comparison mercurial/ui.py @ 43077:687b865b95ad

formatting: byteify all mercurial/ and hgext/ string literals

Done with

    python3.7 contrib/byteify-strings.py -i $(hg files 'set:mercurial/**.py - mercurial/thirdparty/** + hgext/**.py - hgext/fsmonitor/pywatchman/** - mercurial/__init__.py')
    black -l 80 -t py33 -S $(hg files 'set:**.py - mercurial/thirdparty/** - "contrib/python-zstandard/**" - hgext/fsmonitor/pywatchman/**')

# skip-blame mass-reformatting only

Differential Revision: https://phab.mercurial-scm.org/D6972

43076:2372284d9457

)

urlreq = util.urlreq

# for use with str.translate(None, _keepalnum), to keep just alphanumerics
_keepalnum = ''.join(
    c for c in map(pycompat.bytechr, range(256)) if not c.isalnum()
)

# The config knobs that will be altered (if unset) by ui.tweakdefaults.
tweakrc = b"""

showfunc = 1
word-diff = 1
"""

samplehgrcs = {
    'user': b"""# example user config (see 'hg help config' for more info)
[ui]
# name and email, e.g.
# username = Jane Doe <[e-mail]>
username =

#
# histedit =
# rebase =
# uncommit =
""",
    'cloned': b"""# example repository config (see 'hg help config' for more info)
[paths]
default = %s

# path aliases to other clones of this repo in URLs or filesystem paths
# (see 'hg help config.paths' for more info)

[ui]
# name and email (local to this repository, optional), e.g.
# username = Jane Doe <[e-mail]>
""",
    'local': b"""# example repository config (see 'hg help config' for more info)
[paths]
# path aliases to other clones of this repo in URLs or filesystem paths
# (see 'hg help config.paths' for more info)
#
# default         = http://example.com/hg/example-repo

[ui]
# name and email (local to this repository, optional), e.g.
# username = Jane Doe <[e-mail]>
""",
    'global': b"""# example system-wide hg config (see 'hg help config' for more info)

[ui]
# uncomment to disable color in command output
# (see 'hg help color' for details)
# color = never

            self.environ = encoding.environ

            self.httppasswordmgrdb = httppasswordmgrdbproxy()
            self._blockedtimes = collections.defaultdict(int)

        allowed = self.configlist('experimental', 'exportableenviron')
        if '*' in allowed:
            self._exportableenviron = self.environ
        else:
            self._exportableenviron = {}
            for k in allowed:
                if k in self.environ:

    def load(cls):
        """Create a ui and load global and user configs"""
        u = cls()
        # we always trust global config files and environment variables
        for t, f in rcutil.rccomponents():
            if t == 'path':
                u.readconfig(f, trust=True)
            elif t == 'items':
                sections = set()
                for section, name, value, source in f:
                    # do not set u._ocfg
                    # XXX clean this up once immutable config object is a thing
                    u._tcfg.set(section, name, value, source)
                    u._ucfg.set(section, name, value, source)
                    sections.add(section)
                for section in sections:
                    u.fixconfig(section=section)
            else:
                raise error.ProgrammingError('unknown rctype: %s' % t)
        u._maybetweakdefaults()
        return u

    def _maybetweakdefaults(self):
        if not self.configbool('ui', 'tweakdefaults'):
            return
        if self._tweaked or self.plain('tweakdefaults'):
            return

        # Note: it is SUPER IMPORTANT that you set self._tweaked to
        # True *before* any calls to setconfig(), otherwise you'll get
        # infinite recursion between setconfig and this method.
        #
        # TODO: We should extract an inner method in setconfig() to
        # avoid this weirdness.
        self._tweaked = True
        tmpcfg = config.config()
        tmpcfg.parse('<tweakdefaults>', tweakrc)
        for section in tmpcfg:
            for name, value in tmpcfg.items(section):
                if not self.hasconfig(section, name):
                    self.setconfig(section, name, value, "<tweakdefaults>")

    def copy(self):
        return self.__class__(self)

    def resetstate(self):

        # this is open-coded below - search for timeblockedsection to find them
        starttime = util.timer()
        try:
            yield
        finally:
            self._blockedtimes[key + '_blocked'] += (
                util.timer() - starttime
            ) * 1000

    @contextlib.contextmanager
    def uninterruptible(self):

        Most operations on a repository are safe to interrupt, but a
        few are risky (for example repair.strip). This context manager
        lets you advise Mercurial that something risky is happening so
        that control-C etc can be blocked if desired.
        """
        enabled = self.configbool('experimental', 'nointerrupt')
        if enabled and self.configbool(
            'experimental', 'nointerrupt-interactiveonly'
        ):
            enabled = self.interactive()
        if self._uninterruptible or not enabled:
            # if nointerrupt support is turned off, the process isn't
            # interactive, or we're already in an uninterruptible
            # block, do nothing.
            yield
            return

        def warn():
            self.warn(_("shutting down cleanly\n"))
            self.warn(
                _("press ^C again to terminate immediately (dangerous)\n")
            )
            return True

        with procutil.uninterruptible(warn):
            try:

        st = util.fstat(fp)
        if util.isowner(st):
            return True

        tusers, tgroups = self._trustusers, self._trustgroups
        if '*' in tusers or '*' in tgroups:
            return True

        user = util.username(st.st_uid)
        group = util.groupname(st.st_gid)
        if user in tusers or group in tgroups or user == util.username():
            return True

        if self._reportuntrusted:
            self.warn(
                _('not trusting file %s from untrusted ' 'user %s, group %s\n')
                % (f, user, group)
            )
        return False

    def readconfig(

            cfg.read(filename, fp, sections=sections, remap=remap)
            fp.close()
        except error.ConfigError as inst:
            if trusted:
                raise
            self.warn(_("ignored: %s\n") % stringutil.forcebytestr(inst))

        if self.plain():
            for k in (
                'debug',
                'fallbackencoding',
                'quiet',
                'slash',
                'logtemplate',
                'message-output',
                'statuscopies',
                'style',
                'traceback',
                'verbose',
            ):
                if k in cfg['ui']:
                    del cfg['ui'][k]
            for k, v in cfg.items('defaults'):
                del cfg['defaults'][k]
            for k, v in cfg.items('commands'):
                del cfg['commands'][k]
        # Don't remove aliases from the configuration if in the exceptionlist
        if self.plain('alias'):
            for k, v in cfg.items('alias'):
                del cfg['alias'][k]
        if self.plain('revsetalias'):
            for k, v in cfg.items('revsetalias'):
                del cfg['revsetalias'][k]
        if self.plain('templatealias'):
            for k, v in cfg.items('templatealias'):
                del cfg['templatealias'][k]

        if trusted:
            self._tcfg.update(cfg)
            self._tcfg.update(self._ocfg)
        self._ucfg.update(cfg)
        self._ucfg.update(self._ocfg)

        if root is None:
            root = os.path.expanduser('~')
        self.fixconfig(root=root)

    def fixconfig(self, root=None, section=None):
        if section in (None, 'paths'):
            # expand vars and ~
            # translate paths relative to root (or home) into absolute paths
            root = root or encoding.getcwd()
            for c in self._tcfg, self._ucfg, self._ocfg:
                for n, p in c.items('paths'):
                    # Ignore sub-options.
                    if ':' in n:
                        continue
                    if not p:
                        continue
                    if '%%' in p:
                        s = self.configsource('paths', n) or 'none'
                        self.warn(
                            _("(deprecated '%%' in path %s=%s from %s)\n")
                            % (n, p, s)
                        )
                        p = p.replace('%%', '%')
                    p = util.expandpath(p)
                    if not util.hasscheme(p) and not os.path.isabs(p):
                        p = os.path.normpath(os.path.join(root, p))
                    c.set("paths", n, p)

        if section in (None, 'ui'):
            # update ui options
            self._fmsgout, self._fmsgerr = _selectmsgdests(self)
            self.debugflag = self.configbool('ui', 'debug')
            self.verbose = self.debugflag or self.configbool('ui', 'verbose')
            self.quiet = not self.debugflag and self.configbool('ui', 'quiet')
            if self.verbose and self.quiet:
                self.quiet = self.verbose = False
            self._reportuntrusted = self.debugflag or self.configbool(
                "ui", "report_untrusted"
            )
            self.tracebackflag = self.configbool('ui', 'traceback')
            self.logblockedtimes = self.configbool('ui', 'logblockedtimes')

        if section in (None, 'trusted'):
            # update trust information
            self._trustusers.update(self.configlist('trusted', 'users'))
            self._trustgroups.update(self.configlist('trusted', 'groups'))

        if section in (None, b'devel', b'ui') and self.debugflag:
            tracked = set()
            if self.configbool(b'devel', b'debug.extensions'):
                tracked.add(b'extension')

    def restoreconfig(self, data):
        self._ocfg.restore(data[0])
        self._tcfg.restore(data[1])
        self._ucfg.restore(data[2])

    def setconfig(self, section, name, value, source=''):
        for cfg in (self._ocfg, self._tcfg, self._ucfg):
            cfg.set(section, name, value, source)
        self.fixconfig(section=section)
        self._maybetweakdefaults()

            if callable(item.default):
                itemdefault = item.default()
            else:
                itemdefault = item.default
        else:
            msg = "accessing unregistered config item: '%s.%s'"
            msg %= (section, name)
            self.develwarn(msg, 2, 'warn-config-unknown')

        if default is _unset:
            if item is None:
                value = default
            elif item.default is configitems.dynamicdefault:
                value = None
                msg = "config item requires an explicit default value: '%s.%s'"
                msg %= (section, name)
                self.develwarn(msg, 2, 'warn-config-default')
            else:
                value = itemdefault
        elif (
            item is not None
            and item.default is not configitems.dynamicdefault
            and default != itemdefault
        ):
            msg = (
                "specifying a mismatched default value for a registered "
                "config item: '%s.%s' '%s'"
            )
            msg %= (section, name, pycompat.bytestr(default))
            self.develwarn(msg, 2, 'warn-config-default')

        for s, n in alternates:
            candidate = self._data(untrusted).get(s, n, None)
            if candidate is not None:
                value = candidate

        if self.debugflag and not untrusted and self._reportuntrusted:
            for s, n in alternates:
                uvalue = self._ucfg.get(s, n)
                if uvalue is not None and uvalue != value:
                    self.debug(
                        "ignoring untrusted configuration option "
                        "%s.%s = %s\n" % (s, n, uvalue)
                    )
        return value

    def configsuboptions(self, section, name, default=_unset, untrusted=False):
        """Get a config option and all sub-options.

