def set_cookie(src, dst)
      if str = src['set-cookie']
        cookies = []
        str.split(/,\s*/).each{|token|
          if /^[^=]+;/o =~ token
            cookies[-1] << ", " << token
          elsif /=/o =~ token
            cookies << token
          else
            cookies[-1] << ", " << token
          end
        }
        dst.cookies.replace(cookies)
      end
    end
def set_cookie(src, dst)
      if str = src['set-cookie']
        cookies = []
        str.split(/,\s*/).each{|token|
          if /^[^=]+;/o =~ token
            cookies[-1] << ", " << token
          elsif /=/o =~ token
            cookies << token
          else
            cookies[-1] << ", " << token
          end
        }
        dst.cookies.replace(cookies)
      end
    end
Net::HTTP is stupid about the multiple header fields.
 Here is workaround: