view mercurial/node.py @ 24995:0579b0c2ea2b

tryimportone: use dirstateguard instead of beginparentchange/endparentchange

To fix the issue that the recent (in memory) dirstate isn't visible to
external process (e.g. "precommit" hook), a subsequent patch makes
"localrepository.commit()" invoke "dirstate.write()" in it.

This change will make "beginparentchange()" and "endparentchange()" on
dirstate in "cmdutil.tryimportone()" meaningless, because:

  - "dirstate.write()" writes changed data into ".hg/dirstate", but

  - aborting between "beginparentchange()" and "endparentchange()"
    doesn't cause any restoring ".hg/dirstate"

    it just discards changes in memory.

This patch uses "dirstateguard" instead of "beginparentchange()" and
"endparentchange()" in "cmdutil.tryimportone()" to restore
".hg/dirstate" during a failure even if "dirstate.write()" is executed
before a failure.

This patch uses "lockmod.release(dsguard)" instead of
"dsguard.release()", because processing may be aborted before
assignment to "dsguard" , and the "if dsguard" examination for safety is
redundant.

# 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])