WP_Widget_Custom_HTML::widget( array $args, array $instance )

	public function widget( $args, $instance ) {
		global $post;

		// Override global $post so filters (and shortcodes) apply in a consistent context.
		$original_post = $post;
		if ( is_singular() ) {
			// Make sure post is always the queried object on singular queries (not from another sub-query that failed to clean up the global $post).
			$post = get_queried_object();
		} else {
			// Nullify the $post global during widget rendering to prevent shortcodes from running with the unexpected context on archive queries.
			$post = null;
		}

		// Prevent dumping out all attachments from the media library.
		add_filter( 'shortcode_atts_gallery', array( $this, '_filter_gallery_shortcode_attrs' ) );

		$instance = array_merge( $this->default_instance, $instance );

		/** This filter is documented in wp-includes/widgets/class-wp-widget-pages.php */
		$title = apply_filters( 'widget_title', $instance['title'], $instance, $this->id_base );

		// Prepare instance data that looks like a normal Text widget.
		$simulated_text_widget_instance = array_merge( $instance, array(
			'text' => isset( $instance['content'] ) ? $instance['content'] : '',
			'filter' => false, // Because wpautop is not applied.
			'visual' => false, // Because it wasn't created in TinyMCE.
		) );
		unset( $simulated_text_widget_instance['content'] ); // Was moved to 'text' prop.

		/** This filter is documented in wp-includes/widgets/class-wp-widget-text.php */
		$content = apply_filters( 'widget_text', $instance['content'], $simulated_text_widget_instance, $this );

		/**
		 * Filters the content of the Custom HTML widget.
		 *
		 * @since WP-4.8.1
		 *
		 * @param string                $content  The widget content.
		 * @param array                 $instance Array of settings for the current widget.
		 * @param WP_Widget_Custom_HTML $this     Current Custom HTML widget instance.
		 */
		$content = apply_filters( 'widget_custom_html_content', $content, $instance, $this );

		// Restore post global.
		$post = $original_post;
		remove_filter( 'shortcode_atts_gallery', array( $this, '_filter_gallery_shortcode_attrs' ) );

		// Inject the Text widget's container class name alongside this widget's class name for theme styling compatibility.
		$args['before_widget'] = preg_replace( '/(?<=\sclass=["\'])/', 'widget_text ', $args['before_widget'] );

		echo $args['before_widget'];
		if ( ! empty( $title ) ) {
			echo $args['before_title'] . $title . $args['after_title'];
		}
		echo '<div class="textwidget custom-html-widget">'; // The textwidget class is for theme styling compatibility.
		echo $content;
		echo '</div>';
		echo $args['after_widget'];
	}