Ticket #45220: 45220.2.diff

src/wp-includes/rest-api/endpoints/class-wp-rest-controller.php

@@ -519 +519 @@
         public function get_fields_for_response( $request ) {
                 $schema = $this->get_item_schema();
                 $fields = isset( $schema['properties'] ) ? array_keys( $schema['properties'] ) : array();
+
+                $additional_fields = $this->get_additional_fields();
+                foreach ( $additional_fields as $field_name => $field_options ) {
+                        // For back-compat, include any field with an empty schema
+                        // because it won't be present in $this->get_item_schema().
+                        if ( is_null( $field_options['schema'] ) ) {
+                                $fields[] = $field_name;
+                        }
+                }
+
                 if ( ! isset( $request['_fields'] ) ) {
                         return $fields;
                 }

tests/phpunit/tests/rest-api/rest-posts-controller.php

@@ -3365 +3365 @@
                 $wp_rest_additional_fields = array();
         }
 
+        /**
+         * @ticket 45220
+         */
+        public function test_get_additional_field_registration_null_schema() {
+                register_rest_field( 'post', 'my_custom_int', array(
+                        'schema'          => null,
+                        'get_callback'    => array( $this, 'additional_field_get_callback' ),
+                        'update_callback' => null,
+                ) );
+                $post_id = $this->factory->post->create();
+
+                // 'my_custom_int' should appear because ?_fields= isn't set.
+                $request  = new WP_REST_Request( 'GET', '/wp/v2/posts/' . $post_id );
+                $response = $this->server->dispatch( $request );
+                $this->assertArrayHasKey( 'my_custom_int', $response->data );
+
+                // 'my_custom_int' should appear because it's present in ?_fields=.
+                $request = new WP_REST_Request( 'GET', '/wp/v2/posts/' . $post_id );
+                $request->set_param( '_fields', 'title,my_custom_int' );
+                $response = $this->server->dispatch( $request );
+                $this->assertArrayHasKey( 'my_custom_int', $response->data );
+
+                // 'my_custom_int' should not appear because it's not present in ?_fields=.
+                $request = new WP_REST_Request( 'GET', '/wp/v2/posts/' . $post_id );
+                $request->set_param( '_fields', 'title' );
+                $response = $this->server->dispatch( $request );
+                $this->assertArrayNotHasKey( 'my_custom_int', $response->data );
+
+                global $wp_rest_additional_fields;
+                $wp_rest_additional_fields = array();
+        }
+
         public function test_additional_field_update_errors() {
                 $schema = array(
                         'type'        => 'integer',