        is a dict of defined sub-options where keys and values are strings.
        """
        main = self.config(section, name, default, untrusted=untrusted)
        data = self._data(untrusted)
        sub = {}
        prefix = '%s:' % name
        for k, v in data.items(section):
            if k.startswith(prefix):
                sub[k[len(prefix) :]] = v

        if self.debugflag and not untrusted and self._reportuntrusted:
            for k, v in sub.items():
                uvalue = self._ucfg.get(section, '%s:%s' % (name, k))
                if uvalue is not None and uvalue != v:
                    self.debug(
                        'ignoring untrusted configuration option '
                        '%s:%s.%s = %s\n' % (section, name, k, uvalue)
                    )

        return main, sub

    def configpath(self, section, name, default=_unset, untrusted=False):
        'get a path config item, expanded relative to repo root or config file'
        v = self.config(section, name, default, untrusted)
        if v is None:
            return None
        if not os.path.isabs(v) or "://" not in v:
            src = self.configsource(section, name, untrusted)
            if ':' in src:
                base = os.path.dirname(src.rsplit(':')[0])
                v = os.path.join(base, os.path.expanduser(v))
        return v

    def configbool(self, section, name, default=_unset, untrusted=False):
        """parse a configuration element as a boolean

        if isinstance(v, bool):
            return v
        b = stringutil.parsebool(v)
        if b is None:
            raise error.ConfigError(
                _("%s.%s is not a boolean ('%s')") % (section, name, v)
            )
        return b

    def configwith(
        self, convert, section, name, default=_unset, desc=None, untrusted=False

            return convert(v)
        except (ValueError, error.ParseError):
            if desc is None:
                desc = pycompat.sysbytes(convert.__name__)
            raise error.ConfigError(
                _("%s.%s is not a valid %s ('%s')") % (section, name, desc, v)
            )

    def configint(self, section, name, default=_unset, untrusted=False):
        """parse a configuration element as an integer

            ...
        ConfigError: foo.invalid is not a valid integer ('somevalue')
        """

        return self.configwith(
            int, section, name, default, 'integer', untrusted
        )

    def configbytes(self, section, name, default=_unset, untrusted=False):
        """parse a configuration element as a quantity in bytes

            return value
        try:
            return util.sizetoint(value)
        except error.ParseError:
            raise error.ConfigError(
                _("%s.%s is not a byte quantity ('%s')")
                % (section, name, value)
            )

    def configlist(self, section, name, default=_unset, untrusted=False):
        """parse a configuration element as a list of comma/space separated

        >>> u.configlist(s, b'list2')
        ['this', 'is', 'a small', 'test']
        """
        # default is not always a list
        v = self.configwith(
            config.parselist, section, name, default, 'list', untrusted
        )
        if isinstance(v, bytes):
            return config.parselist(v)
        elif v is None:
            return []

        >>> u.configdate(s, b'date')
        (0, 0)
        """
        if self.config(section, name, default, untrusted):
            return self.configwith(
                dateutil.parsedate, section, name, default, 'date', untrusted
            )
        if default is _unset:
            return None
        return default

        return section in self._data(untrusted)

    def configitems(self, section, untrusted=False, ignoresub=False):
        items = self._data(untrusted).items(section)
        if ignoresub:
            items = [i for i in items if ':' not in i[0]]
        if self.debugflag and not untrusted and self._reportuntrusted:
            for k, v in self._ucfg.items(section):
                if self._tcfg.get(section, k) != v:
                    self.debug(
                        "ignoring untrusted configuration option "
                        "%s.%s = %s\n" % (section, k, v)
                    )
        return items

    def walkconfig(self, untrusted=False):
        cfg = self._data(untrusted)

        - False if HGPLAIN is not set, or feature is in HGPLAINEXCEPT
        - False if feature is disabled by default and not included in HGPLAIN
        - True otherwise
        '''
        if (
            'HGPLAIN' not in encoding.environ
            and 'HGPLAINEXCEPT' not in encoding.environ
        ):
            return False
        exceptions = (
            encoding.environ.get('HGPLAINEXCEPT', '').strip().split(',')
        )
        # TODO: add support for HGPLAIN=+feature,-feature syntax
        if '+strictflags' not in encoding.environ.get('HGPLAIN', '').split(','):
            exceptions.append('strictflags')
        if feature and exceptions:
            return feature not in exceptions
        return True

    def username(self, acceptempty=False):

        If not found and acceptempty is True, returns None.
        If not found and ui.askusername is True, ask the user, else use
        ($LOGNAME or $USER or $LNAME or $USERNAME) + "@full.hostname".
        If no username could be found, raise an Abort error.
        """
        user = encoding.environ.get("HGUSER")
        if user is None:
            user = self.config("ui", "username")
            if user is not None:
                user = os.path.expandvars(user)
        if user is None:
            user = encoding.environ.get("EMAIL")
        if user is None and acceptempty:
            return user
        if user is None and self.configbool("ui", "askusername"):
            user = self.prompt(_("enter a commit username:"), default=None)
        if user is None and not self.interactive():
            try:
                user = '%s@%s' % (
                    procutil.getuser(),
                    encoding.strtolocal(socket.getfqdn()),
                )
                self.warn(_("no username found, using '%s' instead\n") % user)
            except KeyError:
                pass
        if not user:
            raise error.Abort(
                _('no username supplied'),
                hint=_("use 'hg config --edit' " 'to set your username'),
            )
        if "\n" in user:
            raise error.Abort(
                _("username %r contains a newline\n") % pycompat.bytestr(user)
            )
        return user

    def shortuser(self, user):
        """Return a short representation of a user name or email address."""

        if self._bufferstates:
            self._bufferapplylabels = self._bufferstates[-1][2]
        else:
            self._bufferapplylabels = None

        return "".join(self._buffers.pop())

    def _isbuffered(self, dest):
        if dest is self._fout:
            return bool(self._buffers)
        if dest is self._ferr:

        return self._colormode is None

    def canbatchlabeledwrites(self):
        '''check if write calls with labels are batchable'''
        # Windows color printing is special, see ``write``.
        return self._colormode != 'win32'

    def write(self, *args, **opts):
        '''write args to output

        By default, this method simply writes to the buffer or stdout.

        '''
        dest = self._fout

        # inlined _write() for speed
        if self._buffers:
            label = opts.get(r'label', '')
            if label and self._bufferapplylabels:
                self._buffers[-1].extend(self.label(a, label) for a in args)
            else:
                self._buffers[-1].extend(args)
            return

        msg = b''.join(args)

        # opencode timeblockedsection because this is a critical path
        starttime = util.timer()
        try:
            if self._colormode == 'win32':
                # windows color printing is its own can of crab, defer to
                # the color module and that is it.
                color.win32print(self, dest.write, msg, **opts)
            else:
                if self._colormode is not None:
                    label = opts.get(r'label', '')
                    msg = self.label(msg, label)
                dest.write(msg)
        except IOError as err:
            raise error.StdioError(err)
        finally:
            self._blockedtimes['stdio_blocked'] += (
                util.timer() - starttime
            ) * 1000

    def write_err(self, *args, **opts):
        self._write(self._ferr, *args, **opts)

    def _write(self, dest, *args, **opts):
        # update write() as well if you touch this code
        if self._isbuffered(dest):
            label = opts.get(r'label', '')
            if label and self._bufferapplylabels:
                self._buffers[-1].extend(self.label(a, label) for a in args)
            else:
                self._buffers[-1].extend(args)
        else:

                self._fout.flush()
            if getattr(dest, 'structured', False):
                # channel for machine-readable output with metadata, where
                # no extra colorization is necessary.
                dest.write(msg, **opts)
            elif self._colormode == 'win32':
                # windows color printing is its own can of crab, defer to
                # the color module and that is it.
                color.win32print(self, dest.write, msg, **opts)
            else:
                if self._colormode is not None:
                    label = opts.get(r'label', '')
                    msg = self.label(msg, label)
                dest.write(msg)
            # stderr may be buffered under win32 when redirected to files,
            # including stdout.
            if dest is self._ferr and not getattr(self._ferr, 'closed', False):

            ):
                # no way to report the error, so ignore it
                return
            raise error.StdioError(err)
        finally:
            self._blockedtimes['stdio_blocked'] += (
                util.timer() - starttime
            ) * 1000

    def _writemsg(self, dest, *args, **opts):
        _writemsgwith(self._write, dest, *args, **opts)

                    self._ferr.flush()
                except IOError as err:
                    if err.errno not in (errno.EPIPE, errno.EIO, errno.EBADF):
                        raise error.StdioError(err)
        finally:
            self._blockedtimes['stdio_blocked'] += (
                util.timer() - starttime
            ) * 1000

    def _isatty(self, fh):
        if self.configbool('ui', 'nontty'):
            return False
        return procutil.isatty(fh)

    def protectfinout(self):
        """Duplicate ui streams and redirect original if they are stdio

        """
        if self._disablepager or self.pageractive:
            # how pager should do is already determined
            return

        if not command.startswith('internal-always-') and (
            # explicit --pager=on (= 'internal-always-' prefix) should
            # take precedence over disabling factors below
            command in self.configlist('pager', 'ignore')
            or not self.configbool('ui', 'paginate')
            or not self.configbool('pager', 'attend-' + command, True)
            or encoding.environ.get('TERM') == 'dumb'
            # TODO: if we want to allow HGPLAINEXCEPT=pager,
            # formatted() will need some adjustment.
            or not self.formatted()
            or self.plain()
            or self._buffers
            # TODO: expose debugger-enabled on the UI object
            or '--debugger' in pycompat.sysargv
        ):
            # We only want to paginate if the ui appears to be
            # interactive, the user didn't say HGPLAIN or
            # HGPLAINEXCEPT=pager, and the user didn't specify --debug.
            return

        pagercmd = self.config('pager', 'pager', rcutil.fallbackpager)
        if not pagercmd:
            return

        pagerenv = {}
        for name, value in rcutil.defaultpagerenv().items():
            if name not in encoding.environ:
                pagerenv[name] = value

        self.debug(
            'starting pager for command %s\n' % stringutil.pprint(command)
        )
        self.flush()

        wasformatted = self.formatted()
        if util.safehasattr(signal, "SIGPIPE"):
            signal.signal(signal.SIGPIPE, _catchterm)
        if self._runpager(pagercmd, pagerenv):
            self.pageractive = True
            # Preserve the formatted-ness of the UI. This is important
            # because we mess with stdout, which might confuse
            # auto-detection of things being formatted.
            self.setconfig('ui', 'formatted', wasformatted, 'pager')
            self.setconfig('ui', 'interactive', False, 'pager')

            # If pagermode differs from color.mode, reconfigure color now that
            # pageractive is set.
            cm = self._colormode
            if cm != self.config('color', 'pagermode', cm):
                color.setup(self)
        else:
            # If the pager can't be spawned in dispatch when --pager=on is
            # given, don't try again when the command runs, to avoid a duplicate
            # warning about a missing pager command.

