--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/wp/wp-includes/class-wp-theme-json-schema.php	Tue Sep 27 16:37:53 2022 +0200
@@ -0,0 +1,152 @@
+<?php
+/**
+ * WP_Theme_JSON_Schema class
+ *
+ * @package WordPress
+ * @subpackage Theme
+ * @since 5.9.0
+ */
+
+/**
+ * Class that migrates a given theme.json structure to the latest schema.
+ *
+ * This class is for internal core usage and is not supposed to be used by extenders (plugins and/or themes).
+ * This is a low-level API that may need to do breaking changes. Please,
+ * use get_global_settings, get_global_styles, and get_global_stylesheet instead.
+ *
+ * @since 5.9.0
+ * @access private
+ */
+class WP_Theme_JSON_Schema {
+
+	/**
+	 * Maps old properties to their new location within the schema's settings.
+	 * This will be applied at both the defaults and individual block levels.
+	 */
+	const V1_TO_V2_RENAMED_PATHS = array(
+		'border.customRadius'         => 'border.radius',
+		'spacing.customMargin'        => 'spacing.margin',
+		'spacing.customPadding'       => 'spacing.padding',
+		'typography.customLineHeight' => 'typography.lineHeight',
+	);
+
+	/**
+	 * Function that migrates a given theme.json structure to the last version.
+	 *
+	 * @since 5.9.0
+	 *
+	 * @param array $theme_json The structure to migrate.
+	 *
+	 * @return array The structure in the last version.
+	 */
+	public static function migrate( $theme_json ) {
+		if ( ! isset( $theme_json['version'] ) ) {
+			$theme_json = array(
+				'version' => WP_Theme_JSON::LATEST_SCHEMA,
+			);
+		}
+
+		if ( 1 === $theme_json['version'] ) {
+			$theme_json = self::migrate_v1_to_v2( $theme_json );
+		}
+
+		return $theme_json;
+	}
+
+	/**
+	 * Removes the custom prefixes for a few properties
+	 * that were part of v1:
+	 *
+	 * 'border.customRadius'         => 'border.radius',
+	 * 'spacing.customMargin'        => 'spacing.margin',
+	 * 'spacing.customPadding'       => 'spacing.padding',
+	 * 'typography.customLineHeight' => 'typography.lineHeight',
+	 *
+	 * @since 5.9.0
+	 *
+	 * @param array $old Data to migrate.
+	 *
+	 * @return array Data without the custom prefixes.
+	 */
+	private static function migrate_v1_to_v2( $old ) {
+		// Copy everything.
+		$new = $old;
+
+		// Overwrite the things that changed.
+		if ( isset( $old['settings'] ) ) {
+			$new['settings'] = self::rename_paths( $old['settings'], self::V1_TO_V2_RENAMED_PATHS );
+		}
+
+		// Set the new version.
+		$new['version'] = 2;
+
+		return $new;
+	}
+
+	/**
+	 * Processes the settings subtree.
+	 *
+	 * @since 5.9.0
+	 *
+	 * @param array $settings        Array to process.
+	 * @param array $paths_to_rename Paths to rename.
+	 *
+	 * @return array The settings in the new format.
+	 */
+	private static function rename_paths( $settings, $paths_to_rename ) {
+		$new_settings = $settings;
+
+		// Process any renamed/moved paths within default settings.
+		self::rename_settings( $new_settings, $paths_to_rename );
+
+		// Process individual block settings.
+		if ( isset( $new_settings['blocks'] ) && is_array( $new_settings['blocks'] ) ) {
+			foreach ( $new_settings['blocks'] as &$block_settings ) {
+				self::rename_settings( $block_settings, $paths_to_rename );
+			}
+		}
+
+		return $new_settings;
+	}
+
+	/**
+	 * Processes a settings array, renaming or moving properties.
+	 *
+	 * @since 5.9.0
+	 *
+	 * @param array $settings        Reference to settings either defaults or an individual block's.
+	 * @param array $paths_to_rename Paths to rename.
+	 */
+	private static function rename_settings( &$settings, $paths_to_rename ) {
+		foreach ( $paths_to_rename as $original => $renamed ) {
+			$original_path = explode( '.', $original );
+			$renamed_path  = explode( '.', $renamed );
+			$current_value = _wp_array_get( $settings, $original_path, null );
+
+			if ( null !== $current_value ) {
+				_wp_array_set( $settings, $renamed_path, $current_value );
+				self::unset_setting_by_path( $settings, $original_path );
+			}
+		}
+	}
+
+	/**
+	 * Removes a property from within the provided settings by its path.
+	 *
+	 * @since 5.9.0
+	 *
+	 * @param array $settings Reference to the current settings array.
+	 * @param array $path Path to the property to be removed.
+	 *
+	 * @return void
+	 */
+	private static function unset_setting_by_path( &$settings, $path ) {
+		$tmp_settings = &$settings; // phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable
+		$last_key     = array_pop( $path );
+		foreach ( $path as $key ) {
+			$tmp_settings = &$tmp_settings[ $key ];
+		}
+
+		unset( $tmp_settings[ $last_key ] );
+	}
+}