mercurial/obsutil.py

rebase: clean up rebasestate from active transaction

Previously, rebase assumes the following pattern:

    rebase:
        with transaction as tr: # top-level
            ...
        tr.__close__ writes rebasestate
        unlink('rebasestate')

However it's possible that "rebase" was called inside a transaction:

    with transaction as tr1:
        rebase:
            with transaction as tr2: # not top-level
                ...
            tr2.__close__ does not write rebasestate
            unlink('rebasestate')
    tr1.__close__ writes rebasestate

That leaves a rebasestate on disk incorrectly.

This patch adds "removefilegenerator" to notify transaction code that the
state file is no longer needed therefore fixes the issue.

# obsutil.py - utility functions for obsolescence
#
# Copyright 2017 Boris Feld <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

from __future__ import absolute_import

def closestpredecessors(repo, nodeid):
    """yield the list of next predecessors pointing on visible changectx nodes

    This function respect the repoview filtering, filtered revision will be
    considered missing.
    """

    precursors = repo.obsstore.precursors
    stack = [nodeid]
    seen = set(stack)

    while stack:
        current = stack.pop()
        currentpreccs = precursors.get(current, ())

        for prec in currentpreccs:
            precnodeid = prec[0]

            # Basic cycle protection
            if precnodeid in seen:
                continue
            seen.add(precnodeid)

            if precnodeid in repo:
                yield precnodeid
            else:
                stack.append(precnodeid)