tests/testlib/crash_transaction_late.py

engine: make hook point for extension a public function

Well there are no private public functions in Python, but we generally treat
functions and variables starting with `_` as private ones.

A function which needs to be overrided in extension should be a public one.

Differential Revision: https://phab.mercurial-scm.org/D9672

# tiny extension to abort a transaction very late during test
#
# Copyright 2020 Pierre-Yves David <[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

from mercurial import (
    error,
    transaction,
)


def abort(fp):
    raise error.Abort(b"This is a late abort")


def reposetup(ui, repo):

    transaction.postfinalizegenerators.add(b'late-abort')

    class LateAbortRepo(repo.__class__):
        def transaction(self, *args, **kwargs):
            tr = super(LateAbortRepo, self).transaction(*args, **kwargs)
            tr.addfilegenerator(
                b'late-abort', [b'late-abort'], abort, order=9999999
            )
            return tr

    repo.__class__ = LateAbortRepo