changegroup: populate _clnodetorev as part of changelog linknode lookup The thing that matters is that self._clnodetorev is populated with changesets that are being sent. Back when this code was in an extension, it wasn't possible to monkeypatch the changelog lookup function. Now that the code is in core, we can move this code to where it logically belongs. Differential Revision: https://phab.mercurial-scm.org/D4186