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

#!/usr/bin/env python3
#
# An example hgweb CGI script, edit as necessary
# See also https://mercurial-scm.org/wiki/PublishingRepositories

# Path to repo or hgweb config to serve (see 'hg help hgweb')
config = b"/path/to/repo/or/config"

# Uncomment and adjust if Mercurial is not installed system-wide
# (consult "installed modules" path from 'hg debuginstall'):
# import sys; sys.path.insert(0, "/path/to/python/lib")

# Uncomment to send python tracebacks to the browser if an error occurs:
# import cgitb; cgitb.enable()

from mercurial import demandimport

demandimport.enable()
from mercurial.hgweb import hgweb, wsgicgi

application = hgweb(config)
wsgicgi.launch(application)