Docs: Clarify custom-fields support requirement for viewing custom post meta in REST API.

Fixes #47866.

Built from https://develop.svn.wordpress.org/trunk@45786


git-svn-id: http://core.svn.wordpress.org/trunk@45597 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/meta.php

@@ -1129,7 +1129,9 @@ function sanitize_meta( $meta_key, $meta_value, $object_type, $object_subtype =
  *     @type bool   $single            Whether the meta key has one value per object, or an array of values per object.
  *     @type string $sanitize_callback A function or method to call when sanitizing `$meta_key` data.
  *     @type string $auth_callback     Optional. A function or method to call when performing edit_post_meta, add_post_meta, and delete_post_meta capability checks.
- *     @type bool   $show_in_rest      Whether data associated with this meta key can be considered public.
+ *     @type bool   $show_in_rest      Whether data associated with this meta key can be considered public and
+ *                                     should be accessible via the REST API. A custom post type must also declare
+ *                                     support for custom fields for registered meta to be accessible via REST.
  * }
  * @param string|array $deprecated Deprecated. Use `$args` instead.
  *

wp-includes/version.php

@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.3-alpha-45785';
+$wp_version = '5.3-alpha-45786';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.