merb

Patch that provides an error message with a more detailed explanation of why a call to content_type failed.

The need for this message arose when using merbful_authentication in the following way:

class Blogs < Application
  provides :html
  before :login_required

  def index
    provides :rss
    ...
  end
end

Here, login_required is called before provides(:rss) is called. When login_required checks for the content_type on the /blogs.rss request, it appears as if the rss format is not provided.