rails/rails — pull request #3785 by lest (2011-11-28 16:35:31+00:00)
Title: Put backtrace_cleaner to env

Get `backtrace_cleaner` from env instead of `defined?(Rails) && Rails.respond_to?(:backtrace_cleaner) ...`

Also there is an option to set `action_dispatch.backtrace_cleaner` only when exception is catched http://git.io/qIpAYw#L28 but I'm unsure about it.

/cc @josevalim