comparison mercurial/revlog.py @ 48851:d739cd69bb6a

revlog: return 0 for the fast_rank of nullrev

By convention, the rank of the null revision is 0. This particular revision is
never "physically" stored in the changelog, so it is a special case.

For consistency, the value `None` is still being returned for revlogs which do
not store the fast_rank property for any revision.

Differential Revision: https://phab.mercurial-scm.org/D12208

48850:656196c1d442

        This method returns the rank retrieved from the revlog in constant
        time. It makes no attempt at computing unknown values for versions of
        the revlog which do not persist the rank.
        """
        rank = self.index[rev][ENTRY_RANK]
        if rank == RANK_UNKNOWN:
            return None
        return rank

    def chainbase(self, rev):
        base = self._chainbasecache.get(rev)
        if base is not None:

48851:d739cd69bb6a

        This method returns the rank retrieved from the revlog in constant
        time. It makes no attempt at computing unknown values for versions of
        the revlog which do not persist the rank.
        """
        rank = self.index[rev][ENTRY_RANK]
        if self._format_version != CHANGELOGV2 or rank == RANK_UNKNOWN:
            return None
        if rev == nullrev:
            return 0  # convention
        return rank

    def chainbase(self, rev):
        base = self._chainbasecache.get(rev)
        if base is not None: