Fix Jetty 10+ test failure related to empty path handling

See gh-27424

spring-web/src/test/java/org/springframework/http/server/reactive/ErrorHandlerIntegrationTests.java

@@ -27,6 +27,7 @@ import org.springframework.web.client.ResponseErrorHandler;
 import org.springframework.web.client.RestTemplate;
 import org.springframework.web.testfixture.http.server.reactive.bootstrap.AbstractHttpHandlerIntegrationTests;
 import org.springframework.web.testfixture.http.server.reactive.bootstrap.HttpServer;
+import org.springframework.web.testfixture.http.server.reactive.bootstrap.JettyHttpServer;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -80,7 +81,14 @@ class ErrorHandlerIntegrationTests extends AbstractHttpHandlerIntegrationTests {
 		URI url = new URI("http://localhost:" + port + "//");
 		ResponseEntity<String> response = restTemplate.getForEntity(url, String.class);
 
-		assertThat(response.getStatusCode()).isEqualTo(HttpStatus.OK);
+		// Jetty 10+ rejects empty path segments, see https://github.com/eclipse/jetty.project/issues/6302,
+		// but an application can apply CompactPathRule via RewriteHandler:
+		// https://www.eclipse.org/jetty/documentation/jetty-11/programming_guide.php
+
+		HttpStatus expectedStatus =
+				(httpServer instanceof JettyHttpServer ? HttpStatus.BAD_REQUEST : HttpStatus.OK);
+
+		assertThat(response.getStatusCode()).isEqualTo(expectedStatus);
 	}