Serving plain text file using a default label is not working in Finchley M9

Using a config server at version Finchley.M9 with the following properties

spring:
  application:
    name: testapp
  profiles:
    active: native
  cloud:
    config:
      server:
        default-label: default-label-test

and config directory layout src/main/resources/config/default-label-test/default-label-nginx.conf

When I request the contents of default-label-nginx.conf with a request
curl http://localhost:9999/testapp/native/default-label-nginx.conf\?useDefaultLabel, the mapped controller is https://github.com/spring-cloud/spring-cloud-config/blob/master/spring-cloud-config-server/src/main/java/org/springframework/cloud/config/server/environment/EnvironmentController.java#L99
but should be
https://github.com/spring-cloud/spring-cloud-config/blob/master/spring-cloud-config-server/src/main/java/org/springframework/cloud/config/server/resource/ResourceController.java#L81

Using Edgware.SR2 the correct controller method is mapped

@snicoll mentioned that request mapping has changed in Boot 2, see https://github.com/spring-projects/spring-boot/wiki/Spring-Boot-2.0-Migration-Guide#spring-mvc-path-matching-default-behavior-change

Reproduce the request with the Finchley.M9 configuration and inspect the mappings in EnvironmentController.java and ResourceController.java at the referenced lines. Compare the request-mapping behavior with the Boot 2 path-matching migration note. Done means the plain-text file request using useDefaultLabel reaches the resource endpoint and returns the file from the configured default-label directory.