rails/rails — pull request #15878 by sgrif (2014-06-23 15:53:29+00:00)
Title: Revert #15502, and add a deprecation warning instead.

This is public API, and `simple_form` depends on the `nil` return value.
We need to go through a deprecation cycle to return a null object. If
people want hash access, they can access the hash.

Closes #15877