rails/rails — pull request #11194 by yangchenyun (2013-06-30 09:28:33+00:00)
Title: rename ActiveSupport::Callbacks::Callback#merge to inverse_cond_merge

the `merge` in the context doesn't following the normal `merge` logic for an hash object.
The name is counter-intuitive to understand the behavior.
It in fact inverses the conditions before merge all the options, name if `inverse_conf_merge` to provide a good summary about how it works.