mercurial/node.py

rebase: initial support for multiple destinations

This patch defines `SRC` (a single source revision) and `ALLSRC` (all source
revisions) to be valid names in  `--dest` revset if `--src` or `--rev` is
used. So destination could be defined differently according to source
revisions. The names are capitalized to make it clear they are "dynamically
defined", distinguishable from normal revsets (Thanks Augie for the
suggestion).

This is useful, for example, `-r 'orphan()' -d 'calc-dest(SRC)'` to solve
instability, which seems to be a highly wanted feature.

The feature is not completed, namely if `-d` overlaps with `-r`, things
could go wrong. A later patch will handle that case.

The feature is also gated by `experimental.rebase.multidest` config option
which is default off.

Differential Revision: https://phab.mercurial-scm.org/D469

# 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 = {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
wdirhex = hex(wdirid)

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