gateway MVC - Multi-part + query string not working

Describe the bug

With spring cloud gateway mvc 2023.0.0 when we perform an post request with multi part and query string, the query string was loose.

Exemple with an test server on port 9008 and a gateway on port 9007
if i point on the server directly :


if i use the gateway :

Sample
http-interceptor : (it's juste a test server to print the query param)

public class MainStandAlone {

    public static void main(String[] args) throws IOException {

        ThreadPoolExecutor threadPoolExecutor = (ThreadPoolExecutor) Executors.newFixedThreadPool(10);

        HttpServer server = HttpServer.create(new InetSocketAddress("localhost", 9008), 0);
          server.createContext("/", exchange -> {
            System.out.println(exchange.getRequestURI());

            exchange.getResponseBody().write("OK".getBytes(StandardCharsets.UTF_8));
            exchange.sendResponseHeaders(200, "OK".length());
            exchange.getResponseBody().flush();
            exchange.getResponseBody().close();
        });
        server.setExecutor(threadPoolExecutor);
        server.start();
        System.out.println(" Server started on port 9008");
    }
}

gateway : (spring initializr)

@SpringBootApplication
public class DemoApplication {

	public static void main(String[] args) {
		SpringApplication.run(DemoApplication.class, args);
	}

	@Configuration
	public static class GatewayConfiguration {

		@Bean
		public RouterFunction<ServerResponse> routerFunction() {
			return route()
					.POST("/test", http("http://localhost:9008"))
					.build();
		}
	}
}

EDIT:

Moreover the header Content-Length are delete by the gateway

Start with the MVC gateway route in the sample GatewayConfiguration and reproduce the POST to /test using the provided multipart request and query string, comparing it with the direct server request. Trace the forwarded request and verify that the query string and Content-Length are preserved; done means the downstream server receives both correctly.