diff -r 7b1b88e27a20 -r 48c4eec2b7e6 wp/wp-admin/includes/class-bulk-upgrader-skin.php
--- a/wp/wp-admin/includes/class-bulk-upgrader-skin.php	Thu Sep 29 08:06:27 2022 +0200
+++ b/wp/wp-admin/includes/class-bulk-upgrader-skin.php	Fri Sep 05 18:40:08 2025 +0200
@@ -16,13 +16,30 @@
  * @see WP_Upgrader_Skin
  */
 class Bulk_Upgrader_Skin extends WP_Upgrader_Skin {
+
+	/**
+	 * Whether the bulk update process has started.
+	 *
+	 * @since 3.0.0
+	 * @var bool
+	 */
 	public $in_loop = false;
+
 	/**
+	 * Stores an error message about the update.
+	 *
+	 * @since 3.0.0
 	 * @var string|false
 	 */
 	public $error = false;
 
 	/**
+	 * Constructor.
+	 *
+	 * Sets up the generic skin for the Bulk Upgrader classes.
+	 *
+	 * @since 3.0.0
+	 *
 	 * @param array $args
 	 */
 	public function __construct( $args = array() ) {
@@ -36,6 +53,9 @@
 	}
 
 	/**
+	 * Sets up the strings used in the update process.
+	 *
+	 * @since 3.0.0
 	 */
 	public function add_strings() {
 		$this->upgrader->strings['skin_upgrade_start'] = __( 'The update process is starting. This process may take a while on some hosts, so please be patient.' );
@@ -49,6 +69,9 @@
 	}
 
 	/**
+	 * Displays a message about the update.
+	 *
+	 * @since 3.0.0
 	 * @since 5.9.0 Renamed `$string` (a PHP reserved keyword) to `$feedback` for PHP 8 named parameter support.
 	 *
 	 * @param string $feedback Message data.
@@ -59,7 +82,7 @@
 			$feedback = $this->upgrader->strings[ $feedback ];
 		}
 
-		if ( strpos( $feedback, '%' ) !== false ) {
+		if ( str_contains( $feedback, '%' ) ) {
 			if ( $args ) {
 				$args     = array_map( 'strip_tags', $args );
 				$args     = array_map( 'esc_html', $args );
@@ -77,18 +100,27 @@
 	}
 
 	/**
+	 * Displays the header before the update process.
+	 *
+	 * @since 3.0.0
 	 */
 	public function header() {
-		// Nothing, This will be displayed within a iframe.
+		// Nothing. This will be displayed within an iframe.
 	}
 
 	/**
+	 * Displays the footer following the update process.
+	 *
+	 * @since 3.0.0
 	 */
 	public function footer() {
-		// Nothing, This will be displayed within a iframe.
+		// Nothing. This will be displayed within an iframe.
 	}
 
 	/**
+	 * Displays an error message about the update.
+	 *
+	 * @since 3.0.0
 	 * @since 5.9.0 Renamed `$error` to `$errors` for PHP 8 named parameter support.
 	 *
 	 * @param string|WP_Error $errors Errors.
@@ -113,40 +145,60 @@
 	}
 
 	/**
+	 * Displays the header before the bulk update process.
+	 *
+	 * @since 3.0.0
 	 */
 	public function bulk_header() {
 		$this->feedback( 'skin_upgrade_start' );
 	}
 
 	/**
+	 * Displays the footer following the bulk update process.
+	 *
+	 * @since 3.0.0
 	 */
 	public function bulk_footer() {
 		$this->feedback( 'skin_upgrade_end' );
 	}
 
 	/**
+	 * Performs an action before a bulk update.
+	 *
+	 * @since 3.0.0
+	 *
 	 * @param string $title
 	 */
 	public function before( $title = '' ) {
 		$this->in_loop = true;
 		printf( '<h2>' . $this->upgrader->strings['skin_before_update_header'] . ' <span class="spinner waiting-' . $this->upgrader->update_current . '"></span></h2>', $title, $this->upgrader->update_current, $this->upgrader->update_count );
 		echo '<script type="text/javascript">jQuery(\'.waiting-' . esc_js( $this->upgrader->update_current ) . '\').css("display", "inline-block");</script>';
-		// This progress messages div gets moved via JavaScript when clicking on "Show details.".
+		// This progress messages div gets moved via JavaScript when clicking on "More details.".
 		echo '<div class="update-messages hide-if-js" id="progress-' . esc_attr( $this->upgrader->update_current ) . '"><p>';
 		$this->flush_output();
 	}
 
 	/**
+	 * Performs an action following a bulk update.
+	 *
+	 * @since 3.0.0
+	 *
 	 * @param string $title
 	 */
 	public function after( $title = '' ) {
 		echo '</p></div>';
 		if ( $this->error || ! $this->result ) {
 			if ( $this->error ) {
-				echo '<div class="error"><p>' . sprintf( $this->upgrader->strings['skin_update_failed_error'], $title, '<strong>' . $this->error . '</strong>' ) . '</p></div>';
+				$after_error_message = sprintf( $this->upgrader->strings['skin_update_failed_error'], $title, '<strong>' . $this->error . '</strong>' );
 			} else {
-				echo '<div class="error"><p>' . sprintf( $this->upgrader->strings['skin_update_failed'], $title ) . '</p></div>';
+				$after_error_message = sprintf( $this->upgrader->strings['skin_update_failed'], $title );
 			}
+			wp_admin_notice(
+				$after_error_message,
+				array(
+					'additional_classes' => array( 'error' ),
+				)
+			);
 
 			echo '<script type="text/javascript">jQuery(\'#progress-' . esc_js( $this->upgrader->update_current ) . '\').show();</script>';
 		}
@@ -154,7 +206,7 @@
 			if ( ! $this->error ) {
 				echo '<div class="updated js-update-details" data-update-details="progress-' . esc_attr( $this->upgrader->update_current ) . '">' .
 					'<p>' . sprintf( $this->upgrader->strings['skin_update_successful'], $title ) .
-					' <button type="button" class="hide-if-no-js button-link js-update-details-toggle" aria-expanded="false">' . __( 'Show details.' ) . '</button>' .
+					' <button type="button" class="hide-if-no-js button-link js-update-details-toggle" aria-expanded="false">' . __( 'More details.' ) . '<span class="dashicons dashicons-arrow-down" aria-hidden="true"></span></button>' .
 					'</p></div>';
 			}
 
@@ -166,6 +218,9 @@
 	}
 
 	/**
+	 * Resets the properties used in the update process.
+	 *
+	 * @since 3.0.0
 	 */
 	public function reset() {
 		$this->in_loop = false;
@@ -173,6 +228,9 @@
 	}
 
 	/**
+	 * Flushes all output buffers.
+	 *
+	 * @since 3.0.0
 	 */
 	public function flush_output() {
 		wp_ob_end_flush_all();