mercurial/node.py

revlog: don't say "not found" on internal error

If index_node() returned NULL, then index_find_node() and and
nt_partialmatch() used to return -2 to signal that the node was not
found. However, we were passing in a revnum to index_node() that we
knew should exist, so the only reason it could return NULL was due to
some internal error or perhaps out of memory. Let's not use "not
found" for these cases. I suppose we never noticed this because these
error never happen in practice.

I think there are more places where we should error out instead of
reporting that the node was not found, but the cases mentioned above
were all I cared about right now (because using the same error code
for all failures simplified some future patches).

Differential Revision: https://phab.mercurial-scm.org/D3457

# 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
# Adapt to Python 3 API changes. If this ends up showing up in
# profiles, we can use this version only on Python 3, and forward
# binascii.unhexlify like we used to on Python 2.
def bin(s):
    try:
        return binascii.unhexlify(s)
    except binascii.Error as e:
        raise TypeError(e)

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'

wdirfilenodeids = {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])