rails/rails — pull request #8735 by jejacks0n (2013-01-04 03:54:10+00:00)
Title: Ensure assets aren't duplicated when using sprockets require.

Addresses the problem by calling flatten on asset array before calling uniq.

I've created a separate pull request on rails/sprockets-rails that addresses the issue for Rails 4.

https://github.com/rails/sprockets-rails/pull/33