        """Actually start the pager and set up file descriptors.

        This is separate in part so that extensions (like chg) can
        override how a pager is invoked.
        """
        if command == 'cat':
            # Save ourselves some work.
            return False
        # If the command doesn't contain any of these characters, we
        # assume it's a binary and exec it directly. This means for
        # simple pager command configurations, we can degrade
        # gracefully and tell the user about their broken pager.
        shell = any(c in command for c in "|&;<>()$`\\\"' \t\n*?[#~=%")

        if pycompat.iswindows and not shell:
            # Window's built-in `more` cannot be invoked with shell=False, but
            # its `more.com` can.  Hide this implementation detail from the
            # user so we can also get sane bad PAGER behavior.  MSYS has
            # `more.exe`, so do a cmd.exe style resolution of the executable to
            # determine which one to use.
            fullcmd = procutil.findexe(command)
            if not fullcmd:
                self.warn(
                    _("missing pager command '%s', skipping pager\n") % command
                )
                return False

            command = fullcmd

                env=procutil.tonativeenv(procutil.shellenviron(env)),
            )
        except OSError as e:
            if e.errno == errno.ENOENT and not shell:
                self.warn(
                    _("missing pager command '%s', skipping pager\n") % command
                )
                return False
            raise

        # back up original file descriptors

        if self._isatty(procutil.stderr):
            os.dup2(pager.stdin.fileno(), procutil.stderr.fileno())

        @self.atexit
        def killpager():
            if util.safehasattr(signal, "SIGINT"):
                signal.signal(signal.SIGINT, signal.SIG_IGN)
            # restore original fds, closing pager.stdin copies in the process
            os.dup2(stdoutfd, procutil.stdout.fileno())
            os.dup2(stderrfd, procutil.stderr.fileno())
            pager.stdin.close()

        ui.interface.histedit = text

        Then histedit will use the text interface and chunkselector will use
        the default curses interface (crecord at the moment).
        """
        alldefaults = frozenset(["text", "curses"])

        featureinterfaces = {
            "chunkselector": ["text", "curses",],
            "histedit": ["text", "curses",],
        }

        # Feature-specific interface
        if feature not in featureinterfaces.keys():
            # Programming error, not user error
            raise ValueError("Unknown feature requested %s" % feature)

        availableinterfaces = frozenset(featureinterfaces[feature])
        if alldefaults > availableinterfaces:
            # Programming error, not user error. We need a use case to
            # define the right thing to do here.
            raise ValueError(
                "Feature %s does not handle all default interfaces" % feature
            )

        if self.plain() or encoding.environ.get('TERM') == 'dumb':
            return "text"

        # Default interface for all the features
        defaultinterface = "text"
        i = self.config("ui", "interface")
        if i in alldefaults:
            defaultinterface = i

        choseninterface = defaultinterface
        f = self.config("ui", "interface.%s" % feature)
        if f in availableinterfaces:
            choseninterface = f

        if i is not None and defaultinterface != i:
            if f is not None:
                self.warn(_("invalid value for ui.interface: %s\n") % (i,))
            else:
                self.warn(
                    _("invalid value for ui.interface: %s (using %s)\n")
                    % (i, choseninterface)
                )
        if f is not None and choseninterface != f:
            self.warn(
                _("invalid value for ui.interface.%s: %s (using %s)\n")
                % (feature, f, choseninterface)
            )

        return choseninterface

        configuration variable or - if it is unset - when `sys.stdin' points
        to a terminal device.

        This function refers to input only; for output, see `ui.formatted()'.
        '''
        i = self.configbool("ui", "interactive")
        if i is None:
            # some environments replace stdin without implementing isatty
            # usually those are non-interactive
            return self._isatty(self._fin)

        return i

    def termwidth(self):
        '''how wide is the terminal in columns?
        '''
        if 'COLUMNS' in encoding.environ:
            try:
                return int(encoding.environ['COLUMNS'])
            except ValueError:
                pass
        return scmutil.termsize(self)[0]

    def formatted(self):

        This function always returns false when in plain mode, see `ui.plain()'.
        '''
        if self.plain():
            return False

        i = self.configbool("ui", "formatted")
        if i is None:
            # some environments replace stdout without implementing isatty
            # usually those are non-interactive
            return self._isatty(self._fout)

        return i

    def _readline(self, prompt=' ', promptopts=None):
        # Replacing stdin/stdout temporarily is a hard problem on Python 3
        # because they have to be text streams with *no buffering*. Instead,
        # we use rawinput() only if call_readline() will be invoked by
        # PyOS_Readline(), so no I/O will be made at Python layer.
        usereadline = (

                readline.read_history_file
                # windows sometimes raises something other than ImportError
            except Exception:
                usereadline = False

        if self._colormode == 'win32' or not usereadline:
            if not promptopts:
                promptopts = {}
            self._writemsgnobuf(
                self._fmsgout, prompt, type='prompt', **promptopts
            )
            self.flush()
            prompt = ' '
        else:
            prompt = self.label(prompt, 'ui.prompt') + ' '

        # prompt ' ' must exist; otherwise readline may delete entire line
        # - http://bugs.python.org/issue12833
        with self.timeblockedsection('stdio'):
            if usereadline:
                line = encoding.strtolocal(pycompat.rawinput(prompt))
                # When stdin is in binary mode on Windows, it can cause
                # raw_input() to emit an extra trailing carriage return
                if pycompat.oslinesep == b'\r\n' and line.endswith(b'\r'):

                    raise EOFError
                line = line.rstrip(pycompat.oslinesep)

        return line

    def prompt(self, msg, default="y"):
        """Prompt user with msg, read response.
        If ui is not interactive, the default is returned.
        """
        return self._prompt(msg, default=default)

    def _prompt(self, msg, **opts):
        default = opts[r'default']
        if not self.interactive():
            self._writemsg(self._fmsgout, msg, ' ', type='prompt', **opts)
            self._writemsg(
                self._fmsgout, default or '', "\n", type='promptecho'
            )
            return default
        try:
            r = self._readline(prompt=msg, promptopts=opts)
            if not r:
                r = default
            if self.configbool('ui', 'promptecho'):
                self._writemsg(self._fmsgout, r, "\n", type='promptecho')
            return r
        except EOFError:
            raise error.ResponseExpected()

    @staticmethod

        # prompt to start parsing. Sadly, we also can't rely on
        # choices containing spaces, ASCII, or basically anything
        # except an ampersand followed by a character.
        m = re.match(br'(?s)(.+?)\$\$([^\$]*&[^ \$].*)', prompt)
        msg = m.group(1)
        choices = [p.strip(' ') for p in m.group(2).split('$$')]

        def choicetuple(s):
            ampidx = s.index('&')
            return s[ampidx + 1 : ampidx + 2].lower(), s.replace('&', '', 1)

        return (msg, [choicetuple(s) for s in choices])

    def promptchoice(self, prompt, default=0):
        """Prompt user with a message, read response, and ensure it matches

        while True:
            r = self._prompt(msg, default=resps[default], choices=choices)
            if r.lower() in resps:
                return resps.index(r.lower())
            # TODO: shouldn't it be a warning?
            self._writemsg(self._fmsgout, _("unrecognized response\n"))

    def getpass(self, prompt=None, default=None):
        if not self.interactive():
            return default
        try:
            self._writemsg(
                self._fmsgerr,
                prompt or _('password: '),
                type='prompt',
                password=True,
            )
            # disable getpass() only if explicitly specified. it's still valid
            # to interact with tty even if fin is not a tty.
            with self.timeblockedsection('stdio'):
                if self.configbool('ui', 'nontty'):
                    l = self._fin.readline()
                    if not l:
                        raise EOFError
                    return l.rstrip('\n')
                else:
                    return getpass.getpass(r'')
        except EOFError:
            raise error.ResponseExpected()

        '''write status message to output (if ui.quiet is False)

        This adds an output label of "ui.status".
        '''
        if not self.quiet:
            self._writemsg(self._fmsgout, type='status', *msg, **opts)

    def warn(self, *msg, **opts):
        '''write warning message to output (stderr)

        This adds an output label of "ui.warning".
        '''
        self._writemsg(self._fmsgerr, type='warning', *msg, **opts)

    def error(self, *msg, **opts):
        '''write error message to output (stderr)

        This adds an output label of "ui.error".
        '''
        self._writemsg(self._fmsgerr, type='error', *msg, **opts)

    def note(self, *msg, **opts):
        '''write note to output (if ui.verbose is True)

        This adds an output label of "ui.note".
        '''
        if self.verbose:
            self._writemsg(self._fmsgout, type='note', *msg, **opts)

    def debug(self, *msg, **opts):
        '''write debug message to output (if ui.debugflag is True)

