re2: fix reporting of availability in `hg debuginstall`

We add and use an official API to check is re2 is available. This prevent the
bug previously in place were debuginstall was considering confusing `None`
(i.e. non-initialized) and `False` (i.e. unavailable).

mercurial/debugcommands.py

@@ -1,4783 +1,4783 b''
 # debugcommands.py - command processing for debug* commands
 #
 # Copyright 2005-2016 Olivia Mackall <[e-mail]>
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 
 import binascii
 import codecs
 import collections
 import contextlib
 import difflib
 import errno
 import glob
 import operator
 import os
 import platform
 import random
 import re
 import socket
 import ssl
 import stat
 import subprocess
 import sys
 import time
 
 from .i18n import _
 from .node import (
     bin,
     hex,
     nullrev,
     short,
 )
 from .pycompat import (
     getattr,
     open,
 )
 from . import (
     bundle2,
     bundlerepo,
     changegroup,
     cmdutil,
     color,
     context,
     copies,
     dagparser,
     dirstateutils,
     encoding,
     error,
     exchange,
     extensions,
     filemerge,
     filesetlang,
     formatter,
     hg,
     httppeer,
     localrepo,
     lock as lockmod,
     logcmdutil,
     mergestate as mergestatemod,
     metadata,
     obsolete,
     obsutil,
     pathutil,
     phases,
     policy,
     pvec,
     pycompat,
     registrar,
     repair,
     repoview,
     requirements,
     revlog,
     revset,
     revsetlang,
     scmutil,
     setdiscovery,
     simplemerge,
     sshpeer,
     sslutil,
     streamclone,
     strip,
     tags as tagsmod,
     templater,
     treediscovery,
     upgrade,
     url as urlmod,
     util,
     verify,
     vfs as vfsmod,
     wireprotoframing,
     wireprotoserver,
 )
 from .interfaces import repository
 from .utils import (
     cborutil,
     compression,
     dateutil,
     procutil,
     stringutil,
     urlutil,
 )
 
 from .revlogutils import (
     constants as revlog_constants,
     debug as revlog_debug,
     deltas as deltautil,
     nodemap,
     rewrite,
     sidedata,
 )
 
 release = lockmod.release
 
 table = {}
 table.update(strip.command._table)
 command = registrar.command(table)
 
 
 @command(b'debugancestor', [], _(b'[INDEX] REV1 REV2'), optionalrepo=True)
 def debugancestor(ui, repo, *args):
     """find the ancestor revision of two revisions in a given index"""
     if len(args) == 3:
         index, rev1, rev2 = args
         r = revlog.revlog(vfsmod.vfs(encoding.getcwd(), audit=False), index)
         lookup = r.lookup
     elif len(args) == 2:
         if not repo:
             raise error.Abort(
                 _(b'there is no Mercurial repository here (.hg not found)')
             )
         rev1, rev2 = args
         r = repo.changelog
         lookup = repo.lookup
     else:
         raise error.Abort(_(b'either two or three arguments required'))
     a = r.ancestor(lookup(rev1), lookup(rev2))
     ui.write(b'%d:%s\n' % (r.rev(a), hex(a)))
 
 
 @command(b'debugantivirusrunning', [])
 def debugantivirusrunning(ui, repo):
     """attempt to trigger an antivirus scanner to see if one is active"""
     with repo.cachevfs.open('eicar-test-file.com', b'wb') as f:
         f.write(
             util.b85decode(
                 # This is a base85-armored version of the EICAR test file. See
                 # https://en.wikipedia.org/wiki/EICAR_test_file for details.
                 b'ST#=}P$fV?P+K%yP+C|uG$>GBDK|qyDK~v2MM*<JQY}+dK~6+LQba95P'
                 b'E<)&Nm5l)EmTEQR4qnHOhq9iNGnJx'
             )
         )
     # Give an AV engine time to scan the file.
     time.sleep(2)
     util.unlink(repo.cachevfs.join('eicar-test-file.com'))
 
 
 @command(b'debugapplystreamclonebundle', [], b'FILE')
 def debugapplystreamclonebundle(ui, repo, fname):
     """apply a stream clone bundle file"""
     f = hg.openpath(ui, fname)
     gen = exchange.readbundle(ui, f, fname)
     gen.apply(repo)
 
 
 @command(
     b'debugbuilddag',
     [
         (
             b'm',
             b'mergeable-file',
             None,
             _(b'add single file mergeable changes'),
         ),
         (
             b'o',
             b'overwritten-file',
             None,
             _(b'add single file all revs overwrite'),
         ),
         (b'n', b'new-file', None, _(b'add new file at each rev')),
         (
             b'',
             b'from-existing',
             None,
             _(b'continue from a non-empty repository'),
         ),
     ],
     _(b'[OPTION]... [TEXT]'),
 )
 def debugbuilddag(
     ui,
     repo,
     text=None,
     mergeable_file=False,
     overwritten_file=False,
     new_file=False,
     from_existing=False,
 ):
     """builds a repo with a given DAG from scratch in the current empty repo
 
     The description of the DAG is read from stdin if not given on the
     command line.
 
     Elements:
 
      - "+n" is a linear run of n nodes based on the current default parent
      - "." is a single node based on the current default parent
      - "$" resets the default parent to null (implied at the start);
            otherwise the default parent is always the last node created
      - "<p" sets the default parent to the backref p
      - "*p" is a fork at parent p, which is a backref
      - "*p1/p2" is a merge of parents p1 and p2, which are backrefs
      - "/p2" is a merge of the preceding node and p2
      - ":tag" defines a local tag for the preceding node
      - "@branch" sets the named branch for subsequent nodes
      - "#...\\n" is a comment up to the end of the line
 
     Whitespace between the above elements is ignored.
 
     A backref is either
 
      - a number n, which references the node curr-n, where curr is the current
        node, or
      - the name of a local tag you placed earlier using ":tag", or
      - empty to denote the default parent.
 
     All string valued-elements are either strictly alphanumeric, or must
     be enclosed in double quotes ("..."), with "\\" as escape character.
     """
 
     if text is None:
         ui.status(_(b"reading DAG from stdin\n"))
         text = ui.fin.read()
 
     cl = repo.changelog
     if len(cl) > 0 and not from_existing:
         raise error.Abort(_(b'repository is not empty'))
 
     # determine number of revs in DAG
     total = 0
     for type, data in dagparser.parsedag(text):
         if type == b'n':
             total += 1
 
     if mergeable_file:
         linesperrev = 2
         # make a file with k lines per rev
         initialmergedlines = [b'%d' % i for i in range(0, total * linesperrev)]
         initialmergedlines.append(b"")
 
     tags = []
     progress = ui.makeprogress(
         _(b'building'), unit=_(b'revisions'), total=total
     )
     with progress, repo.wlock(), repo.lock(), repo.transaction(b"builddag"):
         at = -1
         atbranch = b'default'
         nodeids = []
         id = 0
         progress.update(id)
         for type, data in dagparser.parsedag(text):
             if type == b'n':
                 ui.note((b'node %s\n' % pycompat.bytestr(data)))
                 id, ps = data
 
                 files = []
                 filecontent = {}
 
                 p2 = None
                 if mergeable_file:
                     fn = b"mf"
                     p1 = repo[ps[0]]
                     if len(ps) > 1:
                         p2 = repo[ps[1]]
                         pa = p1.ancestor(p2)
                         base, local, other = [
                             x[fn].data() for x in (pa, p1, p2)
                         ]
                         m3 = simplemerge.Merge3Text(base, local, other)
                         ml = [
                             l.strip()
                             for l in simplemerge.render_minimized(m3)[0]
                         ]
                         ml.append(b"")
                     elif at > 0:
                         ml = p1[fn].data().split(b"\n")
                     else:
                         ml = initialmergedlines
                     ml[id * linesperrev] += b" r%i" % id
                     mergedtext = b"\n".join(ml)
                     files.append(fn)
                     filecontent[fn] = mergedtext
 
                 if overwritten_file:
                     fn = b"of"
                     files.append(fn)
                     filecontent[fn] = b"r%i\n" % id
 
                 if new_file:
                     fn = b"nf%i" % id
                     files.append(fn)
                     filecontent[fn] = b"r%i\n" % id
                     if len(ps) > 1:
                         if not p2:
                             p2 = repo[ps[1]]
                         for fn in p2:
                             if fn.startswith(b"nf"):
                                 files.append(fn)
                                 filecontent[fn] = p2[fn].data()
 
                 def fctxfn(repo, cx, path):
                     if path in filecontent:
                         return context.memfilectx(
                             repo, cx, path, filecontent[path]
                         )
                     return None
 
                 if len(ps) == 0 or ps[0] < 0:
                     pars = [None, None]
                 elif len(ps) == 1:
                     pars = [nodeids[ps[0]], None]
                 else:
                     pars = [nodeids[p] for p in ps]
                 cx = context.memctx(
                     repo,
                     pars,
                     b"r%i" % id,
                     files,
                     fctxfn,
                     date=(id, 0),
                     user=b"debugbuilddag",
                     extra={b'branch': atbranch},
                 )
                 nodeid = repo.commitctx(cx)
                 nodeids.append(nodeid)
                 at = id
             elif type == b'l':
                 id, name = data
                 ui.note((b'tag %s\n' % name))
                 tags.append(b"%s %s\n" % (hex(repo.changelog.node(id)), name))
             elif type == b'a':
                 ui.note((b'branch %s\n' % data))
                 atbranch = data
             progress.update(id)
 
         if tags:
             repo.vfs.write(b"localtags", b"".join(tags))
 
 
 def _debugchangegroup(ui, gen, all=None, indent=0, **opts):
     indent_string = b' ' * indent
     if all:
         ui.writenoi18n(
             b"%sformat: id, p1, p2, cset, delta base, len(delta)\n"
             % indent_string
         )
 
         def showchunks(named):
             ui.write(b"\n%s%s\n" % (indent_string, named))
             for deltadata in gen.deltaiter():
                 node, p1, p2, cs, deltabase, delta, flags, sidedata = deltadata
                 ui.write(
                     b"%s%s %s %s %s %s %d\n"
                     % (
                         indent_string,
                         hex(node),
                         hex(p1),
                         hex(p2),
                         hex(cs),
                         hex(deltabase),
                         len(delta),
                     )
                 )
 
         gen.changelogheader()
         showchunks(b"changelog")
         gen.manifestheader()
         showchunks(b"manifest")
         for chunkdata in iter(gen.filelogheader, {}):
             fname = chunkdata[b'filename']
             showchunks(fname)
     else:
         if isinstance(gen, bundle2.unbundle20):
             raise error.Abort(_(b'use debugbundle2 for this file'))
         gen.changelogheader()
         for deltadata in gen.deltaiter():
             node, p1, p2, cs, deltabase, delta, flags, sidedata = deltadata
             ui.write(b"%s%s\n" % (indent_string, hex(node)))
 
 
 def _debugobsmarkers(ui, part, indent=0, **opts):
     """display version and markers contained in 'data'"""
     opts = pycompat.byteskwargs(opts)
     data = part.read()
     indent_string = b' ' * indent
     try:
         version, markers = obsolete._readmarkers(data)
     except error.UnknownVersion as exc:
         msg = b"%sunsupported version: %s (%d bytes)\n"
         msg %= indent_string, exc.version, len(data)
         ui.write(msg)
     else:
         msg = b"%sversion: %d (%d bytes)\n"
         msg %= indent_string, version, len(data)
         ui.write(msg)
         fm = ui.formatter(b'debugobsolete', opts)
         for rawmarker in sorted(markers):
             m = obsutil.marker(None, rawmarker)
             fm.startitem()
             fm.plain(indent_string)
             cmdutil.showmarker(fm, m)
         fm.end()
 
 
 def _debugphaseheads(ui, data, indent=0):
     """display version and markers contained in 'data'"""
     indent_string = b' ' * indent
     headsbyphase = phases.binarydecode(data)
     for phase in phases.allphases:
         for head in headsbyphase[phase]:
             ui.write(indent_string)
             ui.write(b'%s %s\n' % (hex(head), phases.phasenames[phase]))
 
 
 def _quasirepr(thing):
     if isinstance(thing, (dict, util.sortdict, collections.OrderedDict)):
         return b'{%s}' % (
             b', '.join(b'%s: %s' % (k, thing[k]) for k in sorted(thing))
         )
     return pycompat.bytestr(repr(thing))
 
 
 def _debugbundle2(ui, gen, all=None, **opts):
     """lists the contents of a bundle2"""
     if not isinstance(gen, bundle2.unbundle20):
         raise error.Abort(_(b'not a bundle2 file'))
     ui.write((b'Stream params: %s\n' % _quasirepr(gen.params)))
     parttypes = opts.get('part_type', [])
     for part in gen.iterparts():
         if parttypes and part.type not in parttypes:
             continue
         msg = b'%s -- %s (mandatory: %r)\n'
         ui.write((msg % (part.type, _quasirepr(part.params), part.mandatory)))
         if part.type == b'changegroup':
             version = part.params.get(b'version', b'01')
             cg = changegroup.getunbundler(version, part, b'UN')
             if not ui.quiet:
                 _debugchangegroup(ui, cg, all=all, indent=4, **opts)
         if part.type == b'obsmarkers':
             if not ui.quiet:
                 _debugobsmarkers(ui, part, indent=4, **opts)
         if part.type == b'phase-heads':
             if not ui.quiet:
                 _debugphaseheads(ui, part, indent=4)
 
 
 @command(
     b'debugbundle',
     [
         (b'a', b'all', None, _(b'show all details')),
         (b'', b'part-type', [], _(b'show only the named part type')),
         (b'', b'spec', None, _(b'print the bundlespec of the bundle')),
     ],
     _(b'FILE'),
     norepo=True,
 )
 def debugbundle(ui, bundlepath, all=None, spec=None, **opts):
     """lists the contents of a bundle"""
     with hg.openpath(ui, bundlepath) as f:
         if spec:
             spec = exchange.getbundlespec(ui, f)
             ui.write(b'%s\n' % spec)
             return
 
         gen = exchange.readbundle(ui, f, bundlepath)
         if isinstance(gen, bundle2.unbundle20):
             return _debugbundle2(ui, gen, all=all, **opts)
         _debugchangegroup(ui, gen, all=all, **opts)
 
 
 @command(b'debugcapabilities', [], _(b'PATH'), norepo=True)
 def debugcapabilities(ui, path, **opts):
     """lists the capabilities of a remote peer"""
     opts = pycompat.byteskwargs(opts)
     peer = hg.peer(ui, opts, path)
     try:
         caps = peer.capabilities()
         ui.writenoi18n(b'Main capabilities:\n')
         for c in sorted(caps):
             ui.write(b'  %s\n' % c)
         b2caps = bundle2.bundle2caps(peer)
         if b2caps:
             ui.writenoi18n(b'Bundle2 capabilities:\n')
             for key, values in sorted(b2caps.items()):
                 ui.write(b'  %s\n' % key)
                 for v in values:
                     ui.write(b'    %s\n' % v)
     finally:
         peer.close()
 
 
 @command(
     b'debugchangedfiles',
     [
         (
             b'',
             b'compute',
             False,
             b"compute information instead of reading it from storage",
         ),
     ],
     b'REV',
 )
 def debugchangedfiles(ui, repo, rev, **opts):
     """list the stored files changes for a revision"""
     ctx = logcmdutil.revsingle(repo, rev, None)
     files = None
 
     if opts['compute']:
         files = metadata.compute_all_files_changes(ctx)
     else:
         sd = repo.changelog.sidedata(ctx.rev())
         files_block = sd.get(sidedata.SD_FILES)
         if files_block is not None:
             files = metadata.decode_files_sidedata(sd)
     if files is not None:
         for f in sorted(files.touched):
             if f in files.added:
                 action = b"added"
             elif f in files.removed:
                 action = b"removed"
             elif f in files.merged:
                 action = b"merged"
             elif f in files.salvaged:
                 action = b"salvaged"
             else:
                 action = b"touched"
 
             copy_parent = b""
             copy_source = b""
             if f in files.copied_from_p1:
                 copy_parent = b"p1"
                 copy_source = files.copied_from_p1[f]
             elif f in files.copied_from_p2:
                 copy_parent = b"p2"
                 copy_source = files.copied_from_p2[f]
 
             data = (action, copy_parent, f, copy_source)
             template = b"%-8s %2s: %s, %s;\n"
             ui.write(template % data)
 
 
 @command(b'debugcheckstate', [], b'')
 def debugcheckstate(ui, repo):
     """validate the correctness of the current dirstate"""
     errors = verify.verifier(repo)._verify_dirstate()
     if errors:
         errstr = _(b"dirstate inconsistent with current parent's manifest")
         raise error.Abort(errstr)
 
