Update Global Styles endpoint to use Gutenberg callback and theme jso…

…n resolver

lib/compat/wordpress-6.0/class-gutenberg-rest-global-styles-controller.php

@@ -16,6 +16,32 @@ class Gutenberg_REST_Global_Styles_Controller extends WP_REST_Global_Styles_Cont
 	 * @return void
 	 */
 	public function register_routes() {
+		register_rest_route(
+			$this->namespace,
+			// The route.
+			sprintf(
+				'/%s/themes/(?P<stylesheet>%s)',
+				$this->rest_base,
+				// Matches theme's directory: `/themes/<subdirectory>/<theme>/` or `/themes/<theme>/`.
+				// Excludes invalid directory name characters: `/:<>*?"|`.
+				'[^\/:<>\*\?"\|]+(?:\/[^\/:<>\*\?"\|]+)?'
+			),
+			array(
+				array(
+					'methods'             => WP_REST_Server::READABLE,
+					'callback'            => array( $this, 'get_theme_item' ),
+					'permission_callback' => array( $this, 'get_theme_item_permissions_check' ),
+					'args'                => array(
+						'stylesheet' => array(
+							'description'       => __( 'The theme identifier' ),
+							'type'              => 'string',
+							'sanitize_callback' => array( $this, '_sanitize_global_styles_callback' ),
+						),
+					),
+				),
+			)
+		);
+
 		// List themes global styles.
 		register_rest_route(
 			$this->namespace,

lib/compat/wordpress-6.0/class-wp-theme-json-resolver-gutenberg.php

@@ -16,6 +16,22 @@
  * @access private
  */
 class WP_Theme_JSON_Resolver_Gutenberg extends WP_Theme_JSON_Resolver_5_9 {
+	public static function get_merged_data( $origin = 'custom' ) {
+		if ( is_array( $origin ) ) {
+			_deprecated_argument( __FUNCTION__, '5.9' );
+		}
+
+		$result = new WP_Theme_JSON_Gutenberg();
+		$result->merge( self::get_core_data() );
+		$result->merge( self::get_theme_data() );
+
+		if ( 'custom' === $origin ) {
+			$result->merge( self::get_user_data() );
+		}
+
+		return $result;
+	}
+
 
 	/**
 	 * Returns the theme's data.