        This adds an output label of "ui.debug".
        '''
        if self.debugflag:
            self._writemsg(self._fmsgout, type='debug', *msg, **opts)
            self.log(b'debug', b'%s', b''.join(msg))

    def edit(
        self,
        text,

        repopath=None,
        action=None,
    ):
        if action is None:
            self.develwarn(
                'action is None but will soon be a required '
                'parameter to ui.edit()'
            )
        extra_defaults = {
            'prefix': 'editor',
            'suffix': '.txt',
        }
        if extra is not None:
            if extra.get('suffix') is not None:
                self.develwarn(
                    'extra.suffix is not None but will soon be '
                    'ignored by ui.edit()'
                )
            extra_defaults.update(extra)
        extra = extra_defaults

        if action == 'diff':
            suffix = '.diff'
        elif action:
            suffix = '.%s.hg.txt' % action
        else:
            suffix = extra['suffix']

        rdir = None
        if self.configbool('experimental', 'editortmpinhg'):
            rdir = repopath
        (fd, name) = pycompat.mkstemp(
            prefix='hg-' + extra['prefix'] + '-', suffix=suffix, dir=rdir
        )
        try:
            f = os.fdopen(fd, r'wb')
            f.write(util.tonativeeol(text))
            f.close()

            environ = {'HGUSER': user}
            if 'transplant_source' in extra:
                environ.update({'HGREVISION': hex(extra['transplant_source'])})
            for label in ('intermediate-source', 'source', 'rebase_source'):
                if label in extra:
                    environ.update({'HGREVISION': extra[label]})
                    break
            if editform:
                environ.update({'HGEDITFORM': editform})
            if pending:
                environ.update({'HG_PENDING': pending})

            editor = self.geteditor()

            self.system(
                "%s \"%s\"" % (editor, name),
                environ=environ,
                onerr=error.Abort,
                errprefix=_("edit failed"),
                blockedtag='editor',
            )

            f = open(name, r'rb')
            t = util.fromnativeeol(f.read())
            f.close()

        '''
        if blockedtag is None:
            # Long cmds tend to be because of an absolute path on cmd. Keep
            # the tail end instead
            cmdsuffix = cmd.translate(None, _keepalnum)[-85:]
            blockedtag = 'unknown_system_' + cmdsuffix
        out = self._fout
        if any(s[1] for s in self._bufferstates):
            out = self
        with self.timeblockedsection(blockedtag):
            rc = self._runsystem(cmd, environ=environ, cwd=cwd, out=out)
        if rc and onerr:
            errmsg = '%s %s' % (
                os.path.basename(cmd.split(None, 1)[0]),
                procutil.explainexit(rc),
            )
            if errprefix:
                errmsg = '%s: %s' % (errprefix, errmsg)
            raise onerr(errmsg)
        return rc

    def _runsystem(self, cmd, environ, cwd, out):
        """actually execute the given shell command (can be overridden by

                exctb = traceback.format_tb(exc[2])
                exconly = traceback.format_exception_only(cause[0], cause[1])

                # exclude frame where 'exc' was chained and rethrown from exctb
                self.write_err(
                    'Traceback (most recent call last):\n',
                    ''.join(exctb[:-1]),
                    ''.join(causetb),
                    ''.join(exconly),
                )
            else:
                output = traceback.format_exception(exc[0], exc[1], exc[2])
                self.write_err(encoding.strtolocal(r''.join(output)))
        return self.tracebackflag or force

    def geteditor(self):
        '''return editor to use'''
        if pycompat.sysplatform == 'plan9':
            # vi is the MIPS instruction simulator on Plan 9. We
            # instead default to E to plumb commit messages to
            # avoid confusion.
            editor = 'E'
        else:
            editor = 'vi'
        return encoding.environ.get("HGEDITOR") or self.config(
            "ui", "editor", editor
        )

    @util.propertycache
    def _progbar(self):
        """setup the progbar singleton to the ui object"""
        if (
            self.quiet
            or self.debugflag
            or self.configbool('progress', 'disable')
            or not progress.shouldprint(self)
        ):
            return None
        return getprogbar(self)

        if not haveprogbar():  # nothing loaded yet
            return
        if self._progbar is not None and self._progbar.printed:
            self._progbar.clear()

    def progress(self, topic, pos, item="", unit="", total=None):
        '''show a progress message

        By default a textual progress bar will be displayed if an operation
        takes too long. 'topic' is the current operation, 'item' is a
        non-numeric marker of the current position (i.e. the currently

        Multiple nested topics may be active at a time.

        All topics should be marked closed by setting pos to None at
        termination.
        '''
        self.deprecwarn("use ui.makeprogress() instead of ui.progress()", "5.1")
        progress = self.makeprogress(topic, unit, total)
        if pos is not None:
            progress.update(pos, item=item)
        else:
            progress.complete()

    def makeprogress(self, topic, unit="", total=None):
        """Create a progress helper for the specified topic"""
        if getattr(self._fmsgerr, 'structured', False):
            # channel for machine-readable output with metadata, just send
            # raw information
            # TODO: consider porting some useful information (e.g. estimated

        """issue a developer warning message

        Use 'stacklevel' to report the offender some layers further up in the
        stack.
        """
        if not self.configbool('devel', 'all-warnings'):
            if config is None or not self.configbool('devel', config):
                return
        msg = 'devel-warn: ' + msg
        stacklevel += 1  # get in develwarn
        if self.tracebackflag:
            util.debugstacktrace(msg, stacklevel, self._ferr, self._fout)
            self.log(
                'develwarn',
                '%s at:\n%s' % (msg, ''.join(util.getstackframes(stacklevel))),
            )
        else:
            curframe = inspect.currentframe()
            calframe = inspect.getouterframes(curframe, 2)
            fname, lineno, fmsg = calframe[stacklevel][1:4]
            fname, fmsg = pycompat.sysbytes(fname), pycompat.sysbytes(fmsg)
            self.write_err('%s at: %s:%d (%s)\n' % (msg, fname, lineno, fmsg))
            self.log(
                'develwarn', '%s at: %s:%d (%s)\n', msg, fname, lineno, fmsg
            )
            curframe = calframe = None  # avoid cycles

    def deprecwarn(self, msg, version, stacklevel=2):
        """issue a deprecation warning

        - msg: message explaining what is deprecated and how to upgrade,
        - version: last version where the API will be supported,
        """
        if not (
            self.configbool('devel', 'all-warnings')
            or self.configbool('devel', 'deprec-warn')
        ):
            return
        msg += (
            "\n(compatibility will be dropped after Mercurial-%s,"
            " update your code.)"
        ) % version
        self.develwarn(msg, stacklevel=stacklevel, config='deprec-warn')

    def exportableenviron(self):
        """The environment variables that are safe to export, e.g. through
        hgweb.
        """
        return self._exportableenviron

    @contextlib.contextmanager
    def configoverride(self, overrides, source=""):
        """Context manager for temporary config overrides
        `overrides` must be a dict of the following structure:
        {(section, name) : value}"""
        backups = {}
        try:

        finally:
            for __, backup in backups.items():
                self.restoreconfig(backup)
            # just restoring ui.quiet config to the previous value is not enough
            # as it does not update ui.quiet class member
            if ('ui', 'quiet') in overrides:
                self.fixconfig(section='ui')


class paths(dict):
    """Represents a collection of paths and their configs.

    """

    def __init__(self, ui):
        dict.__init__(self)

        for name, loc in ui.configitems('paths', ignoresub=True):
            # No location is the same as not existing.
            if not loc:
                continue
            loc, sub = ui.configsuboptions('paths', name)
            self[name] = path(ui, name, rawloc=loc, suboptions=sub)

    def getpath(self, name, default=None):
        """Return a ``path`` from a string, falling back to default.

            # Try to resolve as a local path or URI.
            try:
                # We don't pass sub-options in, so no need to pass ui instance.
                return path(None, None, rawloc=name)
            except ValueError:
                raise error.RepoError(_('repository %s does not exist') % name)


_pathsuboptions = {}

        return func

    return register


@pathsuboption('pushurl', 'pushloc')
def pushurlpathoption(ui, path, value):
    u = util.url(value)
    # Actually require a URL.
    if not u.scheme:
        ui.warn(_('(paths.%s:pushurl not a URL; ignoring)\n') % path.name)
        return None

    # Don't support the #foo syntax in the push URL to declare branch to
    # push.
    if u.fragment:
        ui.warn(
            _('("#fragment" in paths.%s:pushurl not supported; ' 'ignoring)\n')
            % path.name
        )
        u.fragment = None

    return bytes(u)


@pathsuboption('pushrev', 'pushrev')
def pushrevpathoption(ui, path, value):
    return value


class path(object):

        If ``name`` is not defined, we require that the location be a) a local
        filesystem path with a .hg directory or b) a URL. If not,
        ``ValueError`` is raised.
        """
        if not rawloc:
            raise ValueError('rawloc must be defined')

        # Locations may define branches via syntax <base>#<branch>.
        u = util.url(rawloc)
        branch = None
        if u.fragment:

        self.url = u
        self.branch = branch

        self.name = name
        self.rawloc = rawloc
        self.loc = '%s' % u

        # When given a raw location but not a symbolic name, validate the
        # location is valid.
        if not name and not u.scheme and not self._isvalidlocalpath(self.loc):
            raise ValueError(
                'location is not a URL or path to a local ' 'repo: %s' % rawloc
            )

        suboptions = suboptions or {}

        # Now process the sub-options. If a sub-option is registered, its

        """Returns True if the given path is a potentially valid repository.
        This is its own function so that extensions can change the definition of
        'valid' in this case (like when pulling from a git repo into a hg
        one)."""
        try:
            return os.path.isdir(os.path.join(path, '.hg'))
        # Python 2 may return TypeError. Python 3, ValueError.
        except (TypeError, ValueError):
            return False

    @property

    The specified message type is translated to 'ui.<type>' label if the dest
    isn't a structured channel, so that the message will be colorized.
    """
    # TODO: maybe change 'type' to a mandatory option
    if r'type' in opts and not getattr(dest, 'structured', False):
        opts[r'label'] = opts.get(r'label', '') + ' ui.%s' % opts.pop(r'type')
    write(dest, *args, **opts)

43077:687b865b95ad

)

urlreq = util.urlreq

# for use with str.translate(None, _keepalnum), to keep just alphanumerics
_keepalnum = b''.join(
    c for c in map(pycompat.bytechr, range(256)) if not c.isalnum()
)

