fields_for with inline blocks and nested attributes already persisted does not render properly

When using nested attributes and editing a record, the fields_for block does not render properly.

This does not work:

<%= f.fields_for(:addresses) { |builder| render 'addresses/fields', :f => builder  } %>

This works:

<%= f.fields_for(:addresses) do |builder|  %>
  <%= render 'addresses/fields', :f => builder %>
<% end %>

There is a detailed explanation of this issue in SimpleForm issue tracker:
https://github.com/plataformatec/simple_form/issues/closed#issue/181

There is also an example app showing the issue in my github:
https://github.com/carlosantoniodasilva/simple_form_foobar

Tested on both master and 3.0.3 stable version.