 
 @command(
     b'debugcolor',
     [(b'', b'style', None, _(b'show all configured styles'))],
     b'hg debugcolor',
 )
 def debugcolor(ui, repo, **opts):
     """show available color, effects or style"""
     ui.writenoi18n(b'color mode: %s\n' % stringutil.pprint(ui._colormode))
     if opts.get('style'):
         return _debugdisplaystyle(ui)
     else:
         return _debugdisplaycolor(ui)
 
 
 def _debugdisplaycolor(ui):
     ui = ui.copy()
     ui._styles.clear()
     for effect in color._activeeffects(ui).keys():
         ui._styles[effect] = effect
     if ui._terminfoparams:
         for k, v in ui.configitems(b'color'):
             if k.startswith(b'color.'):
                 ui._styles[k] = k[6:]
             elif k.startswith(b'terminfo.'):
                 ui._styles[k] = k[9:]
     ui.write(_(b'available colors:\n'))
     # sort label with a '_' after the other to group '_background' entry.
     items = sorted(ui._styles.items(), key=lambda i: (b'_' in i[0], i[0], i[1]))
     for colorname, label in items:
         ui.write(b'%s\n' % colorname, label=label)
 
 
 def _debugdisplaystyle(ui):
     ui.write(_(b'available style:\n'))
     if not ui._styles:
         return
     width = max(len(s) for s in ui._styles)
     for label, effects in sorted(ui._styles.items()):
         ui.write(b'%s' % label, label=label)
         if effects:
             # 50
             ui.write(b': ')
             ui.write(b' ' * (max(0, width - len(label))))
             ui.write(b', '.join(ui.label(e, e) for e in effects.split()))
         ui.write(b'\n')
 
 
 @command(b'debugcreatestreamclonebundle', [], b'FILE')
 def debugcreatestreamclonebundle(ui, repo, fname):
     """create a stream clone bundle file
 
     Stream bundles are special bundles that are essentially archives of
     revlog files. They are commonly used for cloning very quickly.
     """
     # TODO we may want to turn this into an abort when this functionality
     # is moved into `hg bundle`.
     if phases.hassecret(repo):
         ui.warn(
             _(
                 b'(warning: stream clone bundle will contain secret '
                 b'revisions)\n'
             )
         )
 
     requirements, gen = streamclone.generatebundlev1(repo)
     changegroup.writechunks(ui, gen, fname)
 
     ui.write(_(b'bundle requirements: %s\n') % b', '.join(sorted(requirements)))
 
 
 @command(
     b'debugdag',
     [
         (b't', b'tags', None, _(b'use tags as labels')),
         (b'b', b'branches', None, _(b'annotate with branch names')),
         (b'', b'dots', None, _(b'use dots for runs')),
         (b's', b'spaces', None, _(b'separate elements by spaces')),
     ],
     _(b'[OPTION]... [FILE [REV]...]'),
     optionalrepo=True,
 )
 def debugdag(ui, repo, file_=None, *revs, **opts):
     """format the changelog or an index DAG as a concise textual description
 
     If you pass a revlog index, the revlog's DAG is emitted. If you list
     revision numbers, they get labeled in the output as rN.
 
     Otherwise, the changelog DAG of the current repo is emitted.
     """
     spaces = opts.get('spaces')
     dots = opts.get('dots')
     if file_:
         rlog = revlog.revlog(vfsmod.vfs(encoding.getcwd(), audit=False), file_)
         revs = {int(r) for r in revs}
 
         def events():
             for r in rlog:
                 yield b'n', (r, list(p for p in rlog.parentrevs(r) if p != -1))
                 if r in revs:
                     yield b'l', (r, b"r%i" % r)
 
     elif repo:
         cl = repo.changelog
         tags = opts.get('tags')
         branches = opts.get('branches')
         if tags:
             labels = {}
             for l, n in repo.tags().items():
                 labels.setdefault(cl.rev(n), []).append(l)
 
         def events():
             b = b"default"
             for r in cl:
                 if branches:
                     newb = cl.read(cl.node(r))[5][b'branch']
                     if newb != b:
                         yield b'a', newb
                         b = newb
                 yield b'n', (r, list(p for p in cl.parentrevs(r) if p != -1))
                 if tags:
                     ls = labels.get(r)
                     if ls:
                         for l in ls:
                             yield b'l', (r, l)
 
     else:
         raise error.Abort(_(b'need repo for changelog dag'))
 
     for line in dagparser.dagtextlines(
         events(),
         addspaces=spaces,
         wraplabels=True,
         wrapannotations=True,
         wrapnonlinear=dots,
         usedots=dots,
         maxlinewidth=70,
     ):
         ui.write(line)
         ui.write(b"\n")
 
 
 @command(b'debugdata', cmdutil.debugrevlogopts, _(b'-c|-m|FILE REV'))
 def debugdata(ui, repo, file_, rev=None, **opts):
     """dump the contents of a data file revision"""
     opts = pycompat.byteskwargs(opts)
     if opts.get(b'changelog') or opts.get(b'manifest') or opts.get(b'dir'):
         if rev is not None:
             raise error.CommandError(b'debugdata', _(b'invalid arguments'))
         file_, rev = None, file_
     elif rev is None:
         raise error.CommandError(b'debugdata', _(b'invalid arguments'))
     r = cmdutil.openstorage(repo, b'debugdata', file_, opts)
     try:
         ui.write(r.rawdata(r.lookup(rev)))
     except KeyError:
         raise error.Abort(_(b'invalid revision identifier %s') % rev)
 
 
 @command(
     b'debugdate',
     [(b'e', b'extended', None, _(b'try extended date formats'))],
     _(b'[-e] DATE [RANGE]'),
     norepo=True,
     optionalrepo=True,
 )
 def debugdate(ui, date, range=None, **opts):
     """parse and display a date"""
     if opts["extended"]:
         d = dateutil.parsedate(date, dateutil.extendeddateformats)
     else:
         d = dateutil.parsedate(date)
     ui.writenoi18n(b"internal: %d %d\n" % d)
     ui.writenoi18n(b"standard: %s\n" % dateutil.datestr(d))
     if range:
         m = dateutil.matchdate(range)
         ui.writenoi18n(b"match: %s\n" % m(d[0]))
 
 
 @command(
     b'debugdeltachain',
     cmdutil.debugrevlogopts + cmdutil.formatteropts,
     _(b'-c|-m|FILE'),
     optionalrepo=True,
 )
 def debugdeltachain(ui, repo, file_=None, **opts):
     """dump information about delta chains in a revlog
 
     Output can be templatized. Available template keywords are:
 
     :``rev``:       revision number
     :``p1``:        parent 1 revision number (for reference)
     :``p2``:        parent 2 revision number (for reference)
     :``chainid``:   delta chain identifier (numbered by unique base)
     :``chainlen``:  delta chain length to this revision
     :``prevrev``:   previous revision in delta chain
     :``deltatype``: role of delta / how it was computed
                     - base:  a full snapshot
                     - snap:  an intermediate snapshot
                     - p1:    a delta against the first parent
                     - p2:    a delta against the second parent
                     - skip1: a delta against the same base as p1
                               (when p1 has empty delta
                     - skip2: a delta against the same base as p2
                               (when p2 has empty delta
                     - prev:  a delta against the previous revision
                     - other: a delta against an arbitrary revision
     :``compsize``:  compressed size of revision
     :``uncompsize``: uncompressed size of revision
     :``chainsize``: total size of compressed revisions in chain
     :``chainratio``: total chain size divided by uncompressed revision size
                     (new delta chains typically start at ratio 2.00)
     :``lindist``:   linear distance from base revision in delta chain to end
                     of this revision
     :``extradist``: total size of revisions not part of this delta chain from
                     base of delta chain to end of this revision; a measurement
                     of how much extra data we need to read/seek across to read
                     the delta chain for this revision
     :``extraratio``: extradist divided by chainsize; another representation of
                     how much unrelated data is needed to load this delta chain
 
     If the repository is configured to use the sparse read, additional keywords
     are available:
 
     :``readsize``:     total size of data read from the disk for a revision
                        (sum of the sizes of all the blocks)
     :``largestblock``: size of the largest block of data read from the disk
     :``readdensity``:  density of useful bytes in the data read from the disk
     :``srchunks``:  in how many data hunks the whole revision would be read
 
     The sparse read can be enabled with experimental.sparse-read = True
     """
     opts = pycompat.byteskwargs(opts)
     r = cmdutil.openrevlog(repo, b'debugdeltachain', file_, opts)
     index = r.index
     start = r.start
     length = r.length
     generaldelta = r._generaldelta
     withsparseread = getattr(r, '_withsparseread', False)
 
     # security to avoid crash on corrupted revlogs
     total_revs = len(index)
 
     chain_size_cache = {}
 
     def revinfo(rev):
         e = index[rev]
         compsize = e[revlog_constants.ENTRY_DATA_COMPRESSED_LENGTH]
         uncompsize = e[revlog_constants.ENTRY_DATA_UNCOMPRESSED_LENGTH]
 
         base = e[revlog_constants.ENTRY_DELTA_BASE]
         p1 = e[revlog_constants.ENTRY_PARENT_1]
         p2 = e[revlog_constants.ENTRY_PARENT_2]
 
         # If the parents of a revision has an empty delta, we never try to delta
         # against that parent, but directly against the delta base of that
         # parent (recursively). It avoids adding a useless entry in the chain.
         #
         # However we need to detect that as a special case for delta-type, that
         # is not simply "other".
         p1_base = p1
         if p1 != nullrev and p1 < total_revs:
             e1 = index[p1]
             while e1[revlog_constants.ENTRY_DATA_COMPRESSED_LENGTH] == 0:
                 new_base = e1[revlog_constants.ENTRY_DELTA_BASE]
                 if (
                     new_base == p1_base
                     or new_base == nullrev
                     or new_base >= total_revs
                 ):
                     break
                 p1_base = new_base
                 e1 = index[p1_base]
         p2_base = p2
         if p2 != nullrev and p2 < total_revs:
             e2 = index[p2]
             while e2[revlog_constants.ENTRY_DATA_COMPRESSED_LENGTH] == 0:
                 new_base = e2[revlog_constants.ENTRY_DELTA_BASE]
                 if (
                     new_base == p2_base
                     or new_base == nullrev
                     or new_base >= total_revs
                 ):
                     break
                 p2_base = new_base
                 e2 = index[p2_base]
 
         if generaldelta:
             if base == p1:
                 deltatype = b'p1'
             elif base == p2:
                 deltatype = b'p2'
             elif base == rev:
                 deltatype = b'base'
             elif base == p1_base:
                 deltatype = b'skip1'
             elif base == p2_base:
                 deltatype = b'skip2'
             elif r.issnapshot(rev):
                 deltatype = b'snap'
             elif base == rev - 1:
                 deltatype = b'prev'
             else:
                 deltatype = b'other'
         else:
             if base == rev:
                 deltatype = b'base'
             else:
                 deltatype = b'prev'
 
         chain = r._deltachain(rev)[0]
         chain_size = 0
         for iter_rev in reversed(chain):
             cached = chain_size_cache.get(iter_rev)
             if cached is not None:
                 chain_size += cached
                 break
             e = index[iter_rev]
             chain_size += e[revlog_constants.ENTRY_DATA_COMPRESSED_LENGTH]
         chain_size_cache[rev] = chain_size
 
         return p1, p2, compsize, uncompsize, deltatype, chain, chain_size
 
     fm = ui.formatter(b'debugdeltachain', opts)
 
     fm.plain(
         b'    rev      p1      p2  chain# chainlen     prev   delta       '
         b'size    rawsize  chainsize     ratio   lindist extradist '
         b'extraratio'
     )
     if withsparseread:
         fm.plain(b'   readsize largestblk rddensity srchunks')
     fm.plain(b'\n')
 
     chainbases = {}
     for rev in r:
         p1, p2, comp, uncomp, deltatype, chain, chainsize = revinfo(rev)
         chainbase = chain[0]
         chainid = chainbases.setdefault(chainbase, len(chainbases) + 1)
         basestart = start(chainbase)
         revstart = start(rev)
         lineardist = revstart + comp - basestart
         extradist = lineardist - chainsize
         try:
             prevrev = chain[-2]
         except IndexError:
             prevrev = -1
 
         if uncomp != 0:
             chainratio = float(chainsize) / float(uncomp)
         else:
             chainratio = chainsize
 
         if chainsize != 0:
             extraratio = float(extradist) / float(chainsize)
         else:
             extraratio = extradist
 
         fm.startitem()
         fm.write(
             b'rev p1 p2 chainid chainlen prevrev deltatype compsize '
             b'uncompsize chainsize chainratio lindist extradist '
             b'extraratio',
             b'%7d %7d %7d %7d %8d %8d %7s %10d %10d %10d %9.5f %9d %9d %10.5f',
             rev,
             p1,
             p2,
             chainid,
             len(chain),
             prevrev,
             deltatype,
             comp,
             uncomp,
             chainsize,
             chainratio,
             lineardist,
             extradist,
             extraratio,
             rev=rev,
             chainid=chainid,
             chainlen=len(chain),
             prevrev=prevrev,
             deltatype=deltatype,
             compsize=comp,
             uncompsize=uncomp,
             chainsize=chainsize,
             chainratio=chainratio,
             lindist=lineardist,
             extradist=extradist,
             extraratio=extraratio,
         )
         if withsparseread:
             readsize = 0
             largestblock = 0
             srchunks = 0
 
             for revschunk in deltautil.slicechunk(r, chain):
                 srchunks += 1
                 blkend = start(revschunk[-1]) + length(revschunk[-1])
                 blksize = blkend - start(revschunk[0])
 
                 readsize += blksize
                 if largestblock < blksize:
                     largestblock = blksize
 
             if readsize:
                 readdensity = float(chainsize) / float(readsize)
             else:
                 readdensity = 1
 
             fm.write(
                 b'readsize largestblock readdensity srchunks',
                 b' %10d %10d %9.5f %8d',
                 readsize,
                 largestblock,
                 readdensity,
                 srchunks,
                 readsize=readsize,
                 largestblock=largestblock,
                 readdensity=readdensity,
                 srchunks=srchunks,
             )
 
         fm.plain(b'\n')
 
     fm.end()
 
 
 @command(
     b'debug-delta-find',
     cmdutil.debugrevlogopts
     + cmdutil.formatteropts
     + [
         (
             b'',
             b'source',
             b'full',
             _(b'input data feed to the process (full, storage, p1, p2, prev)'),
         ),
     ],
     _(b'-c|-m|FILE REV'),
     optionalrepo=True,
 )
 def debugdeltafind(ui, repo, arg_1, arg_2=None, source=b'full', **opts):
     """display the computation to get to a valid delta for storing REV
 
     This command will replay the process used to find the "best" delta to store
     a revision and display information about all the steps used to get to that
     result.
 
     By default, the process is fed with a the full-text for the revision. This
     can be controlled with the --source flag.
 
