amatsuda/kaminari — pull request #322 by harai (2012-12-14 01:51:02+00:00)
Title: Supported route prefix (or namespace) which was added in Rails 3.1.

Supported mountable engine's route prefix (or namespace), which was added in Rails 3.1.

Refinery CMS 2, the most popular cms which supports Rails 3.2, requires this feature because it has highly modularized design and it is common to refer to other engine's url from view.