rails/rails — pull request #6671 by mrbrdo (2012-06-07 22:36:39+00:00)
Title: Bad Regexp exploits "fix" master branch

See https://github.com/rails/rails/pull/6569
This is a backport for 3-2-stable branch with exception changed to a deprecation warning.

I only ran ActiveModel tests, so if you have bad test isolation you might have to fix some tests outside ActiveModel, if they use validates_format_of :)