     The revision use the revision number of the target storage (not changelog
     revision number).
 
     note: the process is initiated from a full text of the revision to store.
     """
     opts = pycompat.byteskwargs(opts)
     if arg_2 is None:
         file_ = None
         rev = arg_1
     else:
         file_ = arg_1
         rev = arg_2
 
     rev = int(rev)
 
     revlog = cmdutil.openrevlog(repo, b'debugdeltachain', file_, opts)
     p1r, p2r = revlog.parentrevs(rev)
 
     if source == b'full':
         base_rev = nullrev
     elif source == b'storage':
         base_rev = revlog.deltaparent(rev)
     elif source == b'p1':
         base_rev = p1r
     elif source == b'p2':
         base_rev = p2r
     elif source == b'prev':
         base_rev = rev - 1
     else:
         raise error.InputError(b"invalid --source value: %s" % source)
 
     revlog_debug.debug_delta_find(ui, revlog, rev, base_rev=base_rev)
 
 
 @command(
     b'debugdirstate|debugstate',
     [
         (
             b'',
             b'nodates',
             None,
             _(b'do not display the saved mtime (DEPRECATED)'),
         ),
         (b'', b'dates', True, _(b'display the saved mtime')),
         (b'', b'datesort', None, _(b'sort by saved mtime')),
         (
             b'',
             b'docket',
             False,
             _(b'display the docket (metadata file) instead'),
         ),
         (
             b'',
             b'all',
             False,
             _(b'display dirstate-v2 tree nodes that would not exist in v1'),
         ),
     ],
     _(b'[OPTION]...'),
 )
 def debugstate(ui, repo, **opts):
     """show the contents of the current dirstate"""
 
     if opts.get("docket"):
         if not repo.dirstate._use_dirstate_v2:
             raise error.Abort(_(b'dirstate v1 does not have a docket'))
 
         docket = repo.dirstate._map.docket
         (
             start_offset,
             root_nodes,
             nodes_with_entry,
             nodes_with_copy,
             unused_bytes,
             _unused,
             ignore_pattern,
         ) = dirstateutils.v2.TREE_METADATA.unpack(docket.tree_metadata)
 
         ui.write(_(b"size of dirstate data: %d\n") % docket.data_size)
         ui.write(_(b"data file uuid: %s\n") % docket.uuid)
         ui.write(_(b"start offset of root nodes: %d\n") % start_offset)
         ui.write(_(b"number of root nodes: %d\n") % root_nodes)
         ui.write(_(b"nodes with entries: %d\n") % nodes_with_entry)
         ui.write(_(b"nodes with copies: %d\n") % nodes_with_copy)
         ui.write(_(b"number of unused bytes: %d\n") % unused_bytes)
         ui.write(
             _(b"ignore pattern hash: %s\n") % binascii.hexlify(ignore_pattern)
         )
         return
 
     nodates = not opts['dates']
     if opts.get('nodates') is not None:
         nodates = True
     datesort = opts.get('datesort')
 
     if datesort:
 
         def keyfunc(entry):
             filename, _state, _mode, _size, mtime = entry
             return (mtime, filename)
 
     else:
         keyfunc = None  # sort by filename
     entries = list(repo.dirstate._map.debug_iter(all=opts['all']))
     entries.sort(key=keyfunc)
     for entry in entries:
         filename, state, mode, size, mtime = entry
         if mtime == -1:
             timestr = b'unset               '
         elif nodates:
             timestr = b'set                 '
         else:
             timestr = time.strftime("%Y-%m-%d %H:%M:%S ", time.localtime(mtime))
             timestr = encoding.strtolocal(timestr)
         if mode & 0o20000:
             mode = b'lnk'
         else:
             mode = b'%3o' % (mode & 0o777 & ~util.umask)
         ui.write(b"%c %s %10d %s%s\n" % (state, mode, size, timestr, filename))
     for f in repo.dirstate.copies():
         ui.write(_(b"copy: %s -> %s\n") % (repo.dirstate.copied(f), f))
 
 
 @command(
     b'debugdirstateignorepatternshash',
     [],
     _(b''),
 )
 def debugdirstateignorepatternshash(ui, repo, **opts):
     """show the hash of ignore patterns stored in dirstate if v2,
     or nothing for dirstate-v2
     """
     if repo.dirstate._use_dirstate_v2:
         docket = repo.dirstate._map.docket
         hash_len = 20  # 160 bits for SHA-1
         hash_bytes = docket.tree_metadata[-hash_len:]
         ui.write(binascii.hexlify(hash_bytes) + b'\n')
 
 
 @command(
     b'debugdiscovery',
     [
         (b'', b'old', None, _(b'use old-style discovery')),
         (
             b'',
             b'nonheads',
             None,
             _(b'use old-style discovery with non-heads included'),
         ),
         (b'', b'rev', [], b'restrict discovery to this set of revs'),
         (b'', b'seed', b'12323', b'specify the random seed use for discovery'),
         (
             b'',
             b'local-as-revs',
             b"",
             b'treat local has having these revisions only',
         ),
         (
             b'',
             b'remote-as-revs',
             b"",
             b'use local as remote, with only these revisions',
         ),
     ]
     + cmdutil.remoteopts
     + cmdutil.formatteropts,
     _(b'[--rev REV] [OTHER]'),
 )
 def debugdiscovery(ui, repo, remoteurl=b"default", **opts):
     """runs the changeset discovery protocol in isolation
 
     The local peer can be "replaced" by a subset of the local repository by
     using the `--local-as-revs` flag. In the same way, the usual `remote` peer
     can be "replaced" by a subset of the local repository using the
     `--remote-as-revs` flag. This is useful to efficiently debug pathological
     discovery situations.
 
     The following developer oriented config are relevant for people playing with this command:
 
     * devel.discovery.exchange-heads=True
 
       If False, the discovery will not start with
       remote head fetching and local head querying.
 
     * devel.discovery.grow-sample=True
 
       If False, the sample size used in set discovery will not be increased
       through the process
 
     * devel.discovery.grow-sample.dynamic=True
 
       When discovery.grow-sample.dynamic is True, the default, the sample size is
       adapted to the shape of the undecided set (it is set to the max of:
       <target-size>, len(roots(undecided)), len(heads(undecided)
 
     * devel.discovery.grow-sample.rate=1.05
 
       the rate at which the sample grow
 
     * devel.discovery.randomize=True
 
       If andom sampling during discovery are deterministic. It is meant for
       integration tests.
 
     * devel.discovery.sample-size=200
 
       Control the initial size of the discovery sample
 
     * devel.discovery.sample-size.initial=100
 
       Control the initial size of the discovery for initial change
     """
     opts = pycompat.byteskwargs(opts)
     unfi = repo.unfiltered()
 
     # setup potential extra filtering
     local_revs = opts[b"local_as_revs"]
     remote_revs = opts[b"remote_as_revs"]
 
     # make sure tests are repeatable
     random.seed(int(opts[b'seed']))
 
     if not remote_revs:
         path = urlutil.get_unique_pull_path_obj(
             b'debugdiscovery', ui, remoteurl
         )
         branches = (path.branch, [])
         remote = hg.peer(repo, opts, path)
         ui.status(_(b'comparing with %s\n') % urlutil.hidepassword(path.loc))
     else:
         branches = (None, [])
         remote_filtered_revs = logcmdutil.revrange(
             unfi, [b"not (::(%s))" % remote_revs]
         )
         remote_filtered_revs = frozenset(remote_filtered_revs)
 
         def remote_func(x):
             return remote_filtered_revs
 
         repoview.filtertable[b'debug-discovery-remote-filter'] = remote_func
 
         remote = repo.peer()
         remote._repo = remote._repo.filtered(b'debug-discovery-remote-filter')
 
     if local_revs:
         local_filtered_revs = logcmdutil.revrange(
             unfi, [b"not (::(%s))" % local_revs]
         )
         local_filtered_revs = frozenset(local_filtered_revs)
 
         def local_func(x):
             return local_filtered_revs
 
         repoview.filtertable[b'debug-discovery-local-filter'] = local_func
         repo = repo.filtered(b'debug-discovery-local-filter')
 
     data = {}
     if opts.get(b'old'):
 
         def doit(pushedrevs, remoteheads, remote=remote):
             if not util.safehasattr(remote, b'branches'):
                 # enable in-client legacy support
                 remote = localrepo.locallegacypeer(remote.local())
                 if remote_revs:
                     r = remote._repo.filtered(b'debug-discovery-remote-filter')
                     remote._repo = r
             common, _in, hds = treediscovery.findcommonincoming(
                 repo, remote, force=True, audit=data
             )
             common = set(common)
             if not opts.get(b'nonheads'):
                 ui.writenoi18n(
                     b"unpruned common: %s\n"
                     % b" ".join(sorted(short(n) for n in common))
                 )
 
                 clnode = repo.changelog.node
                 common = repo.revs(b'heads(::%ln)', common)
                 common = {clnode(r) for r in common}
             return common, hds
 
     else:
 
         def doit(pushedrevs, remoteheads, remote=remote):
             nodes = None
             if pushedrevs:
                 revs = logcmdutil.revrange(repo, pushedrevs)
                 nodes = [repo[r].node() for r in revs]
             common, any, hds = setdiscovery.findcommonheads(
                 ui,
                 repo,
                 remote,
                 ancestorsof=nodes,
                 audit=data,
                 abortwhenunrelated=False,
             )
             return common, hds
 
     remoterevs, _checkout = hg.addbranchrevs(repo, remote, branches, revs=None)
     localrevs = opts[b'rev']
 
     fm = ui.formatter(b'debugdiscovery', opts)
     if fm.strict_format:
 
         @contextlib.contextmanager
         def may_capture_output():
             ui.pushbuffer()
             yield
             data[b'output'] = ui.popbuffer()
 
     else:
         may_capture_output = util.nullcontextmanager
     with may_capture_output():
         with util.timedcm('debug-discovery') as t:
             common, hds = doit(localrevs, remoterevs)
 
     # compute all statistics
     if len(common) == 1 and repo.nullid in common:
         common = set()
     heads_common = set(common)
     heads_remote = set(hds)
     heads_local = set(repo.heads())
     # note: they cannot be a local or remote head that is in common and not
     # itself a head of common.
     heads_common_local = heads_common & heads_local
     heads_common_remote = heads_common & heads_remote
     heads_common_both = heads_common & heads_remote & heads_local
 
     all = repo.revs(b'all()')
     common = repo.revs(b'::%ln', common)
     roots_common = repo.revs(b'roots(::%ld)', common)
     missing = repo.revs(b'not ::%ld', common)
     heads_missing = repo.revs(b'heads(%ld)', missing)
     roots_missing = repo.revs(b'roots(%ld)', missing)
     assert len(common) + len(missing) == len(all)
 
     initial_undecided = repo.revs(
         b'not (::%ln or %ln::)', heads_common_remote, heads_common_local
     )
     heads_initial_undecided = repo.revs(b'heads(%ld)', initial_undecided)
     roots_initial_undecided = repo.revs(b'roots(%ld)', initial_undecided)
     common_initial_undecided = initial_undecided & common
     missing_initial_undecided = initial_undecided & missing
 
     data[b'elapsed'] = t.elapsed
     data[b'nb-common-heads'] = len(heads_common)
     data[b'nb-common-heads-local'] = len(heads_common_local)
     data[b'nb-common-heads-remote'] = len(heads_common_remote)
     data[b'nb-common-heads-both'] = len(heads_common_both)
     data[b'nb-common-roots'] = len(roots_common)
     data[b'nb-head-local'] = len(heads_local)
     data[b'nb-head-local-missing'] = len(heads_local) - len(heads_common_local)
     data[b'nb-head-remote'] = len(heads_remote)
     data[b'nb-head-remote-unknown'] = len(heads_remote) - len(
         heads_common_remote
     )
     data[b'nb-revs'] = len(all)
     data[b'nb-revs-common'] = len(common)
     data[b'nb-revs-missing'] = len(missing)
     data[b'nb-missing-heads'] = len(heads_missing)
     data[b'nb-missing-roots'] = len(roots_missing)
     data[b'nb-ini_und'] = len(initial_undecided)
     data[b'nb-ini_und-heads'] = len(heads_initial_undecided)
     data[b'nb-ini_und-roots'] = len(roots_initial_undecided)
     data[b'nb-ini_und-common'] = len(common_initial_undecided)
     data[b'nb-ini_und-missing'] = len(missing_initial_undecided)
 
     fm.startitem()
     fm.data(**pycompat.strkwargs(data))
     # display discovery summary
     fm.plain(b"elapsed time:  %(elapsed)f seconds\n" % data)
     fm.plain(b"round-trips:           %(total-roundtrips)9d\n" % data)
     if b'total-round-trips-heads' in data:
         fm.plain(
             b"  round-trips-heads:    %(total-round-trips-heads)9d\n" % data
         )
     if b'total-round-trips-branches' in data:
         fm.plain(
             b"  round-trips-branches:    %(total-round-trips-branches)9d\n"
             % data
         )
     if b'total-round-trips-between' in data:
         fm.plain(
             b"  round-trips-between:    %(total-round-trips-between)9d\n" % data
         )
     fm.plain(b"queries:               %(total-queries)9d\n" % data)
     if b'total-queries-branches' in data:
         fm.plain(b"  queries-branches:    %(total-queries-branches)9d\n" % data)
     if b'total-queries-between' in data:
         fm.plain(b"  queries-between:     %(total-queries-between)9d\n" % data)
     fm.plain(b"heads summary:\n")
     fm.plain(b"  total common heads:  %(nb-common-heads)9d\n" % data)
     fm.plain(b"    also local heads:  %(nb-common-heads-local)9d\n" % data)
     fm.plain(b"    also remote heads: %(nb-common-heads-remote)9d\n" % data)
     fm.plain(b"    both:              %(nb-common-heads-both)9d\n" % data)
     fm.plain(b"  local heads:         %(nb-head-local)9d\n" % data)
     fm.plain(b"    common:            %(nb-common-heads-local)9d\n" % data)
     fm.plain(b"    missing:           %(nb-head-local-missing)9d\n" % data)
     fm.plain(b"  remote heads:        %(nb-head-remote)9d\n" % data)
     fm.plain(b"    common:            %(nb-common-heads-remote)9d\n" % data)
     fm.plain(b"    unknown:           %(nb-head-remote-unknown)9d\n" % data)
     fm.plain(b"local changesets:      %(nb-revs)9d\n" % data)
     fm.plain(b"  common:              %(nb-revs-common)9d\n" % data)
     fm.plain(b"    heads:             %(nb-common-heads)9d\n" % data)
     fm.plain(b"    roots:             %(nb-common-roots)9d\n" % data)
     fm.plain(b"  missing:             %(nb-revs-missing)9d\n" % data)
     fm.plain(b"    heads:             %(nb-missing-heads)9d\n" % data)
     fm.plain(b"    roots:             %(nb-missing-roots)9d\n" % data)
     fm.plain(b"  first undecided set: %(nb-ini_und)9d\n" % data)
     fm.plain(b"    heads:             %(nb-ini_und-heads)9d\n" % data)
     fm.plain(b"    roots:             %(nb-ini_und-roots)9d\n" % data)
     fm.plain(b"    common:            %(nb-ini_und-common)9d\n" % data)
     fm.plain(b"    missing:           %(nb-ini_und-missing)9d\n" % data)
 
     if ui.verbose:
         fm.plain(
             b"common heads: %s\n"
             % b" ".join(sorted(short(n) for n in heads_common))
         )
     fm.end()
 
 
 _chunksize = 4 << 10
 
 
 @command(
     b'debugdownload',
     [
         (b'o', b'output', b'', _(b'path')),
     ],
     optionalrepo=True,
 )
 def debugdownload(ui, repo, url, output=None, **opts):
     """download a resource using Mercurial logic and config"""
     fh = urlmod.open(ui, url, output)
 
     dest = ui
     if output:
         dest = open(output, b"wb", _chunksize)
     try:
         data = fh.read(_chunksize)
         while data:
             dest.write(data)
             data = fh.read(_chunksize)
     finally:
         if output:
             dest.close()
 
 
 @command(b'debugextensions', cmdutil.formatteropts, [], optionalrepo=True)
 def debugextensions(ui, repo, **opts):
     '''show information about active extensions'''
     opts = pycompat.byteskwargs(opts)
     exts = extensions.extensions(ui)
     hgver = util.version()
     fm = ui.formatter(b'debugextensions', opts)
     for extname, extmod in sorted(exts, key=operator.itemgetter(0)):
         isinternal = extensions.ismoduleinternal(extmod)
         extsource = None
 
         if util.safehasattr(extmod, '__file__'):
             extsource = pycompat.fsencode(extmod.__file__)
         elif getattr(sys, 'oxidized', False):
             extsource = pycompat.sysexecutable
         if isinternal:
             exttestedwith = []  # never expose magic string to users
         else:
             exttestedwith = getattr(extmod, 'testedwith', b'').split()
         extbuglink = getattr(extmod, 'buglink', None)
 
         fm.startitem()
 
         if ui.quiet or ui.verbose:
             fm.write(b'name', b'%s\n', extname)
         else:
             fm.write(b'name', b'%s', extname)
             if isinternal or hgver in exttestedwith:
                 fm.plain(b'\n')
             elif not exttestedwith:
                 fm.plain(_(b' (untested!)\n'))
             else:
                 lasttestedversion = exttestedwith[-1]
                 fm.plain(b' (%s!)\n' % lasttestedversion)
 
         fm.condwrite(
             ui.verbose and extsource,
             b'source',
             _(b'  location: %s\n'),
             extsource or b"",
         )
 
         if ui.verbose:
             fm.plain(_(b'  bundled: %s\n') % [b'no', b'yes'][isinternal])
         fm.data(bundled=isinternal)
 
         fm.condwrite(
             ui.verbose and exttestedwith,
             b'testedwith',
             _(b'  tested with: %s\n'),
             fm.formatlist(exttestedwith, name=b'ver'),
         )
 
         fm.condwrite(
             ui.verbose and extbuglink,
             b'buglink',
             _(b'  bug reporting: %s\n'),
             extbuglink or b"",
         )
 
     fm.end()
 
 
 @command(
     b'debugfileset',
     [
         (
             b'r',
             b'rev',
             b'',
             _(b'apply the filespec on this revision'),
             _(b'REV'),
         ),
         (
             b'',
             b'all-files',
             False,
             _(b'test files from all revisions and working directory'),
         ),
         (
             b's',
             b'show-matcher',
             None,
             _(b'print internal representation of matcher'),
         ),
         (
             b'p',
             b'show-stage',
             [],
             _(b'print parsed tree at the given stage'),
             _(b'NAME'),
         ),
     ],
     _(b'[-r REV] [--all-files] [OPTION]... FILESPEC'),
 )
 def debugfileset(ui, repo, expr, **opts):
     '''parse and apply a fileset specification'''
     from . import fileset
 
     fileset.symbols  # force import of fileset so we have predicates to optimize
     opts = pycompat.byteskwargs(opts)
     ctx = logcmdutil.revsingle(repo, opts.get(b'rev'), None)
 
     stages = [
         (b'parsed', pycompat.identity),
         (b'analyzed', filesetlang.analyze),
         (b'optimized', filesetlang.optimize),
     ]
     stagenames = {n for n, f in stages}
 
     showalways = set()
     if ui.verbose and not opts[b'show_stage']:
         # show parsed tree by --verbose (deprecated)
         showalways.add(b'parsed')
     if opts[b'show_stage'] == [b'all']:
         showalways.update(stagenames)
     else:
         for n in opts[b'show_stage']:
             if n not in stagenames:
                 raise error.Abort(_(b'invalid stage name: %s') % n)
         showalways.update(opts[b'show_stage'])
 
     tree = filesetlang.parse(expr)
     for n, f in stages:
         tree = f(tree)
         if n in showalways:
             if opts[b'show_stage'] or n != b'parsed':
                 ui.write(b"* %s:\n" % n)
             ui.write(filesetlang.prettyformat(tree), b"\n")
 
     files = set()
     if opts[b'all_files']:
         for r in repo:
             c = repo[r]
             files.update(c.files())
             files.update(c.substate)
     if opts[b'all_files'] or ctx.rev() is None:
         wctx = repo[None]
         files.update(
             repo.dirstate.walk(
                 scmutil.matchall(repo),
                 subrepos=list(wctx.substate),
                 unknown=True,
                 ignored=True,
             )
         )
         files.update(wctx.substate)
     else:
         files.update(ctx.files())
         files.update(ctx.substate)
 
     m = ctx.matchfileset(repo.getcwd(), expr)
     if opts[b'show_matcher'] or (opts[b'show_matcher'] is None and ui.verbose):
         ui.writenoi18n(b'* matcher:\n', stringutil.prettyrepr(m), b'\n')
     for f in sorted(files):
         if not m(f):
             continue
         ui.write(b"%s\n" % f)
 
 
 @command(
     b"debug-repair-issue6528",
     [
         (
             b'',
             b'to-report',
             b'',
             _(b'build a report of affected revisions to this file'),
             _(b'FILE'),
         ),
         (
             b'',
             b'from-report',
             b'',
             _(b'repair revisions listed in this report file'),
             _(b'FILE'),
         ),
         (
             b'',
             b'paranoid',
             False,
             _(b'check that both detection methods do the same thing'),
         ),
     ]
     + cmdutil.dryrunopts,
 )
 def debug_repair_issue6528(ui, repo, **opts):
     """find affected revisions and repair them. See issue6528 for more details.
 
