add prechangegroup and pretxnchangegroup hooks.
prechangegroup lets you stop push, pull or unbundle before it begins.
pretxnchangegroup lets you inspect changegroup before transaction is
committed, and roll back if you not like it.
#!/usr/bin/env python
#
# An example CGI script to export multiple hgweb repos, edit as necessary
import cgitb, sys
cgitb.enable()
# sys.path.insert(0, "/path/to/python/lib") # if not a system-wide install
from mercurial import hgweb
# The config file looks like this:
# [paths]
# virtual/path = /real/path
# virtual/path = /real/path
# Alternatively you can pass a list of ('virtual/path', '/real/path') tuples
# or use a dictionary with entries like 'virtual/path': '/real/path'
h = hgweb.hgwebdir("hgweb.config")
h.run()