class Rack::Multipart::Generator

def content_for_tempfile(io, file, name)
  length = ::File.stat(file.path).size if file.path
  filename = "; filename=\"#{Utils.escape_path(file.original_filename)}\""

LTIPART_BOUNDARY}\r
t-disposition: form-data; name="#{name}"#{filename}\r
t-type: #{file.content_type}\r
tent-length: #{length}\r\n" if length}\r
ead}\r
end