Spring Data R2DBC sample broke with upgrade to Spring Boot 2.5.1

[elefeint]

In SpringDataR2dbcApp, the Spring Data sample programmatically instantiates a ConnectionFactory object. This used to work, with Spring Boot creating DatabaseClient and repository objects based on the application-provided ConnectionFactory.

However, after upgrade to Spring Boot 2.5.1, the sample failed to start at autoconfiguration with Caused by: java.lang.IllegalArgumentException: Cannot determine database's type as ConnectionFactory is not options-capable. This issue goes away in Spring Boot 2.5.2; however, I'd expect it to keep breaking, as creating a ConnectionFactory manually is no longer the recommended Spring Boot approach.

We have two options:

1. Configure the data source with a property instead of programmatically. I prefer this, since that's how the majority of our users will be using R2DBC with Spring Boot.
2. Use Spring Boot's ConnectionFactoryBuilder, as described in this comment