DefaultAsyncAutoConfiguration override a implicit AsyncTaskExecutor

problem

spring-aop has a implicit rule for determining default AsyncExecutor when there`s no AsyncConfigurer existed

See AsyncExecutionAspectSupport.java#L227

DefaultAsyncAutoConfiguration will override it in the above case

@Configuration
@ConditionalOnMissingBean(AsyncConfigurer.class)
  static class DefaultTracedAsyncConfigurerSupport extends AsyncConfigurerSupport {
    @Autowired
    @Lazy
    private Tracer tracer;
    @Override
    public Executor getAsyncExecutor() {
      return new TracedExecutor(new SimpleAsyncTaskExecutor(), tracer);
    }
  }

version

java version "1.8.0_131"
spring-aop 4.3.11
opentracing-spring-cloud-core latest

Start with AsyncExecutionAspectSupport.java at the linked line, then inspect DefaultAsyncAutoConfiguration and its DefaultTracedAsyncConfigurerSupport configuration. Reproduce the case with spring-aop 4.3.11 and opentracing-spring-cloud-core, and verify that the framework's implicit AsyncTaskExecutor selection is preserved when no AsyncConfigurer exists.