title: Flash message not working on Rails 4 after a redirect
body: <pre><code>  def show
      email_address = EmailAddress.find_by(confirmation_token: params[:id])
      if email_address.confirm!
        flash[:notice] = "Thanks for confirming your email address (#{email_address.email})"
        flash.keep
        redirect_to user_account_path
      else
        flash[:error] = "Invalid confirmation token"
        redirect_to root_path
      end
    end
  </code></pre>
  
  <p>Trying to redirect from this controller to another controller and i want to flash <code>"Thanks for confirming your email address (#{email_address.email})"</code> but am not seeing the flash message on the page am redirecting to.</p>
  
  <p>Tried hardcoding a flash message on the other controller and it got displayed.
  It's only when I do a redirect the flash message doesn't go through.</p>