revlog: backout e5750c6716eb This regresses performance of 'hg branches', presumably because it's visiting the revlog in the wrong order. This suggests we either need to fix the branch code or add some read-behind to mitigate the effect.

wireprotocol: use visibleheads as reference while unbundling (issue 3303) The `repo` object here is *always* local. Using `repo.heads()` ensure we will reject push if any secret changeset exists. During discovery, `visibleheads` were sent to the peer. So we can only expect it to send us `visibleheads` back. If any secret changeset exists:: visibleheads != repo.heads() This fix server side part of issue 3303 when pushing over the wire.