# The config knobs that will be altered (if unset) by ui.tweakdefaults.
tweakrc = b"""

showfunc = 1
word-diff = 1
"""

samplehgrcs = {
    b'user': b"""# example user config (see 'hg help config' for more info)
[ui]
# name and email, e.g.
# username = Jane Doe <[e-mail]>
username =

#
# histedit =
# rebase =
# uncommit =
""",
    b'cloned': b"""# example repository config (see 'hg help config' for more info)
[paths]
default = %s

# path aliases to other clones of this repo in URLs or filesystem paths
# (see 'hg help config.paths' for more info)

[ui]
# name and email (local to this repository, optional), e.g.
# username = Jane Doe <[e-mail]>
""",
    b'local': b"""# example repository config (see 'hg help config' for more info)
[paths]
# path aliases to other clones of this repo in URLs or filesystem paths
# (see 'hg help config.paths' for more info)
#
# default         = http://example.com/hg/example-repo

[ui]
# name and email (local to this repository, optional), e.g.
# username = Jane Doe <[e-mail]>
""",
    b'global': b"""# example system-wide hg config (see 'hg help config' for more info)

[ui]
# uncomment to disable color in command output
# (see 'hg help color' for details)
# color = never

            self.environ = encoding.environ

            self.httppasswordmgrdb = httppasswordmgrdbproxy()
            self._blockedtimes = collections.defaultdict(int)

        allowed = self.configlist(b'experimental', b'exportableenviron')
        if b'*' in allowed:
            self._exportableenviron = self.environ
        else:
            self._exportableenviron = {}
            for k in allowed:
                if k in self.environ:

    def load(cls):
        """Create a ui and load global and user configs"""
        u = cls()
        # we always trust global config files and environment variables
        for t, f in rcutil.rccomponents():
            if t == b'path':
                u.readconfig(f, trust=True)
            elif t == b'items':
                sections = set()
                for section, name, value, source in f:
                    # do not set u._ocfg
                    # XXX clean this up once immutable config object is a thing
                    u._tcfg.set(section, name, value, source)
                    u._ucfg.set(section, name, value, source)
                    sections.add(section)
                for section in sections:
                    u.fixconfig(section=section)
            else:
                raise error.ProgrammingError(b'unknown rctype: %s' % t)
        u._maybetweakdefaults()
        return u

    def _maybetweakdefaults(self):
        if not self.configbool(b'ui', b'tweakdefaults'):
            return
        if self._tweaked or self.plain(b'tweakdefaults'):
            return

        # Note: it is SUPER IMPORTANT that you set self._tweaked to
        # True *before* any calls to setconfig(), otherwise you'll get
        # infinite recursion between setconfig and this method.
        #
        # TODO: We should extract an inner method in setconfig() to
        # avoid this weirdness.
        self._tweaked = True
        tmpcfg = config.config()
        tmpcfg.parse(b'<tweakdefaults>', tweakrc)
        for section in tmpcfg:
            for name, value in tmpcfg.items(section):
                if not self.hasconfig(section, name):
                    self.setconfig(section, name, value, b"<tweakdefaults>")

    def copy(self):
        return self.__class__(self)

    def resetstate(self):

        # this is open-coded below - search for timeblockedsection to find them
        starttime = util.timer()
        try:
            yield
        finally:
            self._blockedtimes[key + b'_blocked'] += (
                util.timer() - starttime
            ) * 1000

    @contextlib.contextmanager
    def uninterruptible(self):

        Most operations on a repository are safe to interrupt, but a
        few are risky (for example repair.strip). This context manager
        lets you advise Mercurial that something risky is happening so
        that control-C etc can be blocked if desired.
        """
        enabled = self.configbool(b'experimental', b'nointerrupt')
        if enabled and self.configbool(
            b'experimental', b'nointerrupt-interactiveonly'
        ):
            enabled = self.interactive()
        if self._uninterruptible or not enabled:
            # if nointerrupt support is turned off, the process isn't
            # interactive, or we're already in an uninterruptible
            # block, do nothing.
            yield
            return

        def warn():
            self.warn(_(b"shutting down cleanly\n"))
            self.warn(
                _(b"press ^C again to terminate immediately (dangerous)\n")
            )
            return True

        with procutil.uninterruptible(warn):
            try:

        st = util.fstat(fp)
        if util.isowner(st):
            return True

        tusers, tgroups = self._trustusers, self._trustgroups
        if b'*' in tusers or b'*' in tgroups:
            return True

        user = util.username(st.st_uid)
        group = util.groupname(st.st_gid)
        if user in tusers or group in tgroups or user == util.username():
            return True

        if self._reportuntrusted:
            self.warn(
                _(
                    b'not trusting file %s from untrusted '
                    b'user %s, group %s\n'
                )
                % (f, user, group)
            )
        return False

    def readconfig(

            cfg.read(filename, fp, sections=sections, remap=remap)
            fp.close()
        except error.ConfigError as inst:
            if trusted:
                raise
            self.warn(_(b"ignored: %s\n") % stringutil.forcebytestr(inst))

        if self.plain():
            for k in (
                b'debug',
                b'fallbackencoding',
                b'quiet',
                b'slash',
                b'logtemplate',
                b'message-output',
                b'statuscopies',
                b'style',
                b'traceback',
                b'verbose',
            ):
                if k in cfg[b'ui']:
                    del cfg[b'ui'][k]
            for k, v in cfg.items(b'defaults'):
                del cfg[b'defaults'][k]
            for k, v in cfg.items(b'commands'):
                del cfg[b'commands'][k]
        # Don't remove aliases from the configuration if in the exceptionlist
        if self.plain(b'alias'):
            for k, v in cfg.items(b'alias'):
                del cfg[b'alias'][k]
        if self.plain(b'revsetalias'):
            for k, v in cfg.items(b'revsetalias'):
                del cfg[b'revsetalias'][k]
        if self.plain(b'templatealias'):
            for k, v in cfg.items(b'templatealias'):
                del cfg[b'templatealias'][k]

        if trusted:
            self._tcfg.update(cfg)
            self._tcfg.update(self._ocfg)
        self._ucfg.update(cfg)
        self._ucfg.update(self._ocfg)

        if root is None:
            root = os.path.expanduser(b'~')
        self.fixconfig(root=root)

    def fixconfig(self, root=None, section=None):
        if section in (None, b'paths'):
            # expand vars and ~
            # translate paths relative to root (or home) into absolute paths
            root = root or encoding.getcwd()
            for c in self._tcfg, self._ucfg, self._ocfg:
                for n, p in c.items(b'paths'):
                    # Ignore sub-options.
                    if b':' in n:
                        continue
                    if not p:
                        continue
                    if b'%%' in p:
                        s = self.configsource(b'paths', n) or b'none'
                        self.warn(
                            _(b"(deprecated '%%' in path %s=%s from %s)\n")
                            % (n, p, s)
                        )
                        p = p.replace(b'%%', b'%')
                    p = util.expandpath(p)
                    if not util.hasscheme(p) and not os.path.isabs(p):
                        p = os.path.normpath(os.path.join(root, p))
                    c.set(b"paths", n, p)

        if section in (None, b'ui'):
            # update ui options
            self._fmsgout, self._fmsgerr = _selectmsgdests(self)
            self.debugflag = self.configbool(b'ui', b'debug')
            self.verbose = self.debugflag or self.configbool(b'ui', b'verbose')
            self.quiet = not self.debugflag and self.configbool(b'ui', b'quiet')
            if self.verbose and self.quiet:
                self.quiet = self.verbose = False
            self._reportuntrusted = self.debugflag or self.configbool(
                b"ui", b"report_untrusted"
            )
            self.tracebackflag = self.configbool(b'ui', b'traceback')
            self.logblockedtimes = self.configbool(b'ui', b'logblockedtimes')

        if section in (None, b'trusted'):
            # update trust information
            self._trustusers.update(self.configlist(b'trusted', b'users'))
            self._trustgroups.update(self.configlist(b'trusted', b'groups'))

        if section in (None, b'devel', b'ui') and self.debugflag:
            tracked = set()
            if self.configbool(b'devel', b'debug.extensions'):
                tracked.add(b'extension')

    def restoreconfig(self, data):
        self._ocfg.restore(data[0])
        self._tcfg.restore(data[1])
        self._ucfg.restore(data[2])

    def setconfig(self, section, name, value, source=b''):
        for cfg in (self._ocfg, self._tcfg, self._ucfg):
            cfg.set(section, name, value, source)
        self.fixconfig(section=section)
        self._maybetweakdefaults()

            if callable(item.default):
                itemdefault = item.default()
            else:
                itemdefault = item.default
        else:
            msg = b"accessing unregistered config item: '%s.%s'"
            msg %= (section, name)
            self.develwarn(msg, 2, b'warn-config-unknown')

        if default is _unset:
            if item is None:
                value = default
            elif item.default is configitems.dynamicdefault:
                value = None
                msg = b"config item requires an explicit default value: '%s.%s'"
                msg %= (section, name)
                self.develwarn(msg, 2, b'warn-config-default')
            else:
                value = itemdefault
        elif (
            item is not None
            and item.default is not configitems.dynamicdefault
            and default != itemdefault
        ):
            msg = (
                b"specifying a mismatched default value for a registered "
                b"config item: '%s.%s' '%s'"
            )
            msg %= (section, name, pycompat.bytestr(default))
            self.develwarn(msg, 2, b'warn-config-default')

        for s, n in alternates:
            candidate = self._data(untrusted).get(s, n, None)
            if candidate is not None:
                value = candidate

        if self.debugflag and not untrusted and self._reportuntrusted:
            for s, n in alternates:
                uvalue = self._ucfg.get(s, n)
                if uvalue is not None and uvalue != value:
                    self.debug(
                        b"ignoring untrusted configuration option "
                        b"%s.%s = %s\n" % (s, n, uvalue)
                    )
        return value

    def configsuboptions(self, section, name, default=_unset, untrusted=False):
        """Get a config option and all sub-options.

