view mercurial/scmwindows.py @ 30001:e38d85be978f

repair: open a file with checkambig=True to avoid file stat ambiguity

Before this patch, if steps below occurs at "the same time in sec",
all of mtime, ctime and size are same between (1) and (3).

  1. append data to revlog-style file (and close transaction)
  2. discard appended data by truncation of strip
  3. append same size but different data to revlog-style file again

Therefore, cache validation doesn't work after (3) as expected.

To avoid such file stat ambiguity around truncation, this patch opens
a file with checkambig=True.

This patch also introduces "with" statement style, to ensure immediate
invocation of close() after truncation, because closing file is the
only trigger to check (and get rid of) file stat ambiguity.

This is a part of ExactCacheValidationPlan.

    https://www.mercurial-scm.org/wiki/ExactCacheValidationPlan

from __future__ import absolute_import

import os

from . import (
    osutil,
    util,
)

try:
    import _winreg as winreg
    winreg.CloseKey
except ImportError:
    import winreg

def systemrcpath():
    '''return default os-specific hgrc search path'''
    rcpath = []
    filename = util.executablepath()
    # Use mercurial.ini found in directory with hg.exe
    progrc = os.path.join(os.path.dirname(filename), 'mercurial.ini')
    rcpath.append(progrc)
    # Use hgrc.d found in directory with hg.exe
    progrcd = os.path.join(os.path.dirname(filename), 'hgrc.d')
    if os.path.isdir(progrcd):
        for f, kind in osutil.listdir(progrcd):
            if f.endswith('.rc'):
                rcpath.append(os.path.join(progrcd, f))
    # else look for a system rcpath in the registry
    value = util.lookupreg('SOFTWARE\\Mercurial', None,
                           winreg.HKEY_LOCAL_MACHINE)
    if not isinstance(value, str) or not value:
        return rcpath
    value = util.localpath(value)
    for p in value.split(os.pathsep):
        if p.lower().endswith('mercurial.ini'):
            rcpath.append(p)
        elif os.path.isdir(p):
            for f, kind in osutil.listdir(p):
                if f.endswith('.rc'):
                    rcpath.append(os.path.join(p, f))
    return rcpath

def userrcpath():
    '''return os-specific hgrc search path to the user dir'''
    home = os.path.expanduser('~')
    path = [os.path.join(home, 'mercurial.ini'),
            os.path.join(home, '.hgrc')]
    userprofile = os.environ.get('USERPROFILE')
    if userprofile and userprofile != home:
        path.append(os.path.join(userprofile, 'mercurial.ini'))
        path.append(os.path.join(userprofile, '.hgrc'))
    return path