Ticket #15770: 15770.2.diff

wp-includes/class-wp.php

@@ -474 +474 @@
         function handle_404() {
                 global $wp_query;
 
-                if ( !is_admin() && ( 0 == count( $wp_query->posts ) ) && !is_404() && !is_robots() && !is_search() && !is_home() ) {
+                // If we've already issued a 404, bail.
+                if ( is_404() )
+                        return;
+
+                // Never 404 for the admin, robots, or if we found posts.
+                if ( is_admin() || is_robots() || $wp_query->posts ) {
+                        status_header( 200 );
+                        return;
+                }
+
+                // We will 404 for paged queries, as no posts were found.
+                if ( ! is_paged() ) {
+
                         // Don't 404 for these queries if they matched an object.
-                        if ( ( is_tag() || is_category() || is_tax() || is_author() || is_post_type_archive() ) && $wp_query->get_queried_object() && !is_paged() ) {
-                                if ( !is_404() )
-                                        status_header( 200 );
+                        if ( ( is_tag() || is_category() || is_tax() || is_author() || is_post_type_archive() ) && $wp_query->get_queried_object() ) {
+                                status_header( 200 );
                                 return;
                         }
-                        $wp_query->set_404();
-                        status_header( 404 );
-                        nocache_headers();
-                } elseif ( !is_404() ) {
-                        status_header( 200 );
+
+                        // Don't 404 for these queries either.
+                        if ( is_home() || is_search() ) {
+                                status_header( 200 );
+                                return;
+                        }
                 }
+
+                // Guess it's time to 404.
+                $wp_query->set_404();
+                status_header( 404 );
+                nocache_headers();
         }
 
         /**