Ticket #41358: end-rest-api-connection-41358.diff

wp-includes/rest-api.php

@@ -269 +269 @@
                 $route = '/';
         }
         $server->serve_request( $route );
+        $server->finish_request();
 
         // We're done.
         die();

wp-includes/rest-api/class-wp-rest-server.php

@@ -414 +414 @@
         }
 
         /**
+         * Handles finishing an API request.
+         *
+         * Closes connections, where possible, so the response is sent as soon as possible
+         * and is not slowed down by functions during shutdown.
+         *
+         * @access public
+         */
+        public function finish_request() {
+                if ( is_callable( 'fastcgi_finish_request' ) ) {
+                        // This function is available on nginx and is the cleanest solution.
+                        fastcgi_finish_request();
+
+                } elseif ( ! headers_sent() ) {
+                        // For apache, we can send some headers to end the connection early.
+                        header( 'Content-Length: ' . ob_get_length() );
+                        header( 'Connection: close' );
+                        ob_end_flush();
+                        flush();
+                }
+        }
+
+        /**
          * Converts a response to data to send.
          *
          * @since 4.4.0