diff -r 490d5cc509ed -r cf61fcea0001 wp/wp-includes/widgets/class-wp-widget-calendar.php
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/wp/wp-includes/widgets/class-wp-widget-calendar.php	Mon Oct 14 17:39:30 2019 +0200
@@ -0,0 +1,105 @@
+<?php
+/**
+ * Widget API: WP_Widget_Calendar class
+ *
+ * @package WordPress
+ * @subpackage Widgets
+ * @since 4.4.0
+ */
+
+/**
+ * Core class used to implement the Calendar widget.
+ *
+ * @since 2.8.0
+ *
+ * @see WP_Widget
+ */
+class WP_Widget_Calendar extends WP_Widget {
+	/**
+	 * Ensure that the ID attribute only appears in the markup once
+	 *
+	 * @since 4.4.0
+	 *
+	 * @static
+	 * @var int
+	 */
+	private static $instance = 0;
+
+	/**
+	 * Sets up a new Calendar widget instance.
+	 *
+	 * @since 2.8.0
+	 */
+	public function __construct() {
+		$widget_ops = array(
+			'classname' => 'widget_calendar',
+			'description' => __( 'A calendar of your site&#8217;s Posts.' ),
+			'customize_selective_refresh' => true,
+		);
+		parent::__construct( 'calendar', __( 'Calendar' ), $widget_ops );
+	}
+
+	/**
+	 * Outputs the content for the current Calendar widget instance.
+	 *
+	 * @since 2.8.0
+	 *
+	 * @param array $args     Display arguments including 'before_title', 'after_title',
+	 *                        'before_widget', and 'after_widget'.
+	 * @param array $instance The settings for the particular instance of the widget.
+	 */
+	public function widget( $args, $instance ) {
+		$title = ! empty( $instance['title'] ) ? $instance['title'] : '';
+
+		/** This filter is documented in wp-includes/widgets/class-wp-widget-pages.php */
+		$title = apply_filters( 'widget_title', $title, $instance, $this->id_base );
+
+		echo $args['before_widget'];
+		if ( $title ) {
+			echo $args['before_title'] . $title . $args['after_title'];
+		}
+		if ( 0 === self::$instance ) {
+			echo '<div id="calendar_wrap" class="calendar_wrap">';
+		} else {
+			echo '<div class="calendar_wrap">';
+		}
+		get_calendar();
+		echo '</div>';
+		echo $args['after_widget'];
+
+		self::$instance++;
+	}
+
+	/**
+	 * Handles updating settings for the current Calendar widget instance.
+	 *
+	 * @since 2.8.0
+	 *
+	 * @param array $new_instance New settings for this instance as input by the user via
+	 *                            WP_Widget::form().
+	 * @param array $old_instance Old settings for this instance.
+	 * @return array Updated settings to save.
+	 */
+	public function update( $new_instance, $old_instance ) {
+		$instance = $old_instance;
+		$instance['title'] = sanitize_text_field( $new_instance['title'] );
+
+		return $instance;
+	}
+
+	/**
+	 * Outputs the settings form for the Calendar widget.
+	 *
+	 * @since 2.8.0
+	 *
+	 * @param array $instance Current settings.
+	 */
+	public function form( $instance ) {
+		$instance = wp_parse_args( (array) $instance, array( 'title' => '' ) );
+		$title = sanitize_text_field( $instance['title'] );
+		?>
+		<p><label for="<?php echo $this->get_field_id('title'); ?>"><?php _e('Title:'); ?></label>
+		<input class="widefat" id="<?php echo $this->get_field_id('title'); ?>" name="<?php echo $this->get_field_name('title'); ?>" type="text" value="<?php echo esc_attr($title); ?>" /></p>
+		<?php
+	}
+}