mercurial/node.py

strip: enhance repair.strip to receive a list of nodes (issue3299)

Originally, mq.strip called repair.strip a single rev at a time.
repair.strip stores in a backup bundle any revision greater than
the revision being stripped, strips, then restores the backup with
repo.addchangegroup. So, when stripping revisions on more than one
topological branch, some could end up being restored from the backup
bundle, only to be later removed by a subsequent repair.strip call.

But repo.addchangegroup calls hooks for all those restore operations.
And 9df9444e96ec changed it to delay all hook calls until the
repository lock were released - by mq.strip, after stripping all
revisions. Thus, the hooks could be called over revisions already
removed from the repository at that point.

By generating the revision lists at once inside repo.strip, we avoid
calling addchangegroup for temporary restores. Incidentally, this
also avoids creating many backup files for a single strip command.

# 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])