view mercurial/node.py @ 17003:42c472877825

revset: add a utility for obtaining the source of a given rev

graft, transplant and rebase all embed a different type of source marker in
extra, and each with a different name.  The current implementation of each is
such that there will never be more than one of these markers on a node.

Note that the rebase marker can only be resolved if the source is
still present, which excludes the typical rebase usage (without
--keep) from consideration (unless the resulting bundle in
strip-backup is overlayed). There probably isn't any reason to use
rebase --keep as a substitute for transplant or graft at this point,
but maybe there was at one point and there are even a few rebases in
the hg repo, so it may be of historical interest.

# 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])