view tests/testlib/crash_transaction_late.py @ 50391:12f13b13f414 stable

revlog: avoid possible collision between directory and temporary index

Since 6.4, we create a temporary index file to write the split data without
overwriting the inline version too early. However, the store encoding does not
prevent these new `.i.s` file to collide with a directory with the same name.
While the odds for such a collision to happens are fairly low, the collision
would prevent Mercurial from working.

The store encoding have a mitigation solution in place to prevent such
collisions from happening for `.i` and `.d` files, but not for other extensions.
We cannot update this encoding scheme to solve the issue since it would diverge
from older version of Mercurial.

Instead, we create an alternative directory tree dedicated to such files.
The use of the `.i` extension combined with store encoding will prevent
collisions there.

# 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 mercurial import (
    error,
)


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


def reposetup(ui, repo):
    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,
                post_finalize=True,
            )
            return tr

    repo.__class__ = LateAbortRepo