Rebase trunk.

lib/class-wp-theme-json-resolver-gutenberg.php

@@ -670,24 +670,48 @@ public static function clean_cached_data() {
 	}
 
 	/**
-	 * Returns the style variations defined by the theme.
+	 * Returns an array of all nested json files within a given directory.
+	 * 
+	 * @since 5.8.0
 	 *
-	 * @since 6.0.0
+	 * @param dir $dir The directory to recursively iterate and list files of.
+	 * @return array The merged array.
+	 */
+	private static function recursively_iterate_JSON( $dir ) {
+		$nested_files      = new RecursiveIteratorIterator( new RecursiveDirectoryIterator( $dir ) );
+		$nested_json_files = iterator_to_array( new RegexIterator( $nested_files, '/^.+\.json$/i', RecursiveRegexIterator::GET_MATCH ) );
+		return $nested_json_files;
+	}
+
+	/**
+	 * Returns the style variations defined by the theme (parent and child).
 	 *
 	 * @return array
 	 */
 	public static function get_style_variations() {
-		$variations     = array();
-		$base_directory = get_stylesheet_directory() . '/styles';
+		$variations         = array();
+		$base_directory     = get_stylesheet_directory() . '/styles';
+		$template_directory = get_template_directory() . '/styles';
 		if ( is_dir( $base_directory ) ) {
-			$nested_files      = new RecursiveIteratorIterator( new RecursiveDirectoryIterator( $base_directory ) );
-			$nested_html_files = iterator_to_array( new RegexIterator( $nested_files, '/^.+\.json$/i', RecursiveRegexIterator::GET_MATCH ) );
-			ksort( $nested_html_files );
-			foreach ( $nested_html_files as $path => $file ) {
+			$variation_files = static::recursively_iterate_JSON( $base_directory );
+			if ( $template_directory !== $base_directory && is_dir( $template_directory ) ) {
+				$variation_files_parent = static::recursively_iterate_JSON( $template_directory );
+				// If the child and parent variation file basename are the same, only include the child theme's.
+				foreach ( $variation_files_parent as $parent_path => $parent ) {
+					foreach ( $variation_files as $child_path => $child ) {
+						if ( basename( $parent_path ) === basename( $child_path ) ) {
+							unset( $variation_files_parent[ $parent_path ] );
+						}
+					}
+				}
+				$variation_files = array_merge( $variation_files, $variation_files_parent );
+			}
+			ksort( $variation_files );
+			foreach ( $variation_files as $path => $file ) {
 				$decoded_file = wp_json_file_decode( $path, array( 'associative' => true ) );
 				if ( is_array( $decoded_file ) ) {
 					$translated = static::translate( $decoded_file, wp_get_theme()->get( 'TextDomain' ) );
-					$variation  = ( new WP_Theme_JSON_Gutenberg( $translated ) )->get_raw_data();
+					$variation  = ( new WP_Theme_JSON( $translated ) )->get_raw_data();
 					if ( empty( $variation['title'] ) ) {
 						$variation['title'] = basename( $path, '.json' );
 					}
@@ -697,5 +721,4 @@ public static function get_style_variations() {
 		}
 		return $variations;
 	}
-
 }

lib/compat/wordpress-6.2/class-gutenberg-rest-global-styles-controller-6-2.php

@@ -252,4 +252,30 @@ public function get_theme_item( $request ) {
 
 		return $response;
 	}
+
+	/**
+	 * Returns the given theme global styles variations.
+	 *
+	 * @since 6.0.0
+	 * @since 6.2.0 Returns parent theme variations, if they exist.
+	 *
+	 * @param WP_REST_Request $request The request instance.
+	 *
+	 * @return WP_REST_Response|WP_Error
+	 */
+	public function get_theme_items( $request ) {
+		if ( get_stylesheet() !== $request['stylesheet'] ) {
+			// This endpoint only supports the active or parent theme for now.
+			return new WP_Error(
+				sprintf( '%s', $request['template'] ),
+				__( 'Theme not found.', 'gutenberg' ),
+				array( 'status' => 404 )
+			);
+		}
+
+		$variations = WP_Theme_JSON_Resolver_Gutenberg::get_style_variations();
+		$response   = rest_ensure_response( $variations );
+
+		return $response;
+	}
 }