     The `--to-report` and `--from-report` flags allow you to cache and reuse the
     computation of affected revisions for a given repository across clones.
     The report format is line-based (with empty lines ignored):
 
     ```
     <ascii-hex of the affected revision>,... <unencoded filelog index filename>
     ```
 
     There can be multiple broken revisions per filelog, they are separated by
     a comma with no spaces. The only space is between the revision(s) and the
     filename.
 
     Note that this does *not* mean that this repairs future affected revisions,
     that needs a separate fix at the exchange level that was introduced in
     Mercurial 5.9.1.
 
     There is a `--paranoid` flag to test that the fast implementation is correct
     by checking it against the slow implementation. Since this matter is quite
     urgent and testing every edge-case is probably quite costly, we use this
     method to test on large repositories as a fuzzing method of sorts.
     """
     cmdutil.check_incompatible_arguments(
         opts, 'to_report', ['from_report', 'dry_run']
     )
     dry_run = opts.get('dry_run')
     to_report = opts.get('to_report')
     from_report = opts.get('from_report')
     paranoid = opts.get('paranoid')
     # TODO maybe add filelog pattern and revision pattern parameters to help
     # narrow down the search for users that know what they're looking for?
 
     if requirements.REVLOGV1_REQUIREMENT not in repo.requirements:
         msg = b"can only repair revlogv1 repositories, v2 is not affected"
         raise error.Abort(_(msg))
 
     rewrite.repair_issue6528(
         ui,
         repo,
         dry_run=dry_run,
         to_report=to_report,
         from_report=from_report,
         paranoid=paranoid,
     )
 
 
 @command(b'debugformat', [] + cmdutil.formatteropts)
 def debugformat(ui, repo, **opts):
     """display format information about the current repository
 
     Use --verbose to get extra information about current config value and
     Mercurial default."""
     opts = pycompat.byteskwargs(opts)
     maxvariantlength = max(len(fv.name) for fv in upgrade.allformatvariant)
     maxvariantlength = max(len(b'format-variant'), maxvariantlength)
 
     def makeformatname(name):
         return b'%s:' + (b' ' * (maxvariantlength - len(name)))
 
     fm = ui.formatter(b'debugformat', opts)
     if fm.isplain():
 
         def formatvalue(value):
             if util.safehasattr(value, b'startswith'):
                 return value
             if value:
                 return b'yes'
             else:
                 return b'no'
 
     else:
         formatvalue = pycompat.identity
 
     fm.plain(b'format-variant')
     fm.plain(b' ' * (maxvariantlength - len(b'format-variant')))
     fm.plain(b' repo')
     if ui.verbose:
         fm.plain(b' config default')
     fm.plain(b'\n')
     for fv in upgrade.allformatvariant:
         fm.startitem()
         repovalue = fv.fromrepo(repo)
         configvalue = fv.fromconfig(repo)
 
         if repovalue != configvalue:
             namelabel = b'formatvariant.name.mismatchconfig'
             repolabel = b'formatvariant.repo.mismatchconfig'
         elif repovalue != fv.default:
             namelabel = b'formatvariant.name.mismatchdefault'
             repolabel = b'formatvariant.repo.mismatchdefault'
         else:
             namelabel = b'formatvariant.name.uptodate'
             repolabel = b'formatvariant.repo.uptodate'
 
         fm.write(b'name', makeformatname(fv.name), fv.name, label=namelabel)
         fm.write(b'repo', b' %3s', formatvalue(repovalue), label=repolabel)
         if fv.default != configvalue:
             configlabel = b'formatvariant.config.special'
         else:
             configlabel = b'formatvariant.config.default'
         fm.condwrite(
             ui.verbose,
             b'config',
             b' %6s',
             formatvalue(configvalue),
             label=configlabel,
         )
         fm.condwrite(
             ui.verbose,
             b'default',
             b' %7s',
             formatvalue(fv.default),
             label=b'formatvariant.default',
         )
         fm.plain(b'\n')
     fm.end()
 
 
 @command(b'debugfsinfo', [], _(b'[PATH]'), norepo=True)
 def debugfsinfo(ui, path=b"."):
     """show information detected about current filesystem"""
     ui.writenoi18n(b'path: %s\n' % path)
     ui.writenoi18n(
         b'mounted on: %s\n' % (util.getfsmountpoint(path) or b'(unknown)')
     )
     ui.writenoi18n(b'exec: %s\n' % (util.checkexec(path) and b'yes' or b'no'))
     ui.writenoi18n(b'fstype: %s\n' % (util.getfstype(path) or b'(unknown)'))
     ui.writenoi18n(
         b'symlink: %s\n' % (util.checklink(path) and b'yes' or b'no')
     )
     ui.writenoi18n(
         b'hardlink: %s\n' % (util.checknlink(path) and b'yes' or b'no')
     )
     casesensitive = b'(unknown)'
     try:
         with pycompat.namedtempfile(prefix=b'.debugfsinfo', dir=path) as f:
             casesensitive = util.fscasesensitive(f.name) and b'yes' or b'no'
     except OSError:
         pass
     ui.writenoi18n(b'case-sensitive: %s\n' % casesensitive)
 
 
 @command(
     b'debuggetbundle',
     [
         (b'H', b'head', [], _(b'id of head node'), _(b'ID')),
         (b'C', b'common', [], _(b'id of common node'), _(b'ID')),
         (
             b't',
             b'type',
             b'bzip2',
             _(b'bundle compression type to use'),
             _(b'TYPE'),
         ),
     ],
     _(b'REPO FILE [-H|-C ID]...'),
     norepo=True,
 )
 def debuggetbundle(ui, repopath, bundlepath, head=None, common=None, **opts):
     """retrieves a bundle from a repo
 
     Every ID must be a full-length hex node id string. Saves the bundle to the
     given file.
     """
     opts = pycompat.byteskwargs(opts)
     repo = hg.peer(ui, opts, repopath)
     if not repo.capable(b'getbundle'):
         raise error.Abort(b"getbundle() not supported by target repository")
     args = {}
     if common:
         args['common'] = [bin(s) for s in common]
     if head:
         args['heads'] = [bin(s) for s in head]
     # TODO: get desired bundlecaps from command line.
     args['bundlecaps'] = None
     bundle = repo.getbundle(b'debug', **args)
 
     bundletype = opts.get(b'type', b'bzip2').lower()
     btypes = {
         b'none': b'HG10UN',
         b'bzip2': b'HG10BZ',
         b'gzip': b'HG10GZ',
         b'bundle2': b'HG20',
     }
     bundletype = btypes.get(bundletype)
     if bundletype not in bundle2.bundletypes:
         raise error.Abort(_(b'unknown bundle type specified with --type'))
     bundle2.writebundle(ui, bundle, bundlepath, bundletype)
 
 
 @command(b'debugignore', [], b'[FILE]')
 def debugignore(ui, repo, *files, **opts):
     """display the combined ignore pattern and information about ignored files
 
     With no argument display the combined ignore pattern.
 
     Given space separated file names, shows if the given file is ignored and
     if so, show the ignore rule (file and line number) that matched it.
     """
     ignore = repo.dirstate._ignore
     if not files:
         # Show all the patterns
         ui.write(b"%s\n" % pycompat.byterepr(ignore))
     else:
         m = scmutil.match(repo[None], pats=files)
         uipathfn = scmutil.getuipathfn(repo, legacyrelativevalue=True)
         for f in m.files():
             nf = util.normpath(f)
             ignored = None
             ignoredata = None
             if nf != b'.':
                 if ignore(nf):
                     ignored = nf
                     ignoredata = repo.dirstate._ignorefileandline(nf)
                 else:
                     for p in pathutil.finddirs(nf):
                         if ignore(p):
                             ignored = p
                             ignoredata = repo.dirstate._ignorefileandline(p)
                             break
             if ignored:
                 if ignored == nf:
                     ui.write(_(b"%s is ignored\n") % uipathfn(f))
                 else:
                     ui.write(
                         _(
                             b"%s is ignored because of "
                             b"containing directory %s\n"
                         )
                         % (uipathfn(f), ignored)
                     )
                 ignorefile, lineno, line = ignoredata
                 ui.write(
                     _(b"(ignore rule in %s, line %d: '%s')\n")
                     % (ignorefile, lineno, line)
                 )
             else:
                 ui.write(_(b"%s is not ignored\n") % uipathfn(f))
 
 
 @command(
     b'debug-revlog-index|debugindex',
     cmdutil.debugrevlogopts + cmdutil.formatteropts,
     _(b'-c|-m|FILE'),
 )
 def debugindex(ui, repo, file_=None, **opts):
     """dump index data for a revlog"""
     opts = pycompat.byteskwargs(opts)
     store = cmdutil.openstorage(repo, b'debugindex', file_, opts)
 
     fm = ui.formatter(b'debugindex', opts)
 
     revlog = getattr(store, b'_revlog', store)
 
     return revlog_debug.debug_index(
         ui,
         repo,
         formatter=fm,
         revlog=revlog,
         full_node=ui.debugflag,
     )
 
 
 @command(
     b'debugindexdot',
     cmdutil.debugrevlogopts,
     _(b'-c|-m|FILE'),
     optionalrepo=True,
 )
 def debugindexdot(ui, repo, file_=None, **opts):
     """dump an index DAG as a graphviz dot file"""
     opts = pycompat.byteskwargs(opts)
     r = cmdutil.openstorage(repo, b'debugindexdot', file_, opts)
     ui.writenoi18n(b"digraph G {\n")
     for i in r:
         node = r.node(i)
         pp = r.parents(node)
         ui.write(b"\t%d -> %d\n" % (r.rev(pp[0]), i))
         if pp[1] != repo.nullid:
             ui.write(b"\t%d -> %d\n" % (r.rev(pp[1]), i))
     ui.write(b"}\n")
 
 
 @command(b'debugindexstats', [])
 def debugindexstats(ui, repo):
     """show stats related to the changelog index"""
     repo.changelog.shortest(repo.nullid, 1)
     index = repo.changelog.index
     if not util.safehasattr(index, b'stats'):
         raise error.Abort(_(b'debugindexstats only works with native code'))
     for k, v in sorted(index.stats().items()):
         ui.write(b'%s: %d\n' % (k, v))
 
 
 @command(b'debuginstall', [] + cmdutil.formatteropts, b'', norepo=True)
 def debuginstall(ui, **opts):
     """test Mercurial installation
 
     Returns 0 on success.
     """
     opts = pycompat.byteskwargs(opts)
 
     problems = 0
 
     fm = ui.formatter(b'debuginstall', opts)
     fm.startitem()
 
     # encoding might be unknown or wrong. don't translate these messages.
     fm.write(b'encoding', b"checking encoding (%s)...\n", encoding.encoding)
     err = None
     try:
         codecs.lookup(pycompat.sysstr(encoding.encoding))
     except LookupError as inst:
         err = stringutil.forcebytestr(inst)
         problems += 1
     fm.condwrite(
         err,
         b'encodingerror',
         b" %s\n (check that your locale is properly set)\n",
         err,
     )
 
     # Python
     pythonlib = None
     if util.safehasattr(os, '__file__'):
         pythonlib = os.path.dirname(pycompat.fsencode(os.__file__))
     elif getattr(sys, 'oxidized', False):
         pythonlib = pycompat.sysexecutable
 
     fm.write(
         b'pythonexe',
         _(b"checking Python executable (%s)\n"),
         pycompat.sysexecutable or _(b"unknown"),
     )
     fm.write(
         b'pythonimplementation',
         _(b"checking Python implementation (%s)\n"),
         pycompat.sysbytes(platform.python_implementation()),
     )
     fm.write(
         b'pythonver',
         _(b"checking Python version (%s)\n"),
         (b"%d.%d.%d" % sys.version_info[:3]),
     )
     fm.write(
         b'pythonlib',
         _(b"checking Python lib (%s)...\n"),
         pythonlib or _(b"unknown"),
     )
 
     try:
         from . import rustext  # pytype: disable=import-error
 
         rustext.__doc__  # trigger lazy import
     except ImportError:
         rustext = None
 
     security = set(sslutil.supportedprotocols)
     if sslutil.hassni:
         security.add(b'sni')
 
     fm.write(
         b'pythonsecurity',
         _(b"checking Python security support (%s)\n"),
         fm.formatlist(sorted(security), name=b'protocol', fmt=b'%s', sep=b','),
     )
 
     # These are warnings, not errors. So don't increment problem count. This
     # may change in the future.
     if b'tls1.2' not in security:
         fm.plain(
             _(
                 b'  TLS 1.2 not supported by Python install; '
                 b'network connections lack modern security\n'
             )
         )
     if b'sni' not in security:
         fm.plain(
             _(
                 b'  SNI not supported by Python install; may have '
                 b'connectivity issues with some servers\n'
             )
         )
 
     fm.plain(
         _(
             b"checking Rust extensions (%s)\n"
             % (b'missing' if rustext is None else b'installed')
         ),
     )
 
     # TODO print CA cert info
 
     # hg version
     hgver = util.version()
     fm.write(
         b'hgver', _(b"checking Mercurial version (%s)\n"), hgver.split(b'+')[0]
     )
     fm.write(
         b'hgverextra',
         _(b"checking Mercurial custom build (%s)\n"),
         b'+'.join(hgver.split(b'+')[1:]),
     )
 
     # compiled modules
     hgmodules = None
     if util.safehasattr(sys.modules[__name__], '__file__'):
         hgmodules = os.path.dirname(pycompat.fsencode(__file__))
     elif getattr(sys, 'oxidized', False):
         hgmodules = pycompat.sysexecutable
 
     fm.write(
         b'hgmodulepolicy', _(b"checking module policy (%s)\n"), policy.policy
     )
     fm.write(
         b'hgmodules',
         _(b"checking installed modules (%s)...\n"),
         hgmodules or _(b"unknown"),
     )
 
     rustandc = policy.policy in (b'rust+c', b'rust+c-allow')
     rustext = rustandc  # for now, that's the only case
     cext = policy.policy in (b'c', b'allow') or rustandc
     nopure = cext or rustext
     if nopure:
         err = None
         try:
             if cext:
                 from .cext import (  # pytype: disable=import-error
                     base85,
                     bdiff,
                     mpatch,
                     osutil,
                 )
 
                 # quiet pyflakes
                 dir(bdiff), dir(mpatch), dir(base85), dir(osutil)
             if rustext:
                 from .rustext import (  # pytype: disable=import-error
                     ancestor,
                     dirstate,
                 )
 
                 dir(ancestor), dir(dirstate)  # quiet pyflakes
         except Exception as inst:
             err = stringutil.forcebytestr(inst)
             problems += 1
         fm.condwrite(err, b'extensionserror', b" %s\n", err)
 
     compengines = util.compengines._engines.values()
     fm.write(
         b'compengines',
         _(b'checking registered compression engines (%s)\n'),
         fm.formatlist(
             sorted(e.name() for e in compengines),
             name=b'compengine',
             fmt=b'%s',
             sep=b', ',
         ),
     )
     fm.write(
         b'compenginesavail',
         _(b'checking available compression engines (%s)\n'),
         fm.formatlist(
             sorted(e.name() for e in compengines if e.available()),
             name=b'compengine',
             fmt=b'%s',
             sep=b', ',
         ),
     )
     wirecompengines = compression.compengines.supportedwireengines(
         compression.SERVERROLE
     )
     fm.write(
         b'compenginesserver',
         _(
             b'checking available compression engines '
             b'for wire protocol (%s)\n'
         ),
         fm.formatlist(
             [e.name() for e in wirecompengines if e.wireprotosupport()],
             name=b'compengine',
             fmt=b'%s',
             sep=b', ',
         ),
     )
     re2 = b'missing'
-    if util._re2:
+    if util.has_re2():
         re2 = b'available'
     fm.plain(_(b'checking "re2" regexp engine (%s)\n') % re2)
     fm.data(re2=bool(util._re2))
 
