Ticket #50643: 50643.3.diff

src/wp-includes/sitemaps.php

@@ -17 +17 @@
  *
  * @global WP_Sitemaps $wp_sitemaps Global Core Sitemaps instance.
  *
- * @return WP_Sitemaps|null Sitemaps instance, or null if sitemaps are disabled.
+ * @return WP_Sitemaps Sitemaps instance.
  */
 function wp_sitemaps_get_server() {
         global $wp_sitemaps;
 
         $is_enabled = (bool) get_option( 'blog_public' );
 
-        /**
-         * Filters whether XML Sitemaps are enabled or not.
-         *
-         * @since 5.5.0
-         *
-         * @param bool $is_enabled Whether XML Sitemaps are enabled or not. Defaults to true for public sites.
-         */
-        $is_enabled = (bool) apply_filters( 'wp_sitemaps_enabled', $is_enabled );
-
-        if ( ! $is_enabled ) {
-                return null;
-        }
-
         // If there isn't a global instance, set and bootstrap the sitemaps system.
         if ( empty( $wp_sitemaps ) ) {
                 $wp_sitemaps = new WP_Sitemaps();

src/wp-includes/sitemaps/class-wp-sitemaps.php

@@ -56 +56 @@
         /**
          * Initiates all sitemap functionality.
          *
+         * If sitemaps are disabled, only the rewrite rules will be registered
+         * by this method, in order to properly send 404s.
+         *
          * @since 5.5.0
          */
         public function init() {
                 // These will all fire on the init hook.
                 $this->register_rewrites();
+
+                add_action( 'template_redirect', array( $this, 'render_sitemaps' ) );
+
+                if ( ! $this->sitemaps_enabled() ) {
+                        return;
+                }
+
                 $this->register_sitemaps();
 
                 // Add additional action callbacks.
-                add_action( 'template_redirect', array( $this, 'render_sitemaps' ) );
                 add_filter( 'pre_handle_404', array( $this, 'redirect_sitemapxml' ), 10, 2 );
                 add_filter( 'robots_txt', array( $this, 'add_robots' ), 0, 2 );
         }
 
+        /**
+         * Determines whether sitemaps are enabled or not.
+         *
+         * @since 5.5.0
+         *
+         * @return bool Whether sitemaps are enabled.
+         */
+        public function sitemaps_enabled() {
+                $is_enabled = (bool) get_option( 'blog_public' );
+
+                /**
+                 * Filters whether XML Sitemaps are enabled or not.
+                 *
+                 * When XML Sitemaps are disabled via this filter, rewrite rules are still in place to ensure a 404 is returned.
+                 * @see WP_Sitemaps->register_rewrites()
+                 *
+                 * @since 5.5.0
+                 *
+                 * @param bool $is_enabled Whether XML Sitemaps are enabled or not. Defaults to true for public sites.
+                 */
+                return (bool) apply_filters( 'wp_sitemaps_enabled', $is_enabled );
+        }
+
         /**
          * Registers and sets up the functionality for all supported sitemaps.
          *
@@ -143 +175 @@
          * @global WP_Query $wp_query WordPress Query object.
          */
         public function render_sitemaps() {
+                /* @var WP_Query $wp_query */
                 global $wp_query;
 
                 $sitemap         = sanitize_text_field( get_query_var( 'sitemap' ) );
@@ -155 +188 @@
                         return;
                 }
 
+                if ( ! $this->sitemaps_enabled() ) {
+                        $wp_query->set_404();
+                        status_header( 404 );
+                        return;
+                }
+
                 // Render stylesheet if this is stylesheet route.
                 if ( $stylesheet_type ) {
                         $stylesheet = new WP_Sitemaps_Stylesheet();
@@ -186 +225 @@
                 // Force a 404 and bail early if no URLs are present.
                 if ( empty( $url_list ) ) {
                         $wp_query->set_404();
+                        status_header( 404 );
                         return;
                 }