rails/sprockets-rails — pull request #7 by jmbejar (2012-05-09 19:11:14+00:00)
Title: Make sure that javascript_include_tag/stylesheet_link_tag methods discard repeated assets

Ensure that these helper methods include only once every asset.

Actually, this is the behavior when you create a rails app without sprockets_rails (with the flag --skip-sprocket)

Discussion related here: https://github.com/rails/rails/pull/6149