     # templates
     p = templater.templatedir()
     fm.write(b'templatedirs', b'checking templates (%s)...\n', p or b'')
     fm.condwrite(not p, b'', _(b" no template directories found\n"))
     if p:
         (m, fp) = templater.try_open_template(b"map-cmdline.default")
         if m:
             # template found, check if it is working
             err = None
             try:
                 templater.templater.frommapfile(m)
             except Exception as inst:
                 err = stringutil.forcebytestr(inst)
                 p = None
             fm.condwrite(err, b'defaulttemplateerror', b" %s\n", err)
         else:
             p = None
         fm.condwrite(
             p, b'defaulttemplate', _(b"checking default template (%s)\n"), m
         )
         fm.condwrite(
             not m,
             b'defaulttemplatenotfound',
             _(b" template '%s' not found\n"),
             b"default",
         )
     if not p:
         problems += 1
     fm.condwrite(
         not p, b'', _(b" (templates seem to have been installed incorrectly)\n")
     )
 
     # editor
     editor = ui.geteditor()
     editor = util.expandpath(editor)
     editorbin = procutil.shellsplit(editor)[0]
     fm.write(b'editor', _(b"checking commit editor... (%s)\n"), editorbin)
     cmdpath = procutil.findexe(editorbin)
     fm.condwrite(
         not cmdpath and editor == b'vi',
         b'vinotfound',
         _(
             b" No commit editor set and can't find %s in PATH\n"
             b" (specify a commit editor in your configuration"
             b" file)\n"
         ),
         not cmdpath and editor == b'vi' and editorbin,
     )
     fm.condwrite(
         not cmdpath and editor != b'vi',
         b'editornotfound',
         _(
             b" Can't find editor '%s' in PATH\n"
             b" (specify a commit editor in your configuration"
             b" file)\n"
         ),
         not cmdpath and editorbin,
     )
     if not cmdpath and editor != b'vi':
         problems += 1
 
     # check username
     username = None
     err = None
     try:
         username = ui.username()
     except error.Abort as e:
         err = e.message
         problems += 1
 
     fm.condwrite(
         username, b'username', _(b"checking username (%s)\n"), username
     )
     fm.condwrite(
         err,
         b'usernameerror',
         _(
             b"checking username...\n %s\n"
             b" (specify a username in your configuration file)\n"
         ),
         err,
     )
 
     for name, mod in extensions.extensions():
         handler = getattr(mod, 'debuginstall', None)
         if handler is not None:
             problems += handler(ui, fm)
 
     fm.condwrite(not problems, b'', _(b"no problems detected\n"))
     if not problems:
         fm.data(problems=problems)
     fm.condwrite(
         problems,
         b'problems',
         _(b"%d problems detected, please check your install!\n"),
         problems,
     )
     fm.end()
 
     return problems
 
 
 @command(b'debugknown', [], _(b'REPO ID...'), norepo=True)
 def debugknown(ui, repopath, *ids, **opts):
     """test whether node ids are known to a repo
 
     Every ID must be a full-length hex node id string. Returns a list of 0s
     and 1s indicating unknown/known.
     """
     opts = pycompat.byteskwargs(opts)
     repo = hg.peer(ui, opts, repopath)
     if not repo.capable(b'known'):
         raise error.Abort(b"known() not supported by target repository")
     flags = repo.known([bin(s) for s in ids])
     ui.write(b"%s\n" % (b"".join([f and b"1" or b"0" for f in flags])))
 
 
 @command(b'debuglabelcomplete', [], _(b'LABEL...'))
 def debuglabelcomplete(ui, repo, *args):
     '''backwards compatibility with old bash completion scripts (DEPRECATED)'''
     debugnamecomplete(ui, repo, *args)
 
 
 @command(
     b'debuglocks',
     [
         (b'L', b'force-free-lock', None, _(b'free the store lock (DANGEROUS)')),
         (
             b'W',
             b'force-free-wlock',
             None,
             _(b'free the working state lock (DANGEROUS)'),
         ),
         (b's', b'set-lock', None, _(b'set the store lock until stopped')),
         (
             b'S',
             b'set-wlock',
             None,
             _(b'set the working state lock until stopped'),
         ),
     ],
     _(b'[OPTION]...'),
 )
 def debuglocks(ui, repo, **opts):
     """show or modify state of locks
 
     By default, this command will show which locks are held. This
     includes the user and process holding the lock, the amount of time
     the lock has been held, and the machine name where the process is
     running if it's not local.
 
     Locks protect the integrity of Mercurial's data, so should be
     treated with care. System crashes or other interruptions may cause
     locks to not be properly released, though Mercurial will usually
     detect and remove such stale locks automatically.
 
     However, detecting stale locks may not always be possible (for
     instance, on a shared filesystem). Removing locks may also be
     blocked by filesystem permissions.
 
     Setting a lock will prevent other commands from changing the data.
     The command will wait until an interruption (SIGINT, SIGTERM, ...) occurs.
     The set locks are removed when the command exits.
 
     Returns 0 if no locks are held.
 
     """
 
     if opts.get('force_free_lock'):
         repo.svfs.tryunlink(b'lock')
     if opts.get('force_free_wlock'):
         repo.vfs.tryunlink(b'wlock')
     if opts.get('force_free_lock') or opts.get('force_free_wlock'):
         return 0
 
     locks = []
     try:
         if opts.get('set_wlock'):
             try:
                 locks.append(repo.wlock(False))
             except error.LockHeld:
                 raise error.Abort(_(b'wlock is already held'))
         if opts.get('set_lock'):
             try:
                 locks.append(repo.lock(False))
             except error.LockHeld:
                 raise error.Abort(_(b'lock is already held'))
         if len(locks):
             try:
                 if ui.interactive():
                     prompt = _(b"ready to release the lock (y)? $$ &Yes")
                     ui.promptchoice(prompt)
                 else:
                     msg = b"%d locks held, waiting for signal\n"
                     msg %= len(locks)
                     ui.status(msg)
                     while True:  # XXX wait for a signal
                         time.sleep(0.1)
             except KeyboardInterrupt:
                 msg = b"signal-received releasing locks\n"
                 ui.status(msg)
             return 0
     finally:
         release(*locks)
 
     now = time.time()
     held = 0
 
     def report(vfs, name, method):
         # this causes stale locks to get reaped for more accurate reporting
         try:
             l = method(False)
         except error.LockHeld:
             l = None
 
         if l:
             l.release()
         else:
             try:
                 st = vfs.lstat(name)
                 age = now - st[stat.ST_MTIME]
                 user = util.username(st.st_uid)
                 locker = vfs.readlock(name)
                 if b":" in locker:
                     host, pid = locker.split(b':')
                     if host == socket.gethostname():
                         locker = b'user %s, process %s' % (user or b'None', pid)
                     else:
                         locker = b'user %s, process %s, host %s' % (
                             user or b'None',
                             pid,
                             host,
                         )
                 ui.writenoi18n(b"%-6s %s (%ds)\n" % (name + b":", locker, age))
                 return 1
             except FileNotFoundError:
                 pass
 
         ui.writenoi18n(b"%-6s free\n" % (name + b":"))
         return 0
 
     held += report(repo.svfs, b"lock", repo.lock)
     held += report(repo.vfs, b"wlock", repo.wlock)
 
     return held
 
 
 @command(
     b'debugmanifestfulltextcache',
     [
         (b'', b'clear', False, _(b'clear the cache')),
         (
             b'a',
             b'add',
             [],
             _(b'add the given manifest nodes to the cache'),
             _(b'NODE'),
         ),
     ],
     b'',
 )
 def debugmanifestfulltextcache(ui, repo, add=(), **opts):
     """show, clear or amend the contents of the manifest fulltext cache"""
 
     def getcache():
         r = repo.manifestlog.getstorage(b'')
         try:
             return r._fulltextcache
         except AttributeError:
             msg = _(
                 b"Current revlog implementation doesn't appear to have a "
                 b"manifest fulltext cache\n"
             )
             raise error.Abort(msg)
 
     if opts.get('clear'):
         with repo.wlock():
             cache = getcache()
             cache.clear(clear_persisted_data=True)
             return
 
     if add:
         with repo.wlock():
             m = repo.manifestlog
             store = m.getstorage(b'')
             for n in add:
                 try:
                     manifest = m[store.lookup(n)]
                 except error.LookupError as e:
                     raise error.Abort(
                         bytes(e), hint=b"Check your manifest node id"
                     )
                 manifest.read()  # stores revisision in cache too
             return
 
     cache = getcache()
     if not len(cache):
         ui.write(_(b'cache empty\n'))
     else:
         ui.write(
             _(
                 b'cache contains %d manifest entries, in order of most to '
                 b'least recent:\n'
             )
             % (len(cache),)
         )
         totalsize = 0
         for nodeid in cache:
             # Use cache.get to not update the LRU order
             data = cache.peek(nodeid)
             size = len(data)
             totalsize += size + 24  # 20 bytes nodeid, 4 bytes size
             ui.write(
                 _(b'id: %s, size %s\n') % (hex(nodeid), util.bytecount(size))
             )
         ondisk = cache._opener.stat(b'manifestfulltextcache').st_size
         ui.write(
             _(b'total cache data size %s, on-disk %s\n')
             % (util.bytecount(totalsize), util.bytecount(ondisk))
         )
 
 
 @command(b'debugmergestate', [] + cmdutil.templateopts, b'')
 def debugmergestate(ui, repo, *args, **opts):
     """print merge state
 
     Use --verbose to print out information about whether v1 or v2 merge state
     was chosen."""
 
     if ui.verbose:
         ms = mergestatemod.mergestate(repo)
 
         # sort so that reasonable information is on top
         v1records = ms._readrecordsv1()
         v2records = ms._readrecordsv2()
 
         if not v1records and not v2records:
             pass
         elif not v2records:
             ui.writenoi18n(b'no version 2 merge state\n')
         elif ms._v1v2match(v1records, v2records):
             ui.writenoi18n(b'v1 and v2 states match: using v2\n')
         else:
             ui.writenoi18n(b'v1 and v2 states mismatch: using v1\n')
 
     opts = pycompat.byteskwargs(opts)
     if not opts[b'template']:
         opts[b'template'] = (
             b'{if(commits, "", "no merge state found\n")}'
             b'{commits % "{name}{if(label, " ({label})")}: {node}\n"}'
             b'{files % "file: {path} (state \\"{state}\\")\n'
             b'{if(local_path, "'
             b'  local path: {local_path} (hash {local_key}, flags \\"{local_flags}\\")\n'
             b'  ancestor path: {ancestor_path} (node {ancestor_node})\n'
             b'  other path: {other_path} (node {other_node})\n'
             b'")}'
             b'{if(rename_side, "'
             b'  rename side: {rename_side}\n'
             b'  renamed path: {renamed_path}\n'
             b'")}'
             b'{extras % "  extra: {key} = {value}\n"}'
             b'"}'
             b'{extras % "extra: {file} ({key} = {value})\n"}'
         )
 
     ms = mergestatemod.mergestate.read(repo)
 
     fm = ui.formatter(b'debugmergestate', opts)
     fm.startitem()
 
     fm_commits = fm.nested(b'commits')
     if ms.active():
         for name, node, label_index in (
             (b'local', ms.local, 0),
             (b'other', ms.other, 1),
         ):
             fm_commits.startitem()
             fm_commits.data(name=name)
             fm_commits.data(node=hex(node))
             if ms._labels and len(ms._labels) > label_index:
                 fm_commits.data(label=ms._labels[label_index])
     fm_commits.end()
 
     fm_files = fm.nested(b'files')
     if ms.active():
         for f in ms:
             fm_files.startitem()
             fm_files.data(path=f)
             state = ms._state[f]
             fm_files.data(state=state[0])
             if state[0] in (
                 mergestatemod.MERGE_RECORD_UNRESOLVED,
                 mergestatemod.MERGE_RECORD_RESOLVED,
             ):
                 fm_files.data(local_key=state[1])
                 fm_files.data(local_path=state[2])
                 fm_files.data(ancestor_path=state[3])
                 fm_files.data(ancestor_node=state[4])
                 fm_files.data(other_path=state[5])
                 fm_files.data(other_node=state[6])
                 fm_files.data(local_flags=state[7])
             elif state[0] in (
                 mergestatemod.MERGE_RECORD_UNRESOLVED_PATH,
                 mergestatemod.MERGE_RECORD_RESOLVED_PATH,
             ):
                 fm_files.data(renamed_path=state[1])
                 fm_files.data(rename_side=state[2])
             fm_extras = fm_files.nested(b'extras')
             for k, v in sorted(ms.extras(f).items()):
                 fm_extras.startitem()
                 fm_extras.data(key=k)
                 fm_extras.data(value=v)
             fm_extras.end()
 
     fm_files.end()
 
     fm_extras = fm.nested(b'extras')
     for f, d in sorted(ms.allextras().items()):
         if f in ms:
             # If file is in mergestate, we have already processed it's extras
             continue
         for k, v in d.items():
             fm_extras.startitem()
             fm_extras.data(file=f)
             fm_extras.data(key=k)
             fm_extras.data(value=v)
     fm_extras.end()
 
     fm.end()
 
 
 @command(b'debugnamecomplete', [], _(b'NAME...'))
 def debugnamecomplete(ui, repo, *args):
     '''complete "names" - tags, open branch names, bookmark names'''
 
     names = set()
     # since we previously only listed open branches, we will handle that
     # specially (after this for loop)
     for name, ns in repo.names.items():
         if name != b'branches':
             names.update(ns.listnames(repo))
     names.update(
         tag
         for (tag, heads, tip, closed) in repo.branchmap().iterbranches()
         if not closed
     )
     completions = set()
     if not args:
         args = [b'']
     for a in args:
         completions.update(n for n in names if n.startswith(a))
     ui.write(b'\n'.join(sorted(completions)))
     ui.write(b'\n')
 
 
 @command(
     b'debugnodemap',
     [
         (
             b'',
             b'dump-new',
             False,
             _(b'write a (new) persistent binary nodemap on stdout'),
         ),
         (b'', b'dump-disk', False, _(b'dump on-disk data on stdout')),
         (
             b'',
             b'check',
             False,
             _(b'check that the data on disk data are correct.'),
         ),
         (
             b'',
             b'metadata',
             False,
             _(b'display the on disk meta data for the nodemap'),
         ),
     ],
 )
 def debugnodemap(ui, repo, **opts):
     """write and inspect on disk nodemap"""
     if opts['dump_new']:
         unfi = repo.unfiltered()
         cl = unfi.changelog
         if util.safehasattr(cl.index, "nodemap_data_all"):
             data = cl.index.nodemap_data_all()
         else:
             data = nodemap.persistent_data(cl.index)
         ui.write(data)
     elif opts['dump_disk']:
         unfi = repo.unfiltered()
         cl = unfi.changelog
         nm_data = nodemap.persisted_data(cl)
         if nm_data is not None:
             docket, data = nm_data
             ui.write(data[:])
     elif opts['check']:
         unfi = repo.unfiltered()
         cl = unfi.changelog
         nm_data = nodemap.persisted_data(cl)
         if nm_data is not None:
             docket, data = nm_data
             return nodemap.check_data(ui, cl.index, data)
     elif opts['metadata']:
         unfi = repo.unfiltered()
         cl = unfi.changelog
         nm_data = nodemap.persisted_data(cl)
         if nm_data is not None:
             docket, data = nm_data
             ui.write((b"uid: %s\n") % docket.uid)
             ui.write((b"tip-rev: %d\n") % docket.tip_rev)
             ui.write((b"tip-node: %s\n") % hex(docket.tip_node))
             ui.write((b"data-length: %d\n") % docket.data_length)
             ui.write((b"data-unused: %d\n") % docket.data_unused)
             unused_perc = docket.data_unused * 100.0 / docket.data_length
             ui.write((b"data-unused: %2.3f%%\n") % unused_perc)
 
 
 @command(
     b'debugobsolete',
     [
         (b'', b'flags', 0, _(b'markers flag')),
         (
             b'',
             b'record-parents',
             False,
             _(b'record parent information for the precursor'),
         ),
         (b'r', b'rev', [], _(b'display markers relevant to REV')),
         (
             b'',
             b'exclusive',
             False,
             _(b'restrict display to markers only relevant to REV'),
         ),
         (b'', b'index', False, _(b'display index of the marker')),
         (b'', b'delete', [], _(b'delete markers specified by indices')),
     ]
     + cmdutil.commitopts2
     + cmdutil.formatteropts,
     _(b'[OBSOLETED [REPLACEMENT ...]]'),
 )
 def debugobsolete(ui, repo, precursor=None, *successors, **opts):
     """create arbitrary obsolete marker
 
