Upgrade to 2.1.0.RC1 breaks message source with DevTools

[vpavic]

A Spring Boot app that has a message source in default location (i.e. messages.properties in src/main/resources) suddenly stopped resolving messages after upgrade to 2.1.0.RC1 when started from IDE.

I've tracked this to enabling of spring.messages.reloadable for DevTools that was done in #14699 - I believe this shouldn't have been done with the existing default for spring.messages.basename (i.e. messages), since ReloadableResourceBundleMessageSource won't resolve the supplied basename from the classpath unless explicitly prefixed with classpath:.

Having said that I've tried setting spring.messages.basename to classpath:messages but that didn't work either.

[snicoll]

Thanks a lot Vedran, that's an oversight on my end as this issue was already raised in Spring Petclinic and I forgot to report it here.

[wilkinsona]

Thanks, @vpavic.

Having said that I've tried setting spring.messages.basename to classpath:messages but that didn't work either.

This doesn't work because of the custom ResourceBundleCondition that causes the auto-configuration to back off as it ends up looking for classpath*:classpath:messages.properties which doesn't exist.

[wilkinsona]

There are a few problems here:

1. Setting spring.messages.reloadable: true makes the default basename of messages useless
2. Setting the basename to classpath:messages should work with ReloadableResourceBundleMessageSource but the custom condition causes the auto-configuration to back off
3. DevTools enables the broken behaviour by default

[wilkinsona]

We've decided to revert #14699 and #13377. With the benefit of hindsight, the approach take in #13377 isn't quite right as it causes problems 1 and 2 described above. We'd like to give ourselves time to consider alternative approaches and, with 2.1.0.RELEASE due tomorrow, the enhancement will have to wait for a future release.