view mercurial/txnutil.py @ 41281:183df3df6031

resolve: fix mark-check when a file was deleted on one side (issue6020) wvfs.open raises an error if one of the files does not exist. Ignoring the error if it's ENOENT is done in several other places in this code, so I'm in good company :) Differential Revision: https://phab.mercurial-scm.org/D5243
author Kyle Lippincott <spectral@google.com>
date Wed, 07 Nov 2018 15:45:09 -0800
parents 206532700213
children 2372284d9457
line wrap: on
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# txnutil.py - transaction related utilities
#
#  Copyright FUJIWARA Katsunori <foozy@lares.dti.ne.jp> and others
#
# 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 errno

from . import (
    encoding,
)

def mayhavepending(root):
    '''return whether 'root' may have pending changes, which are
    visible to this process.
    '''
    return root == encoding.environ.get('HG_PENDING')

def trypending(root, vfs, filename, **kwargs):
    '''Open  file to be read according to HG_PENDING environment variable

    This opens '.pending' of specified 'filename' only when HG_PENDING
    is equal to 'root'.

    This returns '(fp, is_pending_opened)' tuple.
    '''
    if mayhavepending(root):
        try:
            return (vfs('%s.pending' % filename, **kwargs), True)
        except IOError as inst:
            if inst.errno != errno.ENOENT:
                raise
    return (vfs(filename, **kwargs), False)