view mercurial/node.py @ 30867:aaa751585325

pager: don't terminate with extreme prejudice on SIGPIPE (BC)

The default SIGPIPE handler causes Mercurial to exit immediately, without
running any Python cleanup code (except and finally blocks, atexit handlers
etc). This creates problems if you want to do something at exit.

If we need a different exit code for broken pipe from pager, then we should
code that ourselves in Python; this appears to have been cargo-culted from
the fork implementation of pager that's no longer used, where it was needed
to stop Broken Pipe errors appearing on the user's terminal.

# 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.

from __future__ import absolute_import

import binascii

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

nullrev = -1
nullid = b"\0" * 20
nullhex = hex(nullid)

# Phony node value to stand-in for new files in some uses of
# manifests.
newnodeid = '!' * 20
addednodeid = ('0' * 15) + 'added'
modifiednodeid = ('0' * 12) + 'modified'

wdirnodes = set((newnodeid, addednodeid, modifiednodeid))

# pseudo identifiers for working directory
# (they are experimental, so don't add too many dependencies on them)
wdirrev = 0x7fffffff
wdirid = b"\xff" * 20

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