ssh: add capability detection at startup Because older servers don't return any output for unknown commands, it's tricky to add new commands. The approach is this: we add a "hello" command that reports any interesting capabilities (and other things that might be of interest in the future). To detect whether this new command is supported, we issue both it and our startup detection command ("between") at the beginning of a connection.

"""
node.py - basic nodeid manipulation for mercurial

Copyright 2005 Matt Mackall <mpm@selenic.com>

This software may be used and distributed according to the terms
of the GNU General Public License, incorporated herein by reference.
"""

import binascii

nullid = "\0" * 20

def hex(node):
    return binascii.hexlify(node)

def bin(node):
    return binascii.unhexlify(node)

def short(node):
    return hex(node[:6])