Added an probably unnecessay header: Content-Range when HTTP 416 is r…

…eturned

aiohttp/web_fileresponse.py

@@ -204,6 +204,17 @@ async def prepare(self, request):
  start = rng.start
  end = rng.stop
  except ValueError:
+ # https://tools.ietf.org/html/rfc7233:
+ # A server generating a 416 (Range Not Satisfiable) response to
+ # a byte-range request SHOULD send a Content-Range header field
+ # with an unsatisfied-range value. 
+ # The complete-length in a 416 response indicates the current
+ # length of the selected representation.
+ #
+ # Will do the same below. Many servers ignore this and do not
+ # send a Content-Range header with HTTP 416
+ self.headers[hdrs.CONTENT_RANGE] = 'bytes */{0}'.format(
+ file_size)
  self.set_status(HTTPRequestRangeNotSatisfiable.status_code)
  return await super().prepare(request)
 
@@ -238,6 +249,8 @@ async def prepare(self, request):
  # suffix-byte-range-spec with a non-zero suffix-length,
  # then the byte-range-set is satisfiable. Otherwise, the
  # byte-range-set is unsatisfiable.
+ self.headers[hdrs.CONTENT_RANGE] = 'bytes */{0}'.format(
+ file_size)
  self.set_status(HTTPRequestRangeNotSatisfiable.status_code)
  return await super().prepare(request)