revlog: clarify which revision is added to 'tested' when using cached delta The tested delta revisions are added to the 'tested' set. These are the same revisions we pass to builddelta(). However, in one case, we add builddelta(rev)[3] to the set intead of adding 'rev' itself. In that particular case, that element is the same as the function's input revision (because self._generaldelta is true), so the effect is the same. Still, let's just add the function's input revision to avoid confusing future readers.