     With no arguments, displays the list of obsolescence markers."""
 
     opts = pycompat.byteskwargs(opts)
 
     def parsenodeid(s):
         try:
             # We do not use revsingle/revrange functions here to accept
             # arbitrary node identifiers, possibly not present in the
             # local repository.
             n = bin(s)
             if len(n) != repo.nodeconstants.nodelen:
                 raise ValueError
             return n
         except ValueError:
             raise error.InputError(
                 b'changeset references must be full hexadecimal '
                 b'node identifiers'
             )
 
     if opts.get(b'delete'):
         indices = []
         for v in opts.get(b'delete'):
             try:
                 indices.append(int(v))
             except ValueError:
                 raise error.InputError(
                     _(b'invalid index value: %r') % v,
                     hint=_(b'use integers for indices'),
                 )
 
         if repo.currenttransaction():
             raise error.Abort(
                 _(b'cannot delete obsmarkers in the middle of transaction.')
             )
 
         with repo.lock():
             n = repair.deleteobsmarkers(repo.obsstore, indices)
             ui.write(_(b'deleted %i obsolescence markers\n') % n)
 
         return
 
     if precursor is not None:
         if opts[b'rev']:
             raise error.InputError(
                 b'cannot select revision when creating marker'
             )
         metadata = {}
         metadata[b'user'] = encoding.fromlocal(opts[b'user'] or ui.username())
         succs = tuple(parsenodeid(succ) for succ in successors)
         l = repo.lock()
         try:
             tr = repo.transaction(b'debugobsolete')
             try:
                 date = opts.get(b'date')
                 if date:
                     date = dateutil.parsedate(date)
                 else:
                     date = None
                 prec = parsenodeid(precursor)
                 parents = None
                 if opts[b'record_parents']:
                     if prec not in repo.unfiltered():
                         raise error.Abort(
                             b'cannot used --record-parents on '
                             b'unknown changesets'
                         )
                     parents = repo.unfiltered()[prec].parents()
                     parents = tuple(p.node() for p in parents)
                 repo.obsstore.create(
                     tr,
                     prec,
                     succs,
                     opts[b'flags'],
                     parents=parents,
                     date=date,
                     metadata=metadata,
                     ui=ui,
                 )
                 tr.close()
             except ValueError as exc:
                 raise error.Abort(
                     _(b'bad obsmarker input: %s') % stringutil.forcebytestr(exc)
                 )
             finally:
                 tr.release()
         finally:
             l.release()
     else:
         if opts[b'rev']:
             revs = logcmdutil.revrange(repo, opts[b'rev'])
             nodes = [repo[r].node() for r in revs]
             markers = list(
                 obsutil.getmarkers(
                     repo, nodes=nodes, exclusive=opts[b'exclusive']
                 )
             )
             markers.sort(key=lambda x: x._data)
         else:
             markers = obsutil.getmarkers(repo)
 
         markerstoiter = markers
         isrelevant = lambda m: True
         if opts.get(b'rev') and opts.get(b'index'):
             markerstoiter = obsutil.getmarkers(repo)
             markerset = set(markers)
             isrelevant = lambda m: m in markerset
 
         fm = ui.formatter(b'debugobsolete', opts)
         for i, m in enumerate(markerstoiter):
             if not isrelevant(m):
                 # marker can be irrelevant when we're iterating over a set
                 # of markers (markerstoiter) which is bigger than the set
                 # of markers we want to display (markers)
                 # this can happen if both --index and --rev options are
                 # provided and thus we need to iterate over all of the markers
                 # to get the correct indices, but only display the ones that
                 # are relevant to --rev value
                 continue
             fm.startitem()
             ind = i if opts.get(b'index') else None
             cmdutil.showmarker(fm, m, index=ind)
         fm.end()
 
 
 @command(
     b'debugp1copies',
     [(b'r', b'rev', b'', _(b'revision to debug'), _(b'REV'))],
     _(b'[-r REV]'),
 )
 def debugp1copies(ui, repo, **opts):
     """dump copy information compared to p1"""
 
     opts = pycompat.byteskwargs(opts)
     ctx = scmutil.revsingle(repo, opts.get(b'rev'), default=None)
     for dst, src in ctx.p1copies().items():
         ui.write(b'%s -> %s\n' % (src, dst))
 
 
 @command(
     b'debugp2copies',
     [(b'r', b'rev', b'', _(b'revision to debug'), _(b'REV'))],
     _(b'[-r REV]'),
 )
 def debugp2copies(ui, repo, **opts):
     """dump copy information compared to p2"""
 
     opts = pycompat.byteskwargs(opts)
     ctx = scmutil.revsingle(repo, opts.get(b'rev'), default=None)
     for dst, src in ctx.p2copies().items():
         ui.write(b'%s -> %s\n' % (src, dst))
 
 
 @command(
     b'debugpathcomplete',
     [
         (b'f', b'full', None, _(b'complete an entire path')),
         (b'n', b'normal', None, _(b'show only normal files')),
         (b'a', b'added', None, _(b'show only added files')),
         (b'r', b'removed', None, _(b'show only removed files')),
     ],
     _(b'FILESPEC...'),
 )
 def debugpathcomplete(ui, repo, *specs, **opts):
     """complete part or all of a tracked path
 
     This command supports shells that offer path name completion. It
     currently completes only files already known to the dirstate.
 
     Completion extends only to the next path segment unless
     --full is specified, in which case entire paths are used."""
 
     def complete(path, acceptable):
         dirstate = repo.dirstate
         spec = os.path.normpath(os.path.join(encoding.getcwd(), path))
         rootdir = repo.root + pycompat.ossep
         if spec != repo.root and not spec.startswith(rootdir):
             return [], []
         if os.path.isdir(spec):
             spec += b'/'
         spec = spec[len(rootdir) :]
         fixpaths = pycompat.ossep != b'/'
         if fixpaths:
             spec = spec.replace(pycompat.ossep, b'/')
         speclen = len(spec)
         fullpaths = opts['full']
         files, dirs = set(), set()
         adddir, addfile = dirs.add, files.add
         for f, st in dirstate.items():
             if f.startswith(spec) and st.state in acceptable:
                 if fixpaths:
                     f = f.replace(b'/', pycompat.ossep)
                 if fullpaths:
                     addfile(f)
                     continue
                 s = f.find(pycompat.ossep, speclen)
                 if s >= 0:
                     adddir(f[:s])
                 else:
                     addfile(f)
         return files, dirs
 
     acceptable = b''
     if opts['normal']:
         acceptable += b'nm'
     if opts['added']:
         acceptable += b'a'
     if opts['removed']:
         acceptable += b'r'
     cwd = repo.getcwd()
     if not specs:
         specs = [b'.']
 
     files, dirs = set(), set()
     for spec in specs:
         f, d = complete(spec, acceptable or b'nmar')
         files.update(f)
         dirs.update(d)
     files.update(dirs)
     ui.write(b'\n'.join(repo.pathto(p, cwd) for p in sorted(files)))
     ui.write(b'\n')
 
 
 @command(
     b'debugpathcopies',
     cmdutil.walkopts,
     b'hg debugpathcopies REV1 REV2 [FILE]',
     inferrepo=True,
 )
 def debugpathcopies(ui, repo, rev1, rev2, *pats, **opts):
     """show copies between two revisions"""
     ctx1 = scmutil.revsingle(repo, rev1)
     ctx2 = scmutil.revsingle(repo, rev2)
     m = scmutil.match(ctx1, pats, opts)
     for dst, src in sorted(copies.pathcopies(ctx1, ctx2, m).items()):
         ui.write(b'%s -> %s\n' % (src, dst))
 
 
 @command(b'debugpeer', [], _(b'PATH'), norepo=True)
 def debugpeer(ui, path):
     """establish a connection to a peer repository"""
     # Always enable peer request logging. Requires --debug to display
     # though.
     overrides = {
         (b'devel', b'debug.peer-request'): True,
     }
 
     with ui.configoverride(overrides):
         peer = hg.peer(ui, {}, path)
 
         try:
             local = peer.local() is not None
             canpush = peer.canpush()
 
             ui.write(_(b'url: %s\n') % peer.url())
             ui.write(_(b'local: %s\n') % (_(b'yes') if local else _(b'no')))
             ui.write(
                 _(b'pushable: %s\n') % (_(b'yes') if canpush else _(b'no'))
             )
         finally:
             peer.close()
 
 
 @command(
     b'debugpickmergetool',
     [
         (b'r', b'rev', b'', _(b'check for files in this revision'), _(b'REV')),
         (b'', b'changedelete', None, _(b'emulate merging change and delete')),
     ]
     + cmdutil.walkopts
     + cmdutil.mergetoolopts,
     _(b'[PATTERN]...'),
     inferrepo=True,
 )
 def debugpickmergetool(ui, repo, *pats, **opts):
     """examine which merge tool is chosen for specified file
 
     As described in :hg:`help merge-tools`, Mercurial examines
     configurations below in this order to decide which merge tool is
     chosen for specified file.
 
     1. ``--tool`` option
     2. ``HGMERGE`` environment variable
     3. configurations in ``merge-patterns`` section
     4. configuration of ``ui.merge``
     5. configurations in ``merge-tools`` section
     6. ``hgmerge`` tool (for historical reason only)
     7. default tool for fallback (``:merge`` or ``:prompt``)
 
     This command writes out examination result in the style below::
 
         FILE = MERGETOOL
 
     By default, all files known in the first parent context of the
     working directory are examined. Use file patterns and/or -I/-X
     options to limit target files. -r/--rev is also useful to examine
     files in another context without actual updating to it.
 
     With --debug, this command shows warning messages while matching
     against ``merge-patterns`` and so on, too. It is recommended to
     use this option with explicit file patterns and/or -I/-X options,
     because this option increases amount of output per file according
     to configurations in hgrc.
 
     With -v/--verbose, this command shows configurations below at
     first (only if specified).
 
     - ``--tool`` option
     - ``HGMERGE`` environment variable
     - configuration of ``ui.merge``
 
     If merge tool is chosen before matching against
     ``merge-patterns``, this command can't show any helpful
     information, even with --debug. In such case, information above is
     useful to know why a merge tool is chosen.
     """
     opts = pycompat.byteskwargs(opts)
     overrides = {}
     if opts[b'tool']:
         overrides[(b'ui', b'forcemerge')] = opts[b'tool']
         ui.notenoi18n(b'with --tool %r\n' % (pycompat.bytestr(opts[b'tool'])))
 
     with ui.configoverride(overrides, b'debugmergepatterns'):
         hgmerge = encoding.environ.get(b"HGMERGE")
         if hgmerge is not None:
             ui.notenoi18n(b'with HGMERGE=%r\n' % (pycompat.bytestr(hgmerge)))
         uimerge = ui.config(b"ui", b"merge")
         if uimerge:
             ui.notenoi18n(b'with ui.merge=%r\n' % (pycompat.bytestr(uimerge)))
 
         ctx = scmutil.revsingle(repo, opts.get(b'rev'))
         m = scmutil.match(ctx, pats, opts)
         changedelete = opts[b'changedelete']
         for path in ctx.walk(m):
             fctx = ctx[path]
             with ui.silent(
                 error=True
             ) if not ui.debugflag else util.nullcontextmanager():
                 tool, toolpath = filemerge._picktool(
                     repo,
                     ui,
                     path,
                     fctx.isbinary(),
                     b'l' in fctx.flags(),
                     changedelete,
                 )
             ui.write(b'%s = %s\n' % (path, tool))
 
 
 @command(b'debugpushkey', [], _(b'REPO NAMESPACE [KEY OLD NEW]'), norepo=True)
 def debugpushkey(ui, repopath, namespace, *keyinfo, **opts):
     """access the pushkey key/value protocol
 
     With two args, list the keys in the given namespace.
 
     With five args, set a key to new if it currently is set to old.
     Reports success or failure.
     """
 
     target = hg.peer(ui, {}, repopath)
     try:
         if keyinfo:
             key, old, new = keyinfo
             with target.commandexecutor() as e:
                 r = e.callcommand(
                     b'pushkey',
                     {
                         b'namespace': namespace,
                         b'key': key,
                         b'old': old,
                         b'new': new,
                     },
                 ).result()
 
             ui.status(pycompat.bytestr(r) + b'\n')
             return not r
         else:
             for k, v in sorted(target.listkeys(namespace).items()):
                 ui.write(
                     b"%s\t%s\n"
                     % (stringutil.escapestr(k), stringutil.escapestr(v))
                 )
     finally:
         target.close()
 
 
 @command(b'debugpvec', [], _(b'A B'))
 def debugpvec(ui, repo, a, b=None):
     ca = scmutil.revsingle(repo, a)
     cb = scmutil.revsingle(repo, b)
     pa = pvec.ctxpvec(ca)
     pb = pvec.ctxpvec(cb)
     if pa == pb:
         rel = b"="
     elif pa > pb:
         rel = b">"
     elif pa < pb:
         rel = b"<"
     elif pa | pb:
         rel = b"|"
     ui.write(_(b"a: %s\n") % pa)
     ui.write(_(b"b: %s\n") % pb)
     ui.write(_(b"depth(a): %d depth(b): %d\n") % (pa._depth, pb._depth))
     ui.write(
         _(b"delta: %d hdist: %d distance: %d relation: %s\n")
         % (
             abs(pa._depth - pb._depth),
             pvec._hamming(pa._vec, pb._vec),
             pa.distance(pb),
             rel,
         )
     )
 
 
 @command(
     b'debugrebuilddirstate|debugrebuildstate',
     [
         (b'r', b'rev', b'', _(b'revision to rebuild to'), _(b'REV')),
         (
             b'',
             b'minimal',
             None,
             _(
                 b'only rebuild files that are inconsistent with '
                 b'the working copy parent'
             ),
         ),
     ],
     _(b'[-r REV]'),
 )
 def debugrebuilddirstate(ui, repo, rev, **opts):
     """rebuild the dirstate as it would look like for the given revision
 
     If no revision is specified the first current parent will be used.
 
     The dirstate will be set to the files of the given revision.
     The actual working directory content or existing dirstate
     information such as adds or removes is not considered.
 
     ``minimal`` will only rebuild the dirstate status for files that claim to be
     tracked but are not in the parent manifest, or that exist in the parent
     manifest but are not in the dirstate. It will not change adds, removes, or
     modified files that are in the working copy parent.
 
