Ticket #38034: 38034.2.diff

src/wp-includes/class-wp-query.php

@@ -1546 +1546 @@
                         'menu_order',
                         'comment_count',
                         'rand',
+                        'post__in',
                 );
 
                 $primary_meta_key   = '';
@@ -1603 +1604 @@
                         case 'meta_value_num':
                                 $orderby_clause = "{$primary_meta_query['alias']}.meta_value+0";
                                 break;
+                        case 'post__in':
+                                if ( ! empty( $this->query_vars['post__in'] ) ) {
+                                        $orderby_clause = "FIELD({$wpdb->posts}.ID," . implode( ',', array_map( 'absint', $this->query_vars['post__in'] ) ) . ')';
+                                }
+                                break;
                         default:
                                 if ( array_key_exists( $orderby, $meta_clauses ) ) {
                                         // $orderby corresponds to a meta_query clause.
@@ -2252 +2258 @@
                         }
                 } elseif ( 'none' == $q['orderby'] ) {
                         $orderby = '';
-                } elseif ( $q['orderby'] == 'post__in' && ! empty( $post__in ) ) {
-                        $orderby = "FIELD( {$wpdb->posts}.ID, $post__in )";
                 } elseif ( $q['orderby'] == 'post_parent__in' && ! empty( $post_parent__in ) ) {
                         $orderby = "FIELD( {$wpdb->posts}.post_parent, $post_parent__in )";
                 } elseif ( $q['orderby'] == 'post_name__in' && ! empty( $post_name__in ) ) {

tests/phpunit/tests/post/query.php

@@ -174 +174 @@
                 $this->assertSame( $ordered, wp_list_pluck( $q->posts, 'ID' ) );
         }
 
+        /**
+         * @ticket 38034
+         */
+        public function test_orderby_post__in_array() {
+                $posts = self::factory()->post->create_many( 4 );
+
+                $ordered = array( $posts[2], $posts[0], $posts[3] );
+
+                $q = new WP_Query( array(
+                        'post_type' => 'any',
+                        'post__in' => $ordered,
+                        'orderby' => array( 'post__in' => 'ASC' ),
+                ) );
+                $this->assertSame( $ordered, wp_list_pluck( $q->posts, 'ID' ) );
+        }
+
+        /**
+         * @ticket 38034
+         */
+        public function test_orderby_post__in_array_with_implied_order() {
+                $posts = self::factory()->post->create_many( 4 );
+
+                $ordered = array( $posts[2], $posts[0], $posts[3] );
+
+                $q = new WP_Query( array(
+                        'post_type' => 'any',
+                        'post__in' => $ordered,
+                        'orderby' => 'post__in',
+                ) );
+                $this->assertSame( $ordered, wp_list_pluck( $q->posts, 'ID' ) );
+        }
+
         function test_post__in_attachment_ordering() {
                 $post_id    = self::factory()->post->create();
                 $att_ids    = array();