Why can I access helper methods for one controller in the views for a different controller? Is there a way to disable this without hacking/patching Rails?
@George Schreiber's method doesn't work as of Rails 3.1; the code has changed significantly.
However, there's now an even better way to disable this feature in Rails 3.1 (and hopefully later). In your config/application.rb, add this line:
config.action_controller.include_all_helpers = false
This will prevent ApplicationController from loading all of the helpers.
(For anyone who is interested, here's the pull request where the feature was created.)