     One use of this command is to make the next :hg:`status` invocation
     check the actual file content.
     """
     ctx = scmutil.revsingle(repo, rev)
     with repo.wlock():
         if repo.currenttransaction() is not None:
             msg = b'rebuild the dirstate outside of a transaction'
             raise error.ProgrammingError(msg)
         dirstate = repo.dirstate
         changedfiles = None
         # See command doc for what minimal does.
         if opts.get('minimal'):
             manifestfiles = set(ctx.manifest().keys())
             dirstatefiles = set(dirstate)
             manifestonly = manifestfiles - dirstatefiles
             dsonly = dirstatefiles - manifestfiles
             dsnotadded = {f for f in dsonly if not dirstate.get_entry(f).added}
             changedfiles = manifestonly | dsnotadded
 
         with dirstate.changing_parents(repo):
             dirstate.rebuild(ctx.node(), ctx.manifest(), changedfiles)
 
 
 @command(
     b'debugrebuildfncache',
     [
         (
             b'',
             b'only-data',
             False,
             _(b'only look for wrong .d files (much faster)'),
         )
     ],
     b'',
 )
 def debugrebuildfncache(ui, repo, **opts):
     """rebuild the fncache file"""
     opts = pycompat.byteskwargs(opts)
     repair.rebuildfncache(ui, repo, opts.get(b"only_data"))
 
 
 @command(
     b'debugrename',
     [(b'r', b'rev', b'', _(b'revision to debug'), _(b'REV'))],
     _(b'[-r REV] [FILE]...'),
 )
 def debugrename(ui, repo, *pats, **opts):
     """dump rename information"""
 
     opts = pycompat.byteskwargs(opts)
     ctx = scmutil.revsingle(repo, opts.get(b'rev'))
     m = scmutil.match(ctx, pats, opts)
     for abs in ctx.walk(m):
         fctx = ctx[abs]
         o = fctx.filelog().renamed(fctx.filenode())
         rel = repo.pathto(abs)
         if o:
             ui.write(_(b"%s renamed from %s:%s\n") % (rel, o[0], hex(o[1])))
         else:
             ui.write(_(b"%s not renamed\n") % rel)
 
 
 @command(b'debugrequires|debugrequirements', [], b'')
 def debugrequirements(ui, repo):
     """print the current repo requirements"""
     for r in sorted(repo.requirements):
         ui.write(b"%s\n" % r)
 
 
 @command(
     b'debugrevlog',
     cmdutil.debugrevlogopts + [(b'd', b'dump', False, _(b'dump index data'))],
     _(b'-c|-m|FILE'),
     optionalrepo=True,
 )
 def debugrevlog(ui, repo, file_=None, **opts):
     """show data and statistics about a revlog"""
     opts = pycompat.byteskwargs(opts)
     r = cmdutil.openrevlog(repo, b'debugrevlog', file_, opts)
 
     if opts.get(b"dump"):
         revlog_debug.dump(ui, r)
     else:
         revlog_debug.debug_revlog(ui, r)
     return 0
 
 
 @command(
     b'debugrevlogindex',
     cmdutil.debugrevlogopts
     + [(b'f', b'format', 0, _(b'revlog format'), _(b'FORMAT'))],
     _(b'[-f FORMAT] -c|-m|FILE'),
     optionalrepo=True,
 )
 def debugrevlogindex(ui, repo, file_=None, **opts):
     """dump the contents of a revlog index"""
     opts = pycompat.byteskwargs(opts)
     r = cmdutil.openrevlog(repo, b'debugrevlogindex', file_, opts)
     format = opts.get(b'format', 0)
     if format not in (0, 1):
         raise error.Abort(_(b"unknown format %d") % format)
 
     if ui.debugflag:
         shortfn = hex
     else:
         shortfn = short
 
     # There might not be anything in r, so have a sane default
     idlen = 12
     for i in r:
         idlen = len(shortfn(r.node(i)))
         break
 
     if format == 0:
         if ui.verbose:
             ui.writenoi18n(
                 b"   rev    offset  length linkrev %s %s p2\n"
                 % (b"nodeid".ljust(idlen), b"p1".ljust(idlen))
             )
         else:
             ui.writenoi18n(
                 b"   rev linkrev %s %s p2\n"
                 % (b"nodeid".ljust(idlen), b"p1".ljust(idlen))
             )
     elif format == 1:
         if ui.verbose:
             ui.writenoi18n(
                 (
                     b"   rev flag   offset   length     size   link     p1"
                     b"     p2 %s\n"
                 )
                 % b"nodeid".rjust(idlen)
             )
         else:
             ui.writenoi18n(
                 b"   rev flag     size   link     p1     p2 %s\n"
                 % b"nodeid".rjust(idlen)
             )
 
     for i in r:
         node = r.node(i)
         if format == 0:
             try:
                 pp = r.parents(node)
             except Exception:
                 pp = [repo.nullid, repo.nullid]
             if ui.verbose:
                 ui.write(
                     b"% 6d % 9d % 7d % 7d %s %s %s\n"
                     % (
                         i,
                         r.start(i),
                         r.length(i),
                         r.linkrev(i),
                         shortfn(node),
                         shortfn(pp[0]),
                         shortfn(pp[1]),
                     )
                 )
             else:
                 ui.write(
                     b"% 6d % 7d %s %s %s\n"
                     % (
                         i,
                         r.linkrev(i),
                         shortfn(node),
                         shortfn(pp[0]),
                         shortfn(pp[1]),
                     )
                 )
         elif format == 1:
             pr = r.parentrevs(i)
             if ui.verbose:
                 ui.write(
                     b"% 6d %04x % 8d % 8d % 8d % 6d % 6d % 6d %s\n"
                     % (
                         i,
                         r.flags(i),
                         r.start(i),
                         r.length(i),
                         r.rawsize(i),
                         r.linkrev(i),
                         pr[0],
                         pr[1],
                         shortfn(node),
                     )
                 )
             else:
                 ui.write(
                     b"% 6d %04x % 8d % 6d % 6d % 6d %s\n"
                     % (
                         i,
                         r.flags(i),
                         r.rawsize(i),
                         r.linkrev(i),
                         pr[0],
                         pr[1],
                         shortfn(node),
                     )
                 )
 
 
 @command(
     b'debugrevspec',
     [
         (
             b'',
             b'optimize',
             None,
             _(b'print parsed tree after optimizing (DEPRECATED)'),
         ),
         (
             b'',
             b'show-revs',
             True,
             _(b'print list of result revisions (default)'),
         ),
         (
             b's',
             b'show-set',
             None,
             _(b'print internal representation of result set'),
         ),
         (
             b'p',
             b'show-stage',
             [],
             _(b'print parsed tree at the given stage'),
             _(b'NAME'),
         ),
         (b'', b'no-optimized', False, _(b'evaluate tree without optimization')),
         (b'', b'verify-optimized', False, _(b'verify optimized result')),
     ],
     b'REVSPEC',
 )
 def debugrevspec(ui, repo, expr, **opts):
     """parse and apply a revision specification
 
     Use -p/--show-stage option to print the parsed tree at the given stages.
     Use -p all to print tree at every stage.
 
     Use --no-show-revs option with -s or -p to print only the set
     representation or the parsed tree respectively.
 
     Use --verify-optimized to compare the optimized result with the unoptimized
     one. Returns 1 if the optimized result differs.
     """
     opts = pycompat.byteskwargs(opts)
     aliases = ui.configitems(b'revsetalias')
     stages = [
         (b'parsed', lambda tree: tree),
         (
             b'expanded',
             lambda tree: revsetlang.expandaliases(tree, aliases, ui.warn),
         ),
         (b'concatenated', revsetlang.foldconcat),
         (b'analyzed', revsetlang.analyze),
         (b'optimized', revsetlang.optimize),
     ]
     if opts[b'no_optimized']:
         stages = stages[:-1]
     if opts[b'verify_optimized'] and opts[b'no_optimized']:
         raise error.Abort(
             _(b'cannot use --verify-optimized with --no-optimized')
         )
     stagenames = {n for n, f in stages}
 
     showalways = set()
     showchanged = set()
     if ui.verbose and not opts[b'show_stage']:
         # show parsed tree by --verbose (deprecated)
         showalways.add(b'parsed')
         showchanged.update([b'expanded', b'concatenated'])
         if opts[b'optimize']:
             showalways.add(b'optimized')
     if opts[b'show_stage'] and opts[b'optimize']:
         raise error.Abort(_(b'cannot use --optimize with --show-stage'))
     if opts[b'show_stage'] == [b'all']:
         showalways.update(stagenames)
     else:
         for n in opts[b'show_stage']:
             if n not in stagenames:
                 raise error.Abort(_(b'invalid stage name: %s') % n)
         showalways.update(opts[b'show_stage'])
 
     treebystage = {}
     printedtree = None
     tree = revsetlang.parse(expr, lookup=revset.lookupfn(repo))
     for n, f in stages:
         treebystage[n] = tree = f(tree)
         if n in showalways or (n in showchanged and tree != printedtree):
             if opts[b'show_stage'] or n != b'parsed':
                 ui.write(b"* %s:\n" % n)
             ui.write(revsetlang.prettyformat(tree), b"\n")
             printedtree = tree
 
     if opts[b'verify_optimized']:
         arevs = revset.makematcher(treebystage[b'analyzed'])(repo)
         brevs = revset.makematcher(treebystage[b'optimized'])(repo)
         if opts[b'show_set'] or (opts[b'show_set'] is None and ui.verbose):
             ui.writenoi18n(
                 b"* analyzed set:\n", stringutil.prettyrepr(arevs), b"\n"
             )
             ui.writenoi18n(
                 b"* optimized set:\n", stringutil.prettyrepr(brevs), b"\n"
             )
         arevs = list(arevs)
         brevs = list(brevs)
         if arevs == brevs:
             return 0
         ui.writenoi18n(b'--- analyzed\n', label=b'diff.file_a')
         ui.writenoi18n(b'+++ optimized\n', label=b'diff.file_b')
         sm = difflib.SequenceMatcher(None, arevs, brevs)
         for tag, alo, ahi, blo, bhi in sm.get_opcodes():
             if tag in ('delete', 'replace'):
                 for c in arevs[alo:ahi]:
                     ui.write(b'-%d\n' % c, label=b'diff.deleted')
             if tag in ('insert', 'replace'):
                 for c in brevs[blo:bhi]:
                     ui.write(b'+%d\n' % c, label=b'diff.inserted')
             if tag == 'equal':
                 for c in arevs[alo:ahi]:
                     ui.write(b' %d\n' % c)
         return 1
 
     func = revset.makematcher(tree)
     revs = func(repo)
     if opts[b'show_set'] or (opts[b'show_set'] is None and ui.verbose):
         ui.writenoi18n(b"* set:\n", stringutil.prettyrepr(revs), b"\n")
     if not opts[b'show_revs']:
         return
     for c in revs:
         ui.write(b"%d\n" % c)
 
 
 @command(
     b'debugserve',
     [
         (
             b'',
             b'sshstdio',
             False,
             _(b'run an SSH server bound to process handles'),
         ),
         (b'', b'logiofd', b'', _(b'file descriptor to log server I/O to')),
         (b'', b'logiofile', b'', _(b'file to log server I/O to')),
     ],
     b'',
 )
 def debugserve(ui, repo, **opts):
     """run a server with advanced settings
 
     This command is similar to :hg:`serve`. It exists partially as a
     workaround to the fact that ``hg serve --stdio`` must have specific
     arguments for security reasons.
     """
     opts = pycompat.byteskwargs(opts)
 
     if not opts[b'sshstdio']:
         raise error.Abort(_(b'only --sshstdio is currently supported'))
 
     logfh = None
 
     if opts[b'logiofd'] and opts[b'logiofile']:
         raise error.Abort(_(b'cannot use both --logiofd and --logiofile'))
 
     if opts[b'logiofd']:
         # Ideally we would be line buffered. But line buffering in binary
         # mode isn't supported and emits a warning in Python 3.8+. Disabling
         # buffering could have performance impacts. But since this isn't
         # performance critical code, it should be fine.
         try:
             logfh = os.fdopen(int(opts[b'logiofd']), 'ab', 0)
         except OSError as e:
             if e.errno != errno.ESPIPE:
                 raise
             # can't seek a pipe, so `ab` mode fails on py3
             logfh = os.fdopen(int(opts[b'logiofd']), 'wb', 0)
     elif opts[b'logiofile']:
         logfh = open(opts[b'logiofile'], b'ab', 0)
 
     s = wireprotoserver.sshserver(ui, repo, logfh=logfh)
     s.serve_forever()
 
 
 @command(b'debugsetparents', [], _(b'REV1 [REV2]'))
 def debugsetparents(ui, repo, rev1, rev2=None):
     """manually set the parents of the current working directory (DANGEROUS)
 
     This command is not what you are looking for and should not be used. Using
     this command will most certainly results in slight corruption of the file
     level histories withing your repository. DO NOT USE THIS COMMAND.
 
     The command update the p1 and p2 field in the dirstate, and not touching
     anything else. This useful for writing repository conversion tools, but
     should be used with extreme care. For example, neither the working
     directory nor the dirstate is updated, so file status may be incorrect
     after running this command. Only used if you are one of the few people that
     deeply unstand both conversion tools and file level histories. If you are
     reading this help, you are not one of this people (most of them sailed west
     from Mithlond anyway.
 
     So one last time DO NOT USE THIS COMMAND.
 
     Returns 0 on success.
     """
 
     node1 = scmutil.revsingle(repo, rev1).node()
     node2 = scmutil.revsingle(repo, rev2, b'null').node()
 
     with repo.wlock():
         repo.setparents(node1, node2)
 
 
 @command(b'debugsidedata', cmdutil.debugrevlogopts, _(b'-c|-m|FILE REV'))
 def debugsidedata(ui, repo, file_, rev=None, **opts):
     """dump the side data for a cl/manifest/file revision
 
     Use --verbose to dump the sidedata content."""
     opts = pycompat.byteskwargs(opts)
     if opts.get(b'changelog') or opts.get(b'manifest') or opts.get(b'dir'):
         if rev is not None:
             raise error.CommandError(b'debugdata', _(b'invalid arguments'))
         file_, rev = None, file_
     elif rev is None:
         raise error.CommandError(b'debugdata', _(b'invalid arguments'))
     r = cmdutil.openstorage(repo, b'debugdata', file_, opts)
     r = getattr(r, '_revlog', r)
     try:
         sidedata = r.sidedata(r.lookup(rev))
     except KeyError:
         raise error.Abort(_(b'invalid revision identifier %s') % rev)
     if sidedata:
         sidedata = list(sidedata.items())
         sidedata.sort()
         ui.writenoi18n(b'%d sidedata entries\n' % len(sidedata))
         for key, value in sidedata:
             ui.writenoi18n(b' entry-%04o size %d\n' % (key, len(value)))
             if ui.verbose:
                 ui.writenoi18n(b'  %s\n' % stringutil.pprint(value))
 
 
 @command(b'debugssl', [], b'[SOURCE]', optionalrepo=True)
 def debugssl(ui, repo, source=None, **opts):
     """test a secure connection to a server
 
     This builds the certificate chain for the server on Windows, installing the
     missing intermediates and trusted root via Windows Update if necessary.  It
     does nothing on other platforms.
 
     If SOURCE is omitted, the 'default' path will be used.  If a URL is given,
     that server is used. See :hg:`help urls` for more information.
 
     If the update succeeds, retry the original operation.  Otherwise, the cause
     of the SSL error is likely another issue.
     """
     if not pycompat.iswindows:
         raise error.Abort(
             _(b'certificate chain building is only possible on Windows')
         )
 
     if not source:
         if not repo:
             raise error.Abort(
                 _(
                     b"there is no Mercurial repository here, and no "
                     b"server specified"
                 )
             )
         source = b"default"
 
     path = urlutil.get_unique_pull_path_obj(b'debugssl', ui, source)
     url = path.url
 
     defaultport = {b'https': 443, b'ssh': 22}
     if url.scheme in defaultport:
         try:
             addr = (url.host, int(url.port or defaultport[url.scheme]))
         except ValueError:
             raise error.Abort(_(b"malformed port number in URL"))
     else:
         raise error.Abort(_(b"only https and ssh connections are supported"))
 
     from . import win32
 
     s = ssl.wrap_socket(
         socket.socket(),
         ssl_version=ssl.PROTOCOL_TLS,
         cert_reqs=ssl.CERT_NONE,
         ca_certs=None,
     )
 
     try:
         s.connect(addr)
         cert = s.getpeercert(True)
 
         ui.status(_(b'checking the certificate chain for %s\n') % url.host)
 
         complete = win32.checkcertificatechain(cert, build=False)
 
         if not complete:
             ui.status(_(b'certificate chain is incomplete, updating... '))
 
             if not win32.checkcertificatechain(cert):
                 ui.status(_(b'failed.\n'))
             else:
                 ui.status(_(b'done.\n'))
         else:
             ui.status(_(b'full certificate chain is available\n'))
     finally:
         s.close()
 
 
 @command(
     b"debugbackupbundle",
     [
         (
             b"",
             b"recover",
             b"",
             b"brings the specified changeset back into the repository",
         )
     ]
     + cmdutil.logopts,
     _(b"hg debugbackupbundle [--recover HASH]"),
 )
 def debugbackupbundle(ui, repo, *pats, **opts):
     """lists the changesets available in backup bundles
 
     Without any arguments, this command prints a list of the changesets in each
     backup bundle.
 
     --recover takes a changeset hash and unbundles the first bundle that
     contains that hash, which puts that changeset back in your repository.
 
