anchor.diff:              {stop, changes_timeout}
           end;
       {ibrowse_async_headers, ReqId, "404", _} ->
  -        catch ibrowse:stop_worker_process(Pid),
  +        stop_link_worker(Pid),
           ?LOG_INFO("source doesn't have _changes, trying _all_docs_by_seq", []),
           Self = self(),
           BySeqPid = spawn_link(fun() -> by_seq_loop(Self, Source, Since) end),
  
positive.code:     ibrowse:stream_next(S#state.reqid);
  maybe_stream_next(_) ->
      timer:cancel(get(timeout)).
  
negative.code:     {noreply, State};
  handle_headers(Code, Hdrs, #state{init_args = InitArgs} = State)
          when Code =:= 301 ; Code =:= 302 ->
      stop_link_worker(State#state.conn),
      [Parent, #http_db{url = Url1} = Source, Since, PostProps] = InitArgs,
      Url = couch_rep_httpc:redirect_url(Hdrs, Url1),
      Source2 = couch_rep_httpc:redirected_request(Source, Url),
  