        is a dict of defined sub-options where keys and values are strings.
        """
        main = self.config(section, name, default, untrusted=untrusted)
        data = self._data(untrusted)
        sub = {}
        prefix = b'%s:' % name
        for k, v in data.items(section):
            if k.startswith(prefix):
                sub[k[len(prefix) :]] = v

        if self.debugflag and not untrusted and self._reportuntrusted:
            for k, v in sub.items():
                uvalue = self._ucfg.get(section, b'%s:%s' % (name, k))
                if uvalue is not None and uvalue != v:
                    self.debug(
                        b'ignoring untrusted configuration option '
                        b'%s:%s.%s = %s\n' % (section, name, k, uvalue)
                    )

        return main, sub

    def configpath(self, section, name, default=_unset, untrusted=False):
        b'get a path config item, expanded relative to repo root or config file'
        v = self.config(section, name, default, untrusted)
        if v is None:
            return None
        if not os.path.isabs(v) or b"://" not in v:
            src = self.configsource(section, name, untrusted)
            if b':' in src:
                base = os.path.dirname(src.rsplit(b':')[0])
                v = os.path.join(base, os.path.expanduser(v))
        return v

    def configbool(self, section, name, default=_unset, untrusted=False):
        """parse a configuration element as a boolean

        if isinstance(v, bool):
            return v
        b = stringutil.parsebool(v)
        if b is None:
            raise error.ConfigError(
                _(b"%s.%s is not a boolean ('%s')") % (section, name, v)
            )
        return b

    def configwith(
        self, convert, section, name, default=_unset, desc=None, untrusted=False

            return convert(v)
        except (ValueError, error.ParseError):
            if desc is None:
                desc = pycompat.sysbytes(convert.__name__)
            raise error.ConfigError(
                _(b"%s.%s is not a valid %s ('%s')") % (section, name, desc, v)
            )

    def configint(self, section, name, default=_unset, untrusted=False):
        """parse a configuration element as an integer

            ...
        ConfigError: foo.invalid is not a valid integer ('somevalue')
        """

        return self.configwith(
            int, section, name, default, b'integer', untrusted
        )

    def configbytes(self, section, name, default=_unset, untrusted=False):
        """parse a configuration element as a quantity in bytes

            return value
        try:
            return util.sizetoint(value)
        except error.ParseError:
            raise error.ConfigError(
                _(b"%s.%s is not a byte quantity ('%s')")
                % (section, name, value)
            )

    def configlist(self, section, name, default=_unset, untrusted=False):
        """parse a configuration element as a list of comma/space separated

        >>> u.configlist(s, b'list2')
        ['this', 'is', 'a small', 'test']
        """
        # default is not always a list
        v = self.configwith(
            config.parselist, section, name, default, b'list', untrusted
        )
        if isinstance(v, bytes):
            return config.parselist(v)
        elif v is None:
            return []

        >>> u.configdate(s, b'date')
        (0, 0)
        """
        if self.config(section, name, default, untrusted):
            return self.configwith(
                dateutil.parsedate, section, name, default, b'date', untrusted
            )
        if default is _unset:
            return None
        return default

        return section in self._data(untrusted)

    def configitems(self, section, untrusted=False, ignoresub=False):
        items = self._data(untrusted).items(section)
        if ignoresub:
            items = [i for i in items if b':' not in i[0]]
        if self.debugflag and not untrusted and self._reportuntrusted:
            for k, v in self._ucfg.items(section):
                if self._tcfg.get(section, k) != v:
                    self.debug(
                        b"ignoring untrusted configuration option "
                        b"%s.%s = %s\n" % (section, k, v)
                    )
        return items

    def walkconfig(self, untrusted=False):
        cfg = self._data(untrusted)

        - False if HGPLAIN is not set, or feature is in HGPLAINEXCEPT
        - False if feature is disabled by default and not included in HGPLAIN
        - True otherwise
        '''
        if (
            b'HGPLAIN' not in encoding.environ
            and b'HGPLAINEXCEPT' not in encoding.environ
        ):
            return False
        exceptions = (
            encoding.environ.get(b'HGPLAINEXCEPT', b'').strip().split(b',')
        )
        # TODO: add support for HGPLAIN=+feature,-feature syntax
        if b'+strictflags' not in encoding.environ.get(b'HGPLAIN', b'').split(
            b','
        ):
            exceptions.append(b'strictflags')
        if feature and exceptions:
            return feature not in exceptions
        return True

    def username(self, acceptempty=False):

        If not found and acceptempty is True, returns None.
        If not found and ui.askusername is True, ask the user, else use
        ($LOGNAME or $USER or $LNAME or $USERNAME) + "@full.hostname".
        If no username could be found, raise an Abort error.
        """
        user = encoding.environ.get(b"HGUSER")
        if user is None:
            user = self.config(b"ui", b"username")
            if user is not None:
                user = os.path.expandvars(user)
        if user is None:
            user = encoding.environ.get(b"EMAIL")
        if user is None and acceptempty:
            return user
        if user is None and self.configbool(b"ui", b"askusername"):
            user = self.prompt(_(b"enter a commit username:"), default=None)
        if user is None and not self.interactive():
            try:
                user = b'%s@%s' % (
                    procutil.getuser(),
                    encoding.strtolocal(socket.getfqdn()),
                )
                self.warn(_(b"no username found, using '%s' instead\n") % user)
            except KeyError:
                pass
        if not user:
            raise error.Abort(
                _(b'no username supplied'),
                hint=_(b"use 'hg config --edit' " b'to set your username'),
            )
        if b"\n" in user:
            raise error.Abort(
                _(b"username %r contains a newline\n") % pycompat.bytestr(user)
            )
        return user

    def shortuser(self, user):
        """Return a short representation of a user name or email address."""

        if self._bufferstates:
            self._bufferapplylabels = self._bufferstates[-1][2]
        else:
            self._bufferapplylabels = None

        return b"".join(self._buffers.pop())

    def _isbuffered(self, dest):
        if dest is self._fout:
            return bool(self._buffers)
        if dest is self._ferr:

        return self._colormode is None

    def canbatchlabeledwrites(self):
        '''check if write calls with labels are batchable'''
        # Windows color printing is special, see ``write``.
        return self._colormode != b'win32'

    def write(self, *args, **opts):
        '''write args to output

        By default, this method simply writes to the buffer or stdout.

        '''
        dest = self._fout

        # inlined _write() for speed
        if self._buffers:
            label = opts.get(r'label', b'')
            if label and self._bufferapplylabels:
                self._buffers[-1].extend(self.label(a, label) for a in args)
            else:
                self._buffers[-1].extend(args)
            return

        msg = b''.join(args)

        # opencode timeblockedsection because this is a critical path
        starttime = util.timer()
        try:
            if self._colormode == b'win32':
                # windows color printing is its own can of crab, defer to
                # the color module and that is it.
                color.win32print(self, dest.write, msg, **opts)
            else:
                if self._colormode is not None:
                    label = opts.get(r'label', b'')
                    msg = self.label(msg, label)
                dest.write(msg)
        except IOError as err:
            raise error.StdioError(err)
        finally:
            self._blockedtimes[b'stdio_blocked'] += (
                util.timer() - starttime
            ) * 1000

    def write_err(self, *args, **opts):
        self._write(self._ferr, *args, **opts)

    def _write(self, dest, *args, **opts):
        # update write() as well if you touch this code
        if self._isbuffered(dest):
            label = opts.get(r'label', b'')
            if label and self._bufferapplylabels:
                self._buffers[-1].extend(self.label(a, label) for a in args)
            else:
                self._buffers[-1].extend(args)
        else:

                self._fout.flush()
            if getattr(dest, 'structured', False):
                # channel for machine-readable output with metadata, where
                # no extra colorization is necessary.
                dest.write(msg, **opts)
            elif self._colormode == b'win32':
                # windows color printing is its own can of crab, defer to
                # the color module and that is it.
                color.win32print(self, dest.write, msg, **opts)
            else:
                if self._colormode is not None:
                    label = opts.get(r'label', b'')
                    msg = self.label(msg, label)
                dest.write(msg)
            # stderr may be buffered under win32 when redirected to files,
            # including stdout.
            if dest is self._ferr and not getattr(self._ferr, 'closed', False):

            ):
                # no way to report the error, so ignore it
                return
            raise error.StdioError(err)
        finally:
            self._blockedtimes[b'stdio_blocked'] += (
                util.timer() - starttime
            ) * 1000

    def _writemsg(self, dest, *args, **opts):
        _writemsgwith(self._write, dest, *args, **opts)

                    self._ferr.flush()
                except IOError as err:
                    if err.errno not in (errno.EPIPE, errno.EIO, errno.EBADF):
                        raise error.StdioError(err)
        finally:
            self._blockedtimes[b'stdio_blocked'] += (
                util.timer() - starttime
            ) * 1000

    def _isatty(self, fh):
        if self.configbool(b'ui', b'nontty'):
            return False
        return procutil.isatty(fh)

    def protectfinout(self):
        """Duplicate ui streams and redirect original if they are stdio

        """
        if self._disablepager or self.pageractive:
            # how pager should do is already determined
            return

        if not command.startswith(b'internal-always-') and (
            # explicit --pager=on (= 'internal-always-' prefix) should
            # take precedence over disabling factors below
            command in self.configlist(b'pager', b'ignore')
            or not self.configbool(b'ui', b'paginate')
            or not self.configbool(b'pager', b'attend-' + command, True)
            or encoding.environ.get(b'TERM') == b'dumb'
            # TODO: if we want to allow HGPLAINEXCEPT=pager,
            # formatted() will need some adjustment.
            or not self.formatted()
            or self.plain()
            or self._buffers
            # TODO: expose debugger-enabled on the UI object
            or b'--debugger' in pycompat.sysargv
        ):
            # We only want to paginate if the ui appears to be
            # interactive, the user didn't say HGPLAIN or
            # HGPLAINEXCEPT=pager, and the user didn't specify --debug.
            return

        pagercmd = self.config(b'pager', b'pager', rcutil.fallbackpager)
        if not pagercmd:
            return

        pagerenv = {}
        for name, value in rcutil.defaultpagerenv().items():
            if name not in encoding.environ:
                pagerenv[name] = value

        self.debug(
            b'starting pager for command %s\n' % stringutil.pprint(command)
        )
        self.flush()

        wasformatted = self.formatted()
        if util.safehasattr(signal, b"SIGPIPE"):
            signal.signal(signal.SIGPIPE, _catchterm)
        if self._runpager(pagercmd, pagerenv):
            self.pageractive = True
            # Preserve the formatted-ness of the UI. This is important
            # because we mess with stdout, which might confuse
            # auto-detection of things being formatted.
            self.setconfig(b'ui', b'formatted', wasformatted, b'pager')
            self.setconfig(b'ui', b'interactive', False, b'pager')

            # If pagermode differs from color.mode, reconfigure color now that
            # pageractive is set.
            cm = self._colormode
            if cm != self.config(b'color', b'pagermode', cm):
                color.setup(self)
        else:
            # If the pager can't be spawned in dispatch when --pager=on is
            # given, don't try again when the command runs, to avoid a duplicate
            # warning about a missing pager command.

