rails/rails — pull request #12216 by suginoy (2013-09-13 09:42:41+00:00)
Title: Fix typos: the indefinite articles(a -> an).

I've git-grepped 'a a', 'a i', 'a u', 'a e', 'a o' and fixed all typos. ref #12126
Sorry for my insignificant PR.