Bug Description

In RocketMQMessageListenerBeanPostProcessor.buildEnhancer(), the composed AnnotationEnhancer lambda correctly accumulates modified attributes through all registered enhancer beans into newAttrs, but then returns the original attrs instead of newAttrs.

This makes every registered AnnotationEnhancer bean a silent no-op — attribute modifications are computed but immediately discarded.

Affected Version

2.3.6 (rocketmq-v5-client-spring-boot)

Root Cause

RocketMQMessageListenerBeanPostProcessor.buildEnhancer():

this.enhancer = (attrs, element) -> {
    Map<String, Object> newAttrs = attrs;
    for (AnnotationEnhancer enh : enhancers) {
        newAttrs = enh.apply(newAttrs, element);  // accumulates correctly
    }
    return attrs;   // BUG: discards all changes, should be newAttrs
};

Expected Behavior

AnnotationEnhancer beans registered in the Spring context should be able to override @RocketMQMessageListener annotation attributes (e.g. topic, consumerGroup) at runtime.

Actual Behavior

All AnnotationEnhancer customizations are silently ignored. The original annotation attributes are always used.

Impact

Any application that relies on AnnotationEnhancer to dynamically override @RocketMQMessageListener attributes — for example, injecting topic or consumerGroup from environment properties — will find their customizations have no effect.

Fix

Return newAttrs instead of attrs:

return newAttrs;

A pull request with the fix has been submitted: #775