        """Actually start the pager and set up file descriptors.

        This is separate in part so that extensions (like chg) can
        override how a pager is invoked.
        """
        if command == b'cat':
            # Save ourselves some work.
            return False
        # If the command doesn't contain any of these characters, we
        # assume it's a binary and exec it directly. This means for
        # simple pager command configurations, we can degrade
        # gracefully and tell the user about their broken pager.
        shell = any(c in command for c in b"|&;<>()$`\\\"' \t\n*?[#~=%")

        if pycompat.iswindows and not shell:
            # Window's built-in `more` cannot be invoked with shell=False, but
            # its `more.com` can.  Hide this implementation detail from the
            # user so we can also get sane bad PAGER behavior.  MSYS has
            # `more.exe`, so do a cmd.exe style resolution of the executable to
            # determine which one to use.
            fullcmd = procutil.findexe(command)
            if not fullcmd:
                self.warn(
                    _(b"missing pager command '%s', skipping pager\n") % command
                )
                return False

            command = fullcmd

                env=procutil.tonativeenv(procutil.shellenviron(env)),
            )
        except OSError as e:
            if e.errno == errno.ENOENT and not shell:
                self.warn(
                    _(b"missing pager command '%s', skipping pager\n") % command
                )
                return False
            raise

        # back up original file descriptors

        if self._isatty(procutil.stderr):
            os.dup2(pager.stdin.fileno(), procutil.stderr.fileno())

        @self.atexit
        def killpager():
            if util.safehasattr(signal, b"SIGINT"):
                signal.signal(signal.SIGINT, signal.SIG_IGN)
            # restore original fds, closing pager.stdin copies in the process
            os.dup2(stdoutfd, procutil.stdout.fileno())
            os.dup2(stderrfd, procutil.stderr.fileno())
            pager.stdin.close()

        ui.interface.histedit = text

        Then histedit will use the text interface and chunkselector will use
        the default curses interface (crecord at the moment).
        """
        alldefaults = frozenset([b"text", b"curses"])

        featureinterfaces = {
            b"chunkselector": [b"text", b"curses",],
            b"histedit": [b"text", b"curses",],
        }

        # Feature-specific interface
        if feature not in featureinterfaces.keys():
            # Programming error, not user error
            raise ValueError(b"Unknown feature requested %s" % feature)

        availableinterfaces = frozenset(featureinterfaces[feature])
        if alldefaults > availableinterfaces:
            # Programming error, not user error. We need a use case to
            # define the right thing to do here.
            raise ValueError(
                b"Feature %s does not handle all default interfaces" % feature
            )

        if self.plain() or encoding.environ.get(b'TERM') == b'dumb':
            return b"text"

        # Default interface for all the features
        defaultinterface = b"text"
        i = self.config(b"ui", b"interface")
        if i in alldefaults:
            defaultinterface = i

        choseninterface = defaultinterface
        f = self.config(b"ui", b"interface.%s" % feature)
        if f in availableinterfaces:
            choseninterface = f

        if i is not None and defaultinterface != i:
            if f is not None:
                self.warn(_(b"invalid value for ui.interface: %s\n") % (i,))
            else:
                self.warn(
                    _(b"invalid value for ui.interface: %s (using %s)\n")
                    % (i, choseninterface)
                )
        if f is not None and choseninterface != f:
            self.warn(
                _(b"invalid value for ui.interface.%s: %s (using %s)\n")
                % (feature, f, choseninterface)
            )

        return choseninterface

        configuration variable or - if it is unset - when `sys.stdin' points
        to a terminal device.

        This function refers to input only; for output, see `ui.formatted()'.
        '''
        i = self.configbool(b"ui", b"interactive")
        if i is None:
            # some environments replace stdin without implementing isatty
            # usually those are non-interactive
            return self._isatty(self._fin)

        return i

    def termwidth(self):
        '''how wide is the terminal in columns?
        '''
        if b'COLUMNS' in encoding.environ:
            try:
                return int(encoding.environ[b'COLUMNS'])
            except ValueError:
                pass
        return scmutil.termsize(self)[0]

    def formatted(self):

        This function always returns false when in plain mode, see `ui.plain()'.
        '''
        if self.plain():
            return False

        i = self.configbool(b"ui", b"formatted")
        if i is None:
            # some environments replace stdout without implementing isatty
            # usually those are non-interactive
            return self._isatty(self._fout)

        return i

    def _readline(self, prompt=b' ', promptopts=None):
        # Replacing stdin/stdout temporarily is a hard problem on Python 3
        # because they have to be text streams with *no buffering*. Instead,
        # we use rawinput() only if call_readline() will be invoked by
        # PyOS_Readline(), so no I/O will be made at Python layer.
        usereadline = (

                readline.read_history_file
                # windows sometimes raises something other than ImportError
            except Exception:
                usereadline = False

        if self._colormode == b'win32' or not usereadline:
            if not promptopts:
                promptopts = {}
            self._writemsgnobuf(
                self._fmsgout, prompt, type=b'prompt', **promptopts
            )
            self.flush()
            prompt = b' '
        else:
            prompt = self.label(prompt, b'ui.prompt') + b' '

        # prompt ' ' must exist; otherwise readline may delete entire line
        # - http://bugs.python.org/issue12833
        with self.timeblockedsection(b'stdio'):
            if usereadline:
                line = encoding.strtolocal(pycompat.rawinput(prompt))
                # When stdin is in binary mode on Windows, it can cause
                # raw_input() to emit an extra trailing carriage return
                if pycompat.oslinesep == b'\r\n' and line.endswith(b'\r'):

                    raise EOFError
                line = line.rstrip(pycompat.oslinesep)

        return line

    def prompt(self, msg, default=b"y"):
        """Prompt user with msg, read response.
        If ui is not interactive, the default is returned.
        """
        return self._prompt(msg, default=default)

    def _prompt(self, msg, **opts):
        default = opts[r'default']
        if not self.interactive():
            self._writemsg(self._fmsgout, msg, b' ', type=b'prompt', **opts)
            self._writemsg(
                self._fmsgout, default or b'', b"\n", type=b'promptecho'
            )
            return default
        try:
            r = self._readline(prompt=msg, promptopts=opts)
            if not r:
                r = default
            if self.configbool(b'ui', b'promptecho'):
                self._writemsg(self._fmsgout, r, b"\n", type=b'promptecho')
            return r
        except EOFError:
            raise error.ResponseExpected()

    @staticmethod

        # prompt to start parsing. Sadly, we also can't rely on
        # choices containing spaces, ASCII, or basically anything
        # except an ampersand followed by a character.
        m = re.match(br'(?s)(.+?)\$\$([^\$]*&[^ \$].*)', prompt)
        msg = m.group(1)
        choices = [p.strip(b' ') for p in m.group(2).split(b'$$')]

        def choicetuple(s):
            ampidx = s.index(b'&')
            return s[ampidx + 1 : ampidx + 2].lower(), s.replace(b'&', b'', 1)

        return (msg, [choicetuple(s) for s in choices])

    def promptchoice(self, prompt, default=0):
        """Prompt user with a message, read response, and ensure it matches

        while True:
            r = self._prompt(msg, default=resps[default], choices=choices)
            if r.lower() in resps:
                return resps.index(r.lower())
            # TODO: shouldn't it be a warning?
            self._writemsg(self._fmsgout, _(b"unrecognized response\n"))

    def getpass(self, prompt=None, default=None):
        if not self.interactive():
            return default
        try:
            self._writemsg(
                self._fmsgerr,
                prompt or _(b'password: '),
                type=b'prompt',
                password=True,
            )
            # disable getpass() only if explicitly specified. it's still valid
            # to interact with tty even if fin is not a tty.
            with self.timeblockedsection(b'stdio'):
                if self.configbool(b'ui', b'nontty'):
                    l = self._fin.readline()
                    if not l:
                        raise EOFError
                    return l.rstrip(b'\n')
                else:
                    return getpass.getpass(r'')
        except EOFError:
            raise error.ResponseExpected()

        '''write status message to output (if ui.quiet is False)

        This adds an output label of "ui.status".
        '''
        if not self.quiet:
            self._writemsg(self._fmsgout, type=b'status', *msg, **opts)

    def warn(self, *msg, **opts):
        '''write warning message to output (stderr)

        This adds an output label of "ui.warning".
        '''
        self._writemsg(self._fmsgerr, type=b'warning', *msg, **opts)

    def error(self, *msg, **opts):
        '''write error message to output (stderr)

        This adds an output label of "ui.error".
        '''
        self._writemsg(self._fmsgerr, type=b'error', *msg, **opts)

    def note(self, *msg, **opts):
        '''write note to output (if ui.verbose is True)

        This adds an output label of "ui.note".
        '''
        if self.verbose:
            self._writemsg(self._fmsgout, type=b'note', *msg, **opts)

    def debug(self, *msg, **opts):
        '''write debug message to output (if ui.debugflag is True)

