Add 'rails/' from commit '3d1ae2b67324ead807286f7e0c60ad293fdd5e07'

git-subtree-dir: rails
git-subtree-mainline: 3d1ae2b67324ead807286f7e0c60ad293fdd5e07
git-subtree-split: 3d1ae2b67324ead807286f7e0c60ad293fdd5e07
code restyle and exception added