Ticket #41010: 41010.3.patch

src/wp-includes/taxonomy.php

@@ -1917 +1917 @@
         $args['taxonomy'] = $taxonomies;
         $args['object_ids'] = $object_ids;
 
-        $terms = array_merge( $terms, get_terms( $args ) );
+        // Taxonomies registered without an 'args' param are handled here.
+        if ( ! empty( $taxonomies ) ) {
+                $terms = array_merge( $terms, get_terms( $args ) );
+        }
 
         /**
          * Filters the terms for a given object or objects.

tests/phpunit/tests/term/wpGetObjectTerms.php

@@ -760 +760 @@
                 $args['orderby'] = 'term_order';
                 return $args;
         }
+
+        /**
+         * @ticket 41010
+         */
+        public function test_duplicate_terms_should_not_be_returned_when_passed_multiple_taxonomies_registered_with_args_array() {
+                $taxonomy1 = 'wptests_tax';
+                $taxonomy2 = 'wptests_tax_2';
+
+                // Any non-empty 'args' array triggers the bug.
+                $taxonomy_arguments = array(
+                        'args' => array( 0 ),
+                );
+
+                register_taxonomy( $taxonomy1, 'post', $taxonomy_arguments );
+                register_taxonomy( $taxonomy2, 'post', $taxonomy_arguments );
+
+                $post_id = self::factory()->post->create();
+                $term_1_id = self::factory()->term->create( array(
+                        'taxonomy' => $taxonomy1,
+                ) );
+                $term_2_id = self::factory()->term->create( array(
+                        'taxonomy' => $taxonomy2,
+                ) );
+
+                wp_set_object_terms( $post_id, $term_1_id, $taxonomy1 );
+                wp_set_object_terms( $post_id, $term_2_id, $taxonomy2 );
+
+                $expected = array( $term_1_id, $term_2_id );
+
+                $actual = wp_get_object_terms( $post_id, array( $taxonomy1, $taxonomy2 ), array(
+                        'orderby' => 'term_id',
+                        'fields' => 'ids',
+                ) );
+
+                $this->assertEqualSets( $expected, $actual );
+        }
 }