REST API: Permit access to the themes controller if user can edit any post type.

Check a more exhaustive list of post type editing caps beyond "edit_post" to ensure custom user roles with access to to specific post types may still use block editor functionality depending on theme features.

Props miyauchi, TimothyBlynJacobs.
Fixes #46723.

Built from https://develop.svn.wordpress.org/trunk@47361


git-svn-id: http://core.svn.wordpress.org/trunk@47148 1a063a9b-81f0-0310-95a4-ce76da25c4cd

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

@@ -58,7 +58,16 @@ class WP_REST_Themes_Controller extends WP_REST_Controller {
 	 * @return true|WP_Error True if the request has read access for the item, otherwise WP_Error object.
 	 */
 	public function get_items_permissions_check( $request ) {
-		if ( ! is_user_logged_in() || ! current_user_can( 'edit_posts' ) ) {
+		if ( current_user_can( 'edit_posts' ) ) {
+			return true;
+		}
+
+		foreach ( get_post_types( array( 'show_in_rest' => true ), 'objects' ) as $post_type ) {
+			if ( current_user_can( $post_type->cap->edit_posts ) ) {
+				return true;
+			}
+		}
+
 		return new WP_Error(
 			'rest_user_cannot_view',
 			__( 'Sorry, you are not allowed to view themes.' ),
@@ -66,9 +75,6 @@ class WP_REST_Themes_Controller extends WP_REST_Controller {
 		);
 	}
 
-		return true;
-	}
-
 	/**
 	 * Retrieves a collection of themes.
 	 *

wp-includes/version.php

@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.4-beta2-47360';
+$wp_version = '5.4-beta2-47361';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.