Rails::Application#config_for merges shared configuration deeply

[kirikiriyamama]

Summary

I'm using some gems to manage environment specific configurations, but I'd like to migrate to the Rails features. However, my configurations are nested deeply, and Rails::Application#config_for doesn't merge deeply.

# config/application.yml
shared:
  foo:
    bar:
      baz: 1
development:
  foo:
    bar:
      qux: 2

# currently
config_for(:application)[:foo][:bar] #=> { qux: 2 }
# I expect
config_for(:application)[:foo][:bar] #=> { baz: 1, qux: 2 }

I know it's a breaking change. If changing the default behavior is difficult, for instance, how about controlling it by an option?

[rafaelfranca]

Can you add a CHANGELOG entry?

[kirikiriyamama]

@rafaelfranca I've added it by 2b17c11