delete_cookie_header! (lib/rack/utils.rb)

# File lib/rack/utils.rb, line 327
    def delete_cookie_header!(header, key, value = {})
      case header["Set-Cookie"]
      when nil, ''
        cookies = []
      when String
        cookies = header["Set-Cookie"].split("\n")
      when Array
        cookies = header["Set-Cookie"]
      end

      cookies.reject! { |cookie|
        if value[:domain]
          cookie =~ /\A#{escape(key)}=.*domain=#{value[:domain]}/
        elsif value[:path]
          cookie =~ /\A#{escape(key)}=.*path=#{value[:path]}/
        else
          cookie =~ /\A#{escape(key)}=/
        end
      }

      header["Set-Cookie"] = cookies.join("\n")

      set_cookie_header!(header, key,
                 {:value => '', :path => nil, :domain => nil,
                   :max_age => '0',
                   :expires => Time.at(0) }.merge(value))

      nil
    end