[wp-trac] [WordPress Trac] #33281: get_term_by() not returning false if ID does not exist

[WordPress Trac]

#33281: get_term_by() not returning false if ID does not exist
--------------------------+-----------------------------
 Reporter:  charlestonsw  |      Owner:
     Type:  defect (bug)  |     Status:  new
 Priority:  normal        |  Milestone:  Awaiting Review
Component:  Taxonomy      |    Version:  trunk
 Severity:  normal        |   Keywords:
  Focuses:                |
--------------------------+-----------------------------
 get_term_by() should return false if a specified ID does not exist within
 a custom taxonomy.   Instead an empty array (null) is returned.

 Example:
 {{{
 ...
 $category_array = get_term_by( 'id' , $term_id , SLPlus::locationTaxonomy,
 ARRAY_A );
 if ( $category_array === false ) {
 $this->debugMP('msg',  "Tagalong term ID {$term_id} does not exist." );
 }
 }}}

 When passing term_id value of 2, which does not exist in the terms tables,
 this should return false.  Instead null is returned.

 The issue originates in get_term() which returns null in two cases versus
 throwing a WP_Error.

 From get_term()

 {{{
 ...
                 if ( is_object($term) )
                         $term = $term->term_id;
                 if ( !$term = (int) $term )
                         return null;
                 if ( ! $_term = wp_cache_get( $term, $taxonomy ) ) {
                         $_term = $wpdb->get_row( $wpdb->prepare( "SELECT
 t.*, tt.* FROM $wpdb->terms AS t INNER JOIN $wpdb->term_taxonomy AS tt ON
 t.term_id = tt.term_id WHERE tt.taxonomy = %s AND t.term_id = %d LIMIT 1",
 $taxonomy, $term) );
                         if ( ! $_term )
                                 return null;
 ...

 }}}


 In those two cases, one of which is exactly the "term ID does not exist in
 the specified taxonomy" get_term_by should return false.   However the
 return logic does not catch the null value:

 From get_term_by():

 {{{
 ...
                 $term = get_term( (int) $value, $taxonomy, $output,
 $filter );
                 if ( is_wp_error( $term ) )
                         $term = false;
                 return $term;
 ...
 }}}

 This should be:

 {{{
 ...
                 $term = get_term( (int) $value, $taxonomy, $output,
 $filter );
                 if ( is_wp_error( $term ) || is_null( $term ) )
                         $term = false;
                 return $term;
 ...
 }}}



 WP Version: You are using a development version (4.3-RC2-33572-src).

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Ticket URL: <https://core.trac.wordpress.org/ticket/33281>
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