tests/mockblackbox.py

nodemap: add a test about racy commit during stream clone

That test show that the resulting client nodemap is different from the server
one. This happens because the server one transferred a corrupted node map. The
data file match the pre-commit content while the docket has post commit content.
As the result the nodemap was detected invalid and recomputed.

When running without the rust implementation, the code is also generating a new
datafile unconditionally, This mean the older file is no longer there are
transfer time, resulting in a crash.

We will fix this issue later, but we start with writing tests highlighting the
issue.

Differential Revision: https://phab.mercurial-scm.org/D10479

from __future__ import absolute_import
from mercurial.utils import procutil

# XXX: we should probably offer a devel option to do this in blackbox directly
def getuser():
    return b'bob'


def getpid():
    return 5000


# mock the date and user apis so the output is always the same
def uisetup(ui):
    procutil.getuser = getuser
    procutil.getpid = getpid