rails/rails — pull request #10260 by ikstrm (2013-04-18 10:23:51+00:00)
Title: Unify the format of returning nil

In the rails source code, there are two cases when returning nil with "if" in one line.

* return nil if ...
* return if ...

They are the same meaning.
So I thought they should be unified.
I did grep, and I found that the latter case is major in the rails source code.
I replaced all of the former cases.