Ещё правки VCL (16)

procedure TApplication.ControlDestroyed(Control: TControl);
begin
  if FMainForm = Control then FMainForm := nil;
  if FMouseControl = Control then FMouseControl := nil;
  if Screen.FActiveControl = Control then Screen.FActiveControl := nil;
  if Screen.FActiveCustomForm = Control then
  begin
   If (Control Is TCustomForm) and (TCustomForm(Control).FormStyle = fsMDIChild) then {V}
   begin
     Screen.FActiveCustomForm := FMainForm;
     Screen.FActiveForm := FMainForm;
   end
   else
   begin
     Screen.FActiveCustomForm := nil;
     Screen.FActiveForm := nil;
   end
  end;
  if Screen.FFocusedForm = Control then Screen.FFocusedForm := nil;
  if FHintControl = Control then FHintControl := nil;
  Screen.UpdateLastActive;
end;