view mercurial/node.py @ 13447:931a72e00efa stable

introduce new RequirementError (issue2649)

This improves the misleading error message

  $ hg identify
  abort: there is no Mercurial repository here (.hg not found)!

to the more explicit

  $ hg identify
  abort: requirement 'fake' not supported!

for all commands in commands.optionalrepo, which includes the identify
and serve commands in particular.

This is for the case when a new entry in .hg/requires will be defined
in a future Mercurial release.

# node.py - basic nodeid manipulation for mercurial
#
# Copyright 2005, 2006 Matt Mackall <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

import binascii

nullrev = -1
nullid = "\0" * 20

# This ugly style has a noticeable effect in manifest parsing
hex = binascii.hexlify
bin = binascii.unhexlify

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