Spring Security Inconsistent ReactiveOAuth2UserService in OAuth2LoginSpec

Describe the bug The way to configure a ReactiveOAuth2UserService<OAuth2UserRequest, OAuth2User> in OAuth2LoginSpec is inconsistent.

More specifically: - OAuth2LoginReactiveAuthenticationManager constructor is called over getOauth2UserService() which search for a bean of type ReactiveOAuth2UserService, else fallback on DefaultReactiveOAuth2UserService - OidcReactiveOAuth2UserService is instanciated by its default constructor, without relying on getOauth2UserService()

        private ReactiveAuthenticationManager createDefault() {
            [...]
            OAuth2LoginReactiveAuthenticationManager oauth2Manager = new OAuth2LoginReactiveAuthenticationManager(
                    client, getOauth2UserService());

        private ReactiveOAuth2UserService<OidcUserRequest, OidcUser> getOidcUserService() {
            ResolvableType type = ResolvableType.forClassWithGenerics(ReactiveOAuth2UserService.class,
                    OidcUserRequest.class, OidcUser.class);
            ReactiveOAuth2UserService<OidcUserRequest, OidcUser> bean = getBeanOrNull(type);
            if (bean != null) {
                return bean;
            }
            return new OidcReactiveOAuth2UserService();
        }

This leads to inconsistent ReactiveOAuth2UserService through the components created by OAuth2LoginSpec.

To Reproduce

@EnableWebFluxSecurity
@Import({

        CustomOAuth2UserService.class,

})
@Slf4j
@SpringBootApplication(scanBasePackages = "none")
public class InconsistentOAuth2UserDetailsServiceApp {
    public static class CustomOAuth2UserService extends DefaultOAuth2UserService {

    }

    @Bean
    public SecurityWebFilterChain configureUi(ServerHttpSecurity http) {

        return http.build();
    }

    public static void main(String[] args) {
        SpringApplication.run(InconsistentOAuth2UserDetailsServiceApp.class);
    }

}

Expected behavior Given a bean of type ReactiveOAuth2UserService, it should be injected to all components needed one, especially OidcReactiveOAuth2UserService, as it is done for OAuth2LoginReactiveAuthenticationManager

Comment From: blacelle

Workaround: provide a OidcReactiveOAuth2UserService bean with relevant ReactiveOAuth2UserService:

    @Bean
    public OidcReactiveOAuth2UserService oidcReactiveOAuth2UserService(
            ReactiveOAuth2UserService<OAuth2UserRequest, OAuth2User> oauth2UserService) {
        OidcReactiveOAuth2UserService oidcReactiveOAuth2UserService = new OidcReactiveOAuth2UserService();

        oidcReactiveOAuth2UserService.setOauth2UserService(oauth2UserService);

        return oidcReactiveOAuth2UserService;
    }