anchor.diff:  end;
   
   procedure TmCustomVirtualDataset.InternalOpen;
  +var
  +  i : integer;
   begin
     FInternalOpen := True;
     InternalFirst;
  
positive.code: end;
  
  function TmCustomVirtualDataset.CompareBookmarks(Bookmark1, Bookmark2: TBookmark): Longint;
  //const
  //  RetCodes: array [Boolean, Boolean] of ShortInt = ((2, -1), (1, 0));
  var
    tmpLongint1, tmpLongint2 : longint;
  begin
    if (Bookmark1 = nil) then
    begin
  
negative.code: end;
  
  function TmCustomVirtualDataset.BookmarkValid(ABookmark: TBookmark): Boolean;
  begin
    if Assigned(ABookmark) and (PLongint(ABookmark)^ >= 0) and
      (PLongint(ABookmark)^ < RecordCount) then
      Result := True
    else
      Result := False;
  end;
  
  procedure TmCustomVirtualDataset.BufferToVariant(AField: TField;
  