Ticket #29851: 29851.patch

src/wp-includes/taxonomy.php

@@ -1654 +1654 @@
  *
  * @param int|string $term The term to check
  * @param string $taxonomy The taxonomy name to use
- * @param int $parent ID of parent term under which to confine the exists search.
+ * @param int $parent Optional. ID of parent term under which to confine the exists search.
  * @return mixed Returns 0 if the term does not exist. Returns the term ID if no taxonomy is specified
  *               and the term ID exists. Returns an array of the term ID and the term taxonomy ID
  *               if the taxonomy is specified and the pairing exists.
  */
-function term_exists($term, $taxonomy = '', $parent = 0) {
+function term_exists( $term, $taxonomy = '', $parent = null ) {
         global $wpdb;
 
         $select = "SELECT term_id FROM $wpdb->terms as t WHERE ";
@@ -1685 +1685 @@
         $where_fields = array($slug);
         $else_where_fields = array($term);
         if ( !empty($taxonomy) ) {
-                $parent = (int) $parent;
-                if ( $parent > 0 ) {
+                if ( is_numeric( $parent ) ) {
+                        $parent = (int) $parent;
                         $where_fields[] = $parent;
                         $else_where_fields[] = $parent;
                         $where .= ' AND tt.parent = %d';

tests/phpunit/tests/term.php

@@ -138 +138 @@
                 $this->assertEquals( $t, $found['term_id'] );
         }
 
+        public function test_term_exists_taxonomy_nonempty_parent_0_should_return_false_for_child_term() {
+                register_taxonomy( 'foo', 'post', array(
+                        'hierarchical' => true,
+                ) );
+
+                $parent_term = $this->factory->term->create( array(
+                        'taxonomy' => 'foo',
+                ) );
+
+                $t = $this->factory->term->create( array(
+                        'taxonomy' => 'foo',
+                        'parent' => $parent_term,
+                        'slug' => 'child-term',
+                ) );
+
+                $found = term_exists( 'child-term', 'foo', 0 );
+
+                _unregister_taxonomy( 'foo' );
+
+                $this->assertSame( null, $found['term_id'] );
+        }
+
         public function test_term_exists_taxonomy_nonempty_parent_nonempty_match_name() {
                 register_taxonomy( 'foo', 'post', array(
                         'hierarchical' => true,