rails--rails/activesupport/CHANGELOG.md

*  Add `action_controller_api` and `action_controller_base` load hooks to be called in `ActiveSupport.on_load`

    `ActionController::Base` and `ActionController::API` have differing implementations. This means that
    the one umbrella hook `action_controller` is not able to address certain situations where a method
    may not exist in a certain implementation.

    This is fixed by adding two new hooks so you can target `ActionController::Base` vs `ActionController::API`

    Fixes #27013.

    *Julian Nadeau*

*   Add `fetch_values` for `HashWithIndifferentAccess`

    The method was originally added to `Hash` in Ruby 2.3.0.

    *Josh Pencheon*

Please check [5-1-stable](https://github.com/rails/rails/blob/5-1-stable/activesupport/CHANGELOG.md) for previous changes.