SpringBoot defaultRequestConfigCustomizer on HttpComponentsClientHttpRequestFactoryBuilder seems inconsistent

Hello,

I have an inquiry regarding https://github.com/spring-projects/spring-boot/blob/main/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/http/client/HttpComponentsClientHttpRequestFactoryBuilder.java#L181

The method is defined as

        /**
     * Return a new {@link HttpComponentsClientHttpRequestFactoryBuilder} that applies
     * additional customization to the underlying
     * {@link org.apache.hc.client5.http.config.RequestConfig.Builder} used for default
     * requests.
     * @param defaultRequestConfigCustomizer the customizer to apply
     * @return a new {@link HttpComponentsClientHttpRequestFactoryBuilder} instance
     */
    public HttpComponentsClientHttpRequestFactoryBuilder withDefaultRequestConfigCustomizer(
            Consumer<RequestConfig.Builder> defaultRequestConfigCustomizer) {
        Assert.notNull(defaultRequestConfigCustomizer, "'defaultRequestConfigCustomizer' must not be null");
        return new HttpComponentsClientHttpRequestFactoryBuilder(getCustomizers(), this.httpClientCustomizer,
                this.connectionManagerCustomizer, this.socketConfigCustomizer, defaultRequestConfigCustomizer,
                this.tlsSocketStrategyFactory);
    }

according to the javadoc, the input request config builder customizer should apply addition customization, but the implementation actually replaces the previous behavior.

Is there a reason to not have this.defaultRequestConfigCustomizer.andThen(defaultRequestConfigCustomizer) instead?

Comment From: nosan

This method was added at the last moment https://github.com/spring-projects/spring-boot/issues/43139, and I think missing andThen is just an oversight.

Comment From: philwebb

Closing in favor of PR #43429. Thanks @nosan!