        This adds an output label of "ui.debug".
        '''
        if self.debugflag:
            self._writemsg(self._fmsgout, type=b'debug', *msg, **opts)
            self.log(b'debug', b'%s', b''.join(msg))

    def edit(
        self,
        text,

        repopath=None,
        action=None,
    ):
        if action is None:
            self.develwarn(
                b'action is None but will soon be a required '
                b'parameter to ui.edit()'
            )
        extra_defaults = {
            b'prefix': b'editor',
            b'suffix': b'.txt',
        }
        if extra is not None:
            if extra.get(b'suffix') is not None:
                self.develwarn(
                    b'extra.suffix is not None but will soon be '
                    b'ignored by ui.edit()'
                )
            extra_defaults.update(extra)
        extra = extra_defaults

        if action == b'diff':
            suffix = b'.diff'
        elif action:
            suffix = b'.%s.hg.txt' % action
        else:
            suffix = extra[b'suffix']

        rdir = None
        if self.configbool(b'experimental', b'editortmpinhg'):
            rdir = repopath
        (fd, name) = pycompat.mkstemp(
            prefix=b'hg-' + extra[b'prefix'] + b'-', suffix=suffix, dir=rdir
        )
        try:
            f = os.fdopen(fd, r'wb')
            f.write(util.tonativeeol(text))
            f.close()

            environ = {b'HGUSER': user}
            if b'transplant_source' in extra:
                environ.update(
                    {b'HGREVISION': hex(extra[b'transplant_source'])}
                )
            for label in (b'intermediate-source', b'source', b'rebase_source'):
                if label in extra:
                    environ.update({b'HGREVISION': extra[label]})
                    break
            if editform:
                environ.update({b'HGEDITFORM': editform})
            if pending:
                environ.update({b'HG_PENDING': pending})

            editor = self.geteditor()

            self.system(
                b"%s \"%s\"" % (editor, name),
                environ=environ,
                onerr=error.Abort,
                errprefix=_(b"edit failed"),
                blockedtag=b'editor',
            )

            f = open(name, r'rb')
            t = util.fromnativeeol(f.read())
            f.close()

        '''
        if blockedtag is None:
            # Long cmds tend to be because of an absolute path on cmd. Keep
            # the tail end instead
            cmdsuffix = cmd.translate(None, _keepalnum)[-85:]
            blockedtag = b'unknown_system_' + cmdsuffix
        out = self._fout
        if any(s[1] for s in self._bufferstates):
            out = self
        with self.timeblockedsection(blockedtag):
            rc = self._runsystem(cmd, environ=environ, cwd=cwd, out=out)
        if rc and onerr:
            errmsg = b'%s %s' % (
                os.path.basename(cmd.split(None, 1)[0]),
                procutil.explainexit(rc),
            )
            if errprefix:
                errmsg = b'%s: %s' % (errprefix, errmsg)
            raise onerr(errmsg)
        return rc

    def _runsystem(self, cmd, environ, cwd, out):
        """actually execute the given shell command (can be overridden by

                exctb = traceback.format_tb(exc[2])
                exconly = traceback.format_exception_only(cause[0], cause[1])

                # exclude frame where 'exc' was chained and rethrown from exctb
                self.write_err(
                    b'Traceback (most recent call last):\n',
                    b''.join(exctb[:-1]),
                    b''.join(causetb),
                    b''.join(exconly),
                )
            else:
                output = traceback.format_exception(exc[0], exc[1], exc[2])
                self.write_err(encoding.strtolocal(r''.join(output)))
        return self.tracebackflag or force

    def geteditor(self):
        '''return editor to use'''
        if pycompat.sysplatform == b'plan9':
            # vi is the MIPS instruction simulator on Plan 9. We
            # instead default to E to plumb commit messages to
            # avoid confusion.
            editor = b'E'
        else:
            editor = b'vi'
        return encoding.environ.get(b"HGEDITOR") or self.config(
            b"ui", b"editor", editor
        )

    @util.propertycache
    def _progbar(self):
        """setup the progbar singleton to the ui object"""
        if (
            self.quiet
            or self.debugflag
            or self.configbool(b'progress', b'disable')
            or not progress.shouldprint(self)
        ):
            return None
        return getprogbar(self)

        if not haveprogbar():  # nothing loaded yet
            return
        if self._progbar is not None and self._progbar.printed:
            self._progbar.clear()

    def progress(self, topic, pos, item=b"", unit=b"", total=None):
        '''show a progress message

        By default a textual progress bar will be displayed if an operation
        takes too long. 'topic' is the current operation, 'item' is a
        non-numeric marker of the current position (i.e. the currently

        Multiple nested topics may be active at a time.

        All topics should be marked closed by setting pos to None at
        termination.
        '''
        self.deprecwarn(
            b"use ui.makeprogress() instead of ui.progress()", b"5.1"
        )
        progress = self.makeprogress(topic, unit, total)
        if pos is not None:
            progress.update(pos, item=item)
        else:
            progress.complete()

    def makeprogress(self, topic, unit=b"", total=None):
        """Create a progress helper for the specified topic"""
        if getattr(self._fmsgerr, 'structured', False):
            # channel for machine-readable output with metadata, just send
            # raw information
            # TODO: consider porting some useful information (e.g. estimated

        """issue a developer warning message

        Use 'stacklevel' to report the offender some layers further up in the
        stack.
        """
        if not self.configbool(b'devel', b'all-warnings'):
            if config is None or not self.configbool(b'devel', config):
                return
        msg = b'devel-warn: ' + msg
        stacklevel += 1  # get in develwarn
        if self.tracebackflag:
            util.debugstacktrace(msg, stacklevel, self._ferr, self._fout)
            self.log(
                b'develwarn',
                b'%s at:\n%s'
                % (msg, b''.join(util.getstackframes(stacklevel))),
            )
        else:
            curframe = inspect.currentframe()
            calframe = inspect.getouterframes(curframe, 2)
            fname, lineno, fmsg = calframe[stacklevel][1:4]
            fname, fmsg = pycompat.sysbytes(fname), pycompat.sysbytes(fmsg)
            self.write_err(b'%s at: %s:%d (%s)\n' % (msg, fname, lineno, fmsg))
            self.log(
                b'develwarn', b'%s at: %s:%d (%s)\n', msg, fname, lineno, fmsg
            )
            curframe = calframe = None  # avoid cycles

    def deprecwarn(self, msg, version, stacklevel=2):
        """issue a deprecation warning

        - msg: message explaining what is deprecated and how to upgrade,
        - version: last version where the API will be supported,
        """
        if not (
            self.configbool(b'devel', b'all-warnings')
            or self.configbool(b'devel', b'deprec-warn')
        ):
            return
        msg += (
            b"\n(compatibility will be dropped after Mercurial-%s,"
            b" update your code.)"
        ) % version
        self.develwarn(msg, stacklevel=stacklevel, config=b'deprec-warn')

    def exportableenviron(self):
        """The environment variables that are safe to export, e.g. through
        hgweb.
        """
        return self._exportableenviron

    @contextlib.contextmanager
    def configoverride(self, overrides, source=b""):
        """Context manager for temporary config overrides
        `overrides` must be a dict of the following structure:
        {(section, name) : value}"""
        backups = {}
        try:

        finally:
            for __, backup in backups.items():
                self.restoreconfig(backup)
            # just restoring ui.quiet config to the previous value is not enough
            # as it does not update ui.quiet class member
            if (b'ui', b'quiet') in overrides:
                self.fixconfig(section=b'ui')


class paths(dict):
    """Represents a collection of paths and their configs.

    """

    def __init__(self, ui):
        dict.__init__(self)

        for name, loc in ui.configitems(b'paths', ignoresub=True):
            # No location is the same as not existing.
            if not loc:
                continue
            loc, sub = ui.configsuboptions(b'paths', name)
            self[name] = path(ui, name, rawloc=loc, suboptions=sub)

    def getpath(self, name, default=None):
        """Return a ``path`` from a string, falling back to default.

            # Try to resolve as a local path or URI.
            try:
                # We don't pass sub-options in, so no need to pass ui instance.
                return path(None, None, rawloc=name)
            except ValueError:
                raise error.RepoError(_(b'repository %s does not exist') % name)


_pathsuboptions = {}

        return func

    return register


@pathsuboption(b'pushurl', b'pushloc')
def pushurlpathoption(ui, path, value):
    u = util.url(value)
    # Actually require a URL.
    if not u.scheme:
        ui.warn(_(b'(paths.%s:pushurl not a URL; ignoring)\n') % path.name)
        return None

    # Don't support the #foo syntax in the push URL to declare branch to
    # push.
    if u.fragment:
        ui.warn(
            _(
                b'("#fragment" in paths.%s:pushurl not supported; '
                b'ignoring)\n'
            )
            % path.name
        )
        u.fragment = None

    return bytes(u)


@pathsuboption(b'pushrev', b'pushrev')
def pushrevpathoption(ui, path, value):
    return value


class path(object):

        If ``name`` is not defined, we require that the location be a) a local
        filesystem path with a .hg directory or b) a URL. If not,
        ``ValueError`` is raised.
        """
        if not rawloc:
            raise ValueError(b'rawloc must be defined')

        # Locations may define branches via syntax <base>#<branch>.
        u = util.url(rawloc)
        branch = None
        if u.fragment:

        self.url = u
        self.branch = branch

        self.name = name
        self.rawloc = rawloc
        self.loc = b'%s' % u

        # When given a raw location but not a symbolic name, validate the
        # location is valid.
        if not name and not u.scheme and not self._isvalidlocalpath(self.loc):
            raise ValueError(
                b'location is not a URL or path to a local '
                b'repo: %s' % rawloc
            )

        suboptions = suboptions or {}

        # Now process the sub-options. If a sub-option is registered, its

        """Returns True if the given path is a potentially valid repository.
        This is its own function so that extensions can change the definition of
        'valid' in this case (like when pulling from a git repo into a hg
        one)."""
        try:
            return os.path.isdir(os.path.join(path, b'.hg'))
        # Python 2 may return TypeError. Python 3, ValueError.
        except (TypeError, ValueError):
            return False

    @property

    The specified message type is translated to 'ui.<type>' label if the dest
    isn't a structured channel, so that the message will be colorized.
    """
    # TODO: maybe change 'type' to a mandatory option
    if r'type' in opts and not getattr(dest, 'structured', False):
        opts[r'label'] = opts.get(r'label', b'') + b' ui.%s' % opts.pop(r'type')
    write(dest, *args, **opts)