--- a/wp/wp-admin/includes/class-theme-upgrader.php	Tue Dec 15 15:52:01 2020 +0100
+++ b/wp/wp-admin/includes/class-theme-upgrader.php	Wed Sep 21 18:19:35 2022 +0200
@@ -270,16 +270,7 @@
 		wp_clean_themes_cache( $parsed_args['clear_update_cache'] );
 
 		if ( $parsed_args['overwrite_package'] ) {
-			/**
-			 * Fires when the upgrader has successfully overwritten a currently installed
-			 * plugin or theme with an uploaded zip package.
-			 *
-			 * @since 5.5.0
-			 *
-			 * @param string  $package        The package file.
-			 * @param array   $new_theme_data The new theme data.
-			 * @param string  $package_type   The package type (plugin or theme).
-			 */
+			/** This action is documented in wp-admin/includes/class-plugin-upgrader.php */
 			do_action( 'upgrader_overwrote_package', $package, $this->new_theme_data, 'theme' );
 		}
 
@@ -510,21 +501,20 @@
 	}
 
 	/**
-	 * Check that the package source contains a valid theme.
+	 * Checks that the package source contains a valid theme.
 	 *
 	 * Hooked to the {@see 'upgrader_source_selection'} filter by Theme_Upgrader::install().
-	 * It will return an error if the theme doesn't have style.css or index.php
-	 * files.
 	 *
 	 * @since 3.3.0
 	 *
 	 * @global WP_Filesystem_Base $wp_filesystem WordPress filesystem subclass.
+	 * @global string             $wp_version    The WordPress version string.
 	 *
-	 * @param string $source The full path to the package source.
-	 * @return string|WP_Error The source or a WP_Error.
+	 * @param string $source The path to the downloaded package source.
+	 * @return string|WP_Error The source as passed, or a WP_Error object on failure.
 	 */
 	public function check_package( $source ) {
-		global $wp_filesystem;
+		global $wp_filesystem, $wp_version;
 
 		$this->new_theme_data = array();
 
@@ -606,7 +596,7 @@
 			$error = sprintf(
 				/* translators: 1: Current WordPress version, 2: Version required by the uploaded theme. */
 				__( 'Your WordPress version is %1$s, however the uploaded theme requires %2$s.' ),
-				$GLOBALS['wp_version'],
+				$wp_version,
 				$requires_wp
 			);