mercurial/node.py

rebase: fix rebase aborts when 'tip-1' is public (issue4082)

When aborting a rebase where tip-1 is public, rebase would fail to undo the merge
state. This caused unexpected dirstate parents and also caused unshelve to
become unabortable (since it uses rebase under the hood).

The problem was that rebase uses -2 as a marker rev, and when it checked for
immutableness during the abort, -2 got resolved to the second to last entry in
the phase cache.

Adds a test for the fix. Add exception to phase code to prevent this in the
future.

# 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])