//ecPopupCtrl.pas:
//add property TCustomAutoCompletePopup/TAutoCompletePopup.ShowWhenNone: boolean

function TCustomAutoCompletePopup.FilterItems: Boolean;
var ..
  b: boolean;
begin
  ...
  b := false;
  for i := 0 to FItems.Count - 1 do
    if FilterItem(i, filt) then
    begin
      FComplRender.AddIndex(i);
      b := true;
    end;
  if not FShowWhenNone and not b then
    begin Result:= False; Exit end;
  ...
