hgweb.cgi

cmdserver: forcibly use L channel to read password input (issue3161)

Command server is designed to use the channel protocol even if the server
process is accessible to tty, whereas vanilla hg should be able to read
password from tty in that case.  So it isn't enough to swap sys.stdin:

    # works only if the server process is detached from the console
    sys.stdin = self.fin
    getpass.getpass('')
    sys.stdin = oldin

or test isatty:

    # vanilla hg can't talk to tty if stdin is redirected
    if self._isatty(self.fin):
        return getpass.getpass('')
    else:
        ...

Since ui.nontty flag is undocumented and command-server channels don't provide
isatty(), this change won't affect the other uses of ui._isatty().

issue3161 also suggests to provide some context of messages.  I think it can
be implemented by using the generic templating function.

#!/usr/bin/env python
#
# An example hgweb CGI script, edit as necessary
# See also http://mercurial.selenic.com/wiki/PublishingRepositories

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