first commit

wp/wp-content/plugins/wordpress-seo/src/integrations/front-end/handle-404.php

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+<?php
+
+namespace Yoast\WP\SEO\Integrations\Front_End;
+
+use Yoast\WP\SEO\Conditionals\Front_End_Conditional;
+use Yoast\WP\SEO\Integrations\Integration_Interface;
+use Yoast\WP\SEO\Wrappers\WP_Query_Wrapper;
+
+/**
+ * Handles intercepting requests.
+ */
+class Handle_404 implements Integration_Interface {
+
+	/**
+	 * The WP Query wrapper.
+	 *
+	 * @var WP_Query_Wrapper
+	 */
+	private $query_wrapper;
+
+	/**
+	 * Returns the conditionals based in which this loadable should be active.
+	 *
+	 * @return array
+	 */
+	public static function get_conditionals() {
+		return [ Front_End_Conditional::class ];
+	}
+
+	/**
+	 * Initializes the integration.
+	 *
+	 * This is the place to register hooks and filters.
+	 *
+	 * @return void
+	 */
+	public function register_hooks() {
+		\add_filter( 'pre_handle_404', [ $this, 'handle_404' ] );
+	}
+
+	/**
+	 * Handle_404 constructor.
+	 *
+	 * @codeCoverageIgnore Handles dependencies.
+	 *
+	 * @param WP_Query_Wrapper $query_wrapper The query wrapper.
+	 */
+	public function __construct( WP_Query_Wrapper $query_wrapper ) {
+		$this->query_wrapper = $query_wrapper;
+	}
+
+	/**
+	 * Handles the 404 status code.
+	 *
+	 * @param bool $handled Whether we've handled the request.
+	 *
+	 * @return bool True if it's 404.
+	 */
+	public function handle_404( $handled ) {
+		if ( ! $this->is_feed_404() ) {
+			return $handled;
+		}
+
+		$this->set_404();
+		$this->set_headers();
+
+		\add_filter( 'old_slug_redirect_url', '__return_false' );
+		\add_filter( 'redirect_canonical', '__return_false' );
+
+		return true;
+	}
+
+	/**
+	 * If there are no posts in a feed, make it 404 instead of sending an empty RSS feed.
+	 *
+	 * @return bool True if it's 404.
+	 */
+	protected function is_feed_404() {
+		if ( ! \is_feed() ) {
+			return false;
+		}
+
+		$wp_query = $this->query_wrapper->get_query();
+
+		// Don't 404 if the query contains post(s) or an object.
+		if ( $wp_query->posts || $wp_query->get_queried_object() ) {
+			return false;
+		}
+
+		// Don't 404 if it isn't archive or singular.
+		if ( ! $wp_query->is_archive() && ! $wp_query->is_singular() ) {
+			return false;
+		}
+
+		return true;
+	}
+
+	/**
+	 * Sets the 404 status code.
+	 */
+	protected function set_404() {
+		$wp_query          = $this->query_wrapper->get_query();
+		$wp_query->is_feed = false;
+		$wp_query->set_404();
+		$this->query_wrapper->set_query( $wp_query );
+	}
+
+	/**
+	 * Sets the headers for http.
+	 *
+	 * @codeCoverageIgnore
+	 */
+	protected function set_headers() {
+		// Overwrite Content-Type header.
+		if ( ! \headers_sent() ) {
+			\header( 'Content-Type: ' . \get_option( 'html_type' ) . '; charset=' . \get_option( 'blog_charset' ) );
+		}
+
+		\status_header( 404 );
+		\nocache_headers();
+	}
+}