view mercurial/txnutil.py @ 41120:79f8f032c706

amend: add config option to update time to current in hg amend (issue5828)

The given config option i.e. `rewrite.update-timestamp` updates date to
current when //True//. However when only date is to be updated to current
with the working directory clean and no other attributes changing then it
does not amend as stated in issue 5828. Further when `--date` flag is specified
along with the new config option then `--date` is given priority over the
config option.

Differential Revision: https://phab.mercurial-scm.org/D5491

# txnutil.py - transaction related utilities
#
#  Copyright FUJIWARA Katsunori <[e-mail]> 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)