wp_get_object_terms: Unexpected return type (PHP 7.4)/fatal error (PHP 8.0+) when requesting a count

[WordPress Trac]

#61936: wp_get_object_terms: Unexpected return type (PHP 7.4)/fatal error (PHP
8.0+) when requesting a count
----------------------------+-----------------------------
 Reporter:  marian1         |       Owner:  (none)
     Type:  defect (bug)    |      Status:  new
 Priority:  normal          |   Milestone:  Future Release
Component:  Taxonomy        |     Version:  2.3
 Severity:  normal          |  Resolution:
 Keywords:  has-unit-tests  |     Focuses:
----------------------------+-----------------------------
Changes (by marian1):

 * keywords:  has-patch has-unit-tests => has-unit-tests


Comment:

 This is a first step. However, while examining this issue, I found that
 this entire section seems incorrect:

 {{{#!php
 /*
  * When one or more queried taxonomies are registered with an 'args'
 array,
  * those parameters override the `$args` passed to this function.
  */
 $terms = array();
 if ( count( $taxonomies ) > 1 ) {
     foreach ( $taxonomies as $index => $taxonomy ) {
         $t = get_taxonomy( $taxonomy );
         if ( isset( $t->args ) && is_array( $t->args ) && array_merge(
 $args, $t->args ) != $args ) {
             unset( $taxonomies[ $index ] );
             $terms = array_merge( $terms, wp_get_object_terms(
 $object_ids, $taxonomy, array_merge( $args, $t->args ) ) );
         }
     }
 } else {
     $t = get_taxonomy( $taxonomies[0] );
     if ( isset( $t->args ) && is_array( $t->args ) ) {
         $args = array_merge( $args, $t->args );
     }
 }
 }}}

 The `$args` that the taxonomies are registered with are located in
 `$t->args['args']`, not `$t->args`. Therefore, the condition `array_merge(
 $args, $t->args ) != $args )` is always true, but the incorrect array is
 merged. The statement "those parameters override the `$args` passed to
 this function" will never occur, except for `'hierarchical'`, which is
 part of both arrays. However, I am unsure whether this overriding should
 occur at all. If the `array_merge` worked as intended, each taxonomy could
 have a different `'fields'` value, resulting in a relatively unpredictable
 return type.

 While the function now returns the expected count when requesting a count,
 the actual value is still incorrect when more than one `object_id` is
 associated with a term due to double counting. However, I wanted to
 discuss this new issue first before continuing.

 It's also necessary to review the other functions that call
 `wp_get_object_terms()`.

-- 
Ticket URL: <https://core.trac.wordpress.org/ticket/61936#comment:3>
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