mORMot Open Source

//-- This works fine
ContentLength := FileSize(FileName);
  if ContentLength=0 then
  begin
    result := true;
    exit;
  end;
  result := ContentLength <> 0;
  if result and
     (rfWantRange in ResponseFlags) then
    if not ValidateRange then
      result := false; // invalid offset
  if not result then
    // there is no such file available, or range clearly wrong
    exit;
  include(ResponseFlags, rfAcceptRange);