     --verbose will print the entire commit message and the bundle path for that
     backup.
     """
     backups = list(
         filter(
             os.path.isfile, glob.glob(repo.vfs.join(b"strip-backup") + b"/*.hg")
         )
     )
     backups.sort(key=lambda x: os.path.getmtime(x), reverse=True)
 
     opts = pycompat.byteskwargs(opts)
     opts[b"bundle"] = b""
     opts[b"force"] = None
     limit = logcmdutil.getlimit(opts)
 
     def display(other, chlist, displayer):
         if opts.get(b"newest_first"):
             chlist.reverse()
         count = 0
         for n in chlist:
             if limit is not None and count >= limit:
                 break
             parents = [
                 True for p in other.changelog.parents(n) if p != repo.nullid
             ]
             if opts.get(b"no_merges") and len(parents) == 2:
                 continue
             count += 1
             displayer.show(other[n])
 
     recovernode = opts.get(b"recover")
     if recovernode:
         if scmutil.isrevsymbol(repo, recovernode):
             ui.warn(_(b"%s already exists in the repo\n") % recovernode)
             return
     elif backups:
         msg = _(
             b"Recover changesets using: hg debugbackupbundle --recover "
             b"<changeset hash>\n\nAvailable backup changesets:"
         )
         ui.status(msg, label=b"status.removed")
     else:
         ui.status(_(b"no backup changesets found\n"))
         return
 
     for backup in backups:
         # Much of this is copied from the hg incoming logic
         source = os.path.relpath(backup, encoding.getcwd())
         path = urlutil.get_unique_pull_path_obj(
             b'debugbackupbundle',
             ui,
             source,
         )
         try:
             other = hg.peer(repo, opts, path)
         except error.LookupError as ex:
             msg = _(b"\nwarning: unable to open bundle %s") % path.loc
             hint = _(b"\n(missing parent rev %s)\n") % short(ex.name)
             ui.warn(msg, hint=hint)
             continue
         branches = (path.branch, opts.get(b'branch', []))
         revs, checkout = hg.addbranchrevs(
             repo, other, branches, opts.get(b"rev")
         )
 
         if revs:
             revs = [other.lookup(rev) for rev in revs]
 
         with ui.silent():
             try:
                 other, chlist, cleanupfn = bundlerepo.getremotechanges(
                     ui, repo, other, revs, opts[b"bundle"], opts[b"force"]
                 )
             except error.LookupError:
                 continue
 
         try:
             if not chlist:
                 continue
             if recovernode:
                 with repo.lock(), repo.transaction(b"unbundle") as tr:
                     if scmutil.isrevsymbol(other, recovernode):
                         ui.status(_(b"Unbundling %s\n") % (recovernode))
                         f = hg.openpath(ui, path.loc)
                         gen = exchange.readbundle(ui, f, path.loc)
                         if isinstance(gen, bundle2.unbundle20):
                             bundle2.applybundle(
                                 repo,
                                 gen,
                                 tr,
                                 source=b"unbundle",
                                 url=b"bundle:" + path.loc,
                             )
                         else:
                             gen.apply(repo, b"unbundle", b"bundle:" + path.loc)
                         break
             else:
                 backupdate = encoding.strtolocal(
                     time.strftime(
                         "%a %H:%M, %Y-%m-%d",
                         time.localtime(os.path.getmtime(path.loc)),
                     )
                 )
                 ui.status(b"\n%s\n" % (backupdate.ljust(50)))
                 if ui.verbose:
                     ui.status(b"%s%s\n" % (b"bundle:".ljust(13), path.loc))
                 else:
                     opts[
                         b"template"
                     ] = b"{label('status.modified', node|short)} {desc|firstline}\n"
                 displayer = logcmdutil.changesetdisplayer(
                     ui, other, opts, False
                 )
                 display(other, chlist, displayer)
                 displayer.close()
         finally:
             cleanupfn()
 
 
 @command(
     b'debugsub',
     [(b'r', b'rev', b'', _(b'revision to check'), _(b'REV'))],
     _(b'[-r REV] [REV]'),
 )
 def debugsub(ui, repo, rev=None):
     ctx = scmutil.revsingle(repo, rev, None)
     for k, v in sorted(ctx.substate.items()):
         ui.writenoi18n(b'path %s\n' % k)
         ui.writenoi18n(b' source   %s\n' % v[0])
         ui.writenoi18n(b' revision %s\n' % v[1])
 
 
 @command(
     b'debugshell',
     [
         (
             b'c',
             b'command',
             b'',
             _(b'program passed in as a string'),
             _(b'COMMAND'),
         )
     ],
     _(b'[-c COMMAND]'),
     optionalrepo=True,
 )
 def debugshell(ui, repo, **opts):
     """run an interactive Python interpreter
 
     The local namespace is provided with a reference to the ui and
     the repo instance (if available).
     """
     import code
 
     imported_objects = {
         'ui': ui,
         'repo': repo,
     }
 
     # py2exe disables initialization of the site module, which is responsible
     # for arranging for ``quit()`` to exit the interpreter.  Manually initialize
     # the stuff that site normally does here, so that the interpreter can be
     # quit in a consistent manner, whether run with pyoxidizer, exewrapper.c,
     # py.exe, or py2exe.
     if getattr(sys, "frozen", None) == 'console_exe':
         try:
             import site
 
             site.setcopyright()
             site.sethelper()
             site.setquit()
         except ImportError:
             site = None  # Keep PyCharm happy
 
     command = opts.get('command')
     if command:
         compiled = code.compile_command(encoding.strfromlocal(command))
         code.InteractiveInterpreter(locals=imported_objects).runcode(compiled)
         return
 
     code.interact(local=imported_objects)
 
 
 @command(
     b'debug-revlog-stats',
     [
         (b'c', b'changelog', None, _(b'Display changelog statistics')),
         (b'm', b'manifest', None, _(b'Display manifest statistics')),
         (b'f', b'filelogs', None, _(b'Display filelogs statistics')),
     ]
     + cmdutil.formatteropts,
 )
 def debug_revlog_stats(ui, repo, **opts):
     """display statistics about revlogs in the store"""
     opts = pycompat.byteskwargs(opts)
     changelog = opts[b"changelog"]
     manifest = opts[b"manifest"]
     filelogs = opts[b"filelogs"]
 
     if changelog is None and manifest is None and filelogs is None:
         changelog = True
         manifest = True
         filelogs = True
 
     repo = repo.unfiltered()
     fm = ui.formatter(b'debug-revlog-stats', opts)
     revlog_debug.debug_revlog_stats(repo, fm, changelog, manifest, filelogs)
     fm.end()
 
 
 @command(
     b'debugsuccessorssets',
     [(b'', b'closest', False, _(b'return closest successors sets only'))],
     _(b'[REV]'),
 )
 def debugsuccessorssets(ui, repo, *revs, **opts):
     """show set of successors for revision
 
     A successors set of changeset A is a consistent group of revisions that
     succeed A. It contains non-obsolete changesets only unless closests
     successors set is set.
 
     In most cases a changeset A has a single successors set containing a single
     successor (changeset A replaced by A').
 
     A changeset that is made obsolete with no successors are called "pruned".
     Such changesets have no successors sets at all.
 
     A changeset that has been "split" will have a successors set containing
     more than one successor.
 
     A changeset that has been rewritten in multiple different ways is called
     "divergent". Such changesets have multiple successor sets (each of which
     may also be split, i.e. have multiple successors).
 
     Results are displayed as follows::
 
         <rev1>
             <successors-1A>
         <rev2>
             <successors-2A>
             <successors-2B1> <successors-2B2> <successors-2B3>
 
     Here rev2 has two possible (i.e. divergent) successors sets. The first
     holds one element, whereas the second holds three (i.e. the changeset has
     been split).
     """
     # passed to successorssets caching computation from one call to another
     cache = {}
     ctx2str = bytes
     node2str = short
     for rev in logcmdutil.revrange(repo, revs):
         ctx = repo[rev]
         ui.write(b'%s\n' % ctx2str(ctx))
         for succsset in obsutil.successorssets(
             repo, ctx.node(), closest=opts['closest'], cache=cache
         ):
             if succsset:
                 ui.write(b'    ')
                 ui.write(node2str(succsset[0]))
                 for node in succsset[1:]:
                     ui.write(b' ')
                     ui.write(node2str(node))
             ui.write(b'\n')
 
 
 @command(b'debugtagscache', [])
 def debugtagscache(ui, repo):
     """display the contents of .hg/cache/hgtagsfnodes1"""
     cache = tagsmod.hgtagsfnodescache(repo.unfiltered())
     flog = repo.file(b'.hgtags')
     for r in repo:
         node = repo[r].node()
         tagsnode = cache.getfnode(node, computemissing=False)
         if tagsnode:
             tagsnodedisplay = hex(tagsnode)
             if not flog.hasnode(tagsnode):
                 tagsnodedisplay += b' (unknown node)'
         elif tagsnode is None:
             tagsnodedisplay = b'missing'
         else:
             tagsnodedisplay = b'invalid'
 
         ui.write(b'%d %s %s\n' % (r, hex(node), tagsnodedisplay))
 
 
 @command(
     b'debugtemplate',
     [
         (b'r', b'rev', [], _(b'apply template on changesets'), _(b'REV')),
         (b'D', b'define', [], _(b'define template keyword'), _(b'KEY=VALUE')),
     ],
     _(b'[-r REV]... [-D KEY=VALUE]... TEMPLATE'),
     optionalrepo=True,
 )
 def debugtemplate(ui, repo, tmpl, **opts):
     """parse and apply a template
 
     If -r/--rev is given, the template is processed as a log template and
     applied to the given changesets. Otherwise, it is processed as a generic
     template.
 
     Use --verbose to print the parsed tree.
     """
     revs = None
     if opts['rev']:
         if repo is None:
             raise error.RepoError(
                 _(b'there is no Mercurial repository here (.hg not found)')
             )
         revs = logcmdutil.revrange(repo, opts['rev'])
 
     props = {}
     for d in opts['define']:
         try:
             k, v = (e.strip() for e in d.split(b'=', 1))
             if not k or k == b'ui':
                 raise ValueError
             props[k] = v
         except ValueError:
             raise error.Abort(_(b'malformed keyword definition: %s') % d)
 
     if ui.verbose:
         aliases = ui.configitems(b'templatealias')
         tree = templater.parse(tmpl)
         ui.note(templater.prettyformat(tree), b'\n')
         newtree = templater.expandaliases(tree, aliases)
         if newtree != tree:
             ui.notenoi18n(
                 b"* expanded:\n", templater.prettyformat(newtree), b'\n'
             )
 
     if revs is None:
         tres = formatter.templateresources(ui, repo)
         t = formatter.maketemplater(ui, tmpl, resources=tres)
         if ui.verbose:
             kwds, funcs = t.symbolsuseddefault()
             ui.writenoi18n(b"* keywords: %s\n" % b', '.join(sorted(kwds)))
             ui.writenoi18n(b"* functions: %s\n" % b', '.join(sorted(funcs)))
         ui.write(t.renderdefault(props))
     else:
         displayer = logcmdutil.maketemplater(ui, repo, tmpl)
         if ui.verbose:
             kwds, funcs = displayer.t.symbolsuseddefault()
             ui.writenoi18n(b"* keywords: %s\n" % b', '.join(sorted(kwds)))
             ui.writenoi18n(b"* functions: %s\n" % b', '.join(sorted(funcs)))
         for r in revs:
             displayer.show(repo[r], **pycompat.strkwargs(props))
         displayer.close()
 
 
 @command(
     b'debuguigetpass',
     [
         (b'p', b'prompt', b'', _(b'prompt text'), _(b'TEXT')),
     ],
     _(b'[-p TEXT]'),
     norepo=True,
 )
 def debuguigetpass(ui, prompt=b''):
     """show prompt to type password"""
     r = ui.getpass(prompt)
     if r is None:
         r = b"<default response>"
     ui.writenoi18n(b'response: %s\n' % r)
 
 
 @command(
     b'debuguiprompt',
     [
         (b'p', b'prompt', b'', _(b'prompt text'), _(b'TEXT')),
     ],
     _(b'[-p TEXT]'),
     norepo=True,
 )
 def debuguiprompt(ui, prompt=b''):
     """show plain prompt"""
     r = ui.prompt(prompt)
     ui.writenoi18n(b'response: %s\n' % r)
 
 
 @command(b'debugupdatecaches', [])
 def debugupdatecaches(ui, repo, *pats, **opts):
     """warm all known caches in the repository"""
     with repo.wlock(), repo.lock():
         repo.updatecaches(caches=repository.CACHES_ALL)
 
 
 @command(
     b'debugupgraderepo',
     [
         (
             b'o',
             b'optimize',
             [],
             _(b'extra optimization to perform'),
             _(b'NAME'),
         ),
         (b'', b'run', False, _(b'performs an upgrade')),
         (b'', b'backup', True, _(b'keep the old repository content around')),
         (b'', b'changelog', None, _(b'select the changelog for upgrade')),
         (b'', b'manifest', None, _(b'select the manifest for upgrade')),
         (b'', b'filelogs', None, _(b'select all filelogs for upgrade')),
     ],
 )
 def debugupgraderepo(ui, repo, run=False, optimize=None, backup=True, **opts):
     """upgrade a repository to use different features
 
     If no arguments are specified, the repository is evaluated for upgrade
     and a list of problems and potential optimizations is printed.
 
     With ``--run``, a repository upgrade is performed. Behavior of the upgrade
     can be influenced via additional arguments. More details will be provided
     by the command output when run without ``--run``.
 
     During the upgrade, the repository will be locked and no writes will be
     allowed.
 
     At the end of the upgrade, the repository may not be readable while new
     repository data is swapped in. This window will be as long as it takes to
     rename some directories inside the ``.hg`` directory. On most machines, this
     should complete almost instantaneously and the chances of a consumer being
     unable to access the repository should be low.
 
     By default, all revlogs will be upgraded. You can restrict this using flags
     such as `--manifest`:
 
       * `--manifest`: only optimize the manifest
       * `--no-manifest`: optimize all revlog but the manifest
       * `--changelog`: optimize the changelog only
       * `--no-changelog --no-manifest`: optimize filelogs only
       * `--filelogs`: optimize the filelogs only
       * `--no-changelog --no-manifest --no-filelogs`: skip all revlog optimizations
     """
     return upgrade.upgraderepo(
         ui, repo, run=run, optimize=set(optimize), backup=backup, **opts
     )
 
 
 @command(
     b'debugwalk', cmdutil.walkopts, _(b'[OPTION]... [FILE]...'), inferrepo=True
 )
 def debugwalk(ui, repo, *pats, **opts):
     """show how files match on given patterns"""
     opts = pycompat.byteskwargs(opts)
     m = scmutil.match(repo[None], pats, opts)
     if ui.verbose:
         ui.writenoi18n(b'* matcher:\n', stringutil.prettyrepr(m), b'\n')
     items = list(repo[None].walk(m))
     if not items:
         return
     f = lambda fn: fn
     if ui.configbool(b'ui', b'slash') and pycompat.ossep != b'/':
         f = lambda fn: util.normpath(fn)
     fmt = b'f  %%-%ds  %%-%ds  %%s' % (
         max([len(abs) for abs in items]),
         max([len(repo.pathto(abs)) for abs in items]),
     )
     for abs in items:
         line = fmt % (
             abs,
             f(repo.pathto(abs)),
             m.exact(abs) and b'exact' or b'',
         )
         ui.write(b"%s\n" % line.rstrip())
 
 
 @command(b'debugwhyunstable', [], _(b'REV'))
 def debugwhyunstable(ui, repo, rev):
     """explain instabilities of a changeset"""
     for entry in obsutil.whyunstable(repo, scmutil.revsingle(repo, rev)):
         dnodes = b''
         if entry.get(b'divergentnodes'):
             dnodes = (
                 b' '.join(
                     b'%s (%s)' % (ctx.hex(), ctx.phasestr())
                     for ctx in entry[b'divergentnodes']
                 )
                 + b' '
             )
         ui.write(
             b'%s: %s%s %s\n'
             % (entry[b'instability'], dnodes, entry[b'reason'], entry[b'node'])
         )
 
 
 @command(
     b'debugwireargs',
     [
         (b'', b'three', b'', b'three'),
         (b'', b'four', b'', b'four'),
         (b'', b'five', b'', b'five'),
     ]
     + cmdutil.remoteopts,
     _(b'REPO [OPTIONS]... [ONE [TWO]]'),
     norepo=True,
 )
 def debugwireargs(ui, repopath, *vals, **opts):
     opts = pycompat.byteskwargs(opts)
     repo = hg.peer(ui, opts, repopath)
     try:
         for opt in cmdutil.remoteopts:
             del opts[opt[1]]
         args = {}
         for k, v in opts.items():
             if v:
                 args[k] = v
         args = pycompat.strkwargs(args)
         # run twice to check that we don't mess up the stream for the next command
         res1 = repo.debugwireargs(*vals, **args)
         res2 = repo.debugwireargs(*vals, **args)
         ui.write(b"%s\n" % res1)
         if res1 != res2:
             ui.warn(b"%s\n" % res2)
     finally:
         repo.close()
 
 
 def _parsewirelangblocks(fh):
     activeaction = None
     blocklines = []
     lastindent = 0
 
     for line in fh:
         line = line.rstrip()
         if not line:
             continue
 
         if line.startswith(b'#'):
             continue
 
         if not line.startswith(b' '):
             # New block. Flush previous one.
             if activeaction:
                 yield activeaction, blocklines
 
             activeaction = line
             blocklines = []
             lastindent = 0
             continue
 
         # Else we start with an indent.
 
         if not activeaction:
             raise error.Abort(_(b'indented line outside of block'))
 
         indent = len(line) - len(line.lstrip())
 
         # If this line is indented more than the last line, concatenate it.
         if indent > lastindent and blocklines:
             blocklines[-1] += line.lstrip()
         else:
             blocklines.append(line)
             lastindent = indent
 
     # Flush last block.
     if activeaction:
         yield activeaction, blocklines
 
 
 @command(
     b'debugwireproto',
     [
         (b'', b'localssh', False, _(b'start an SSH server for this repo')),
         (b'', b'peer', b'', _(b'construct a specific version of the peer')),
         (
             b'',
             b'noreadstderr',
             False,
             _(b'do not read from stderr of the remote'),
         ),
         (
             b'',
             b'nologhandshake',
             False,
             _(b'do not log I/O related to the peer handshake'),
         ),
     ]
     + cmdutil.remoteopts,
     _(b'[PATH]'),
     optionalrepo=True,
 )
 def debugwireproto(ui, repo, path=None, **opts):
     """send wire protocol commands to a server
 
     This command can be used to issue wire protocol commands to remote
     peers and to debug the raw data being exchanged.
 
     ``--localssh`` will start an SSH server against the current repository
     and connect to that. By default, the connection will perform a handshake
     and establish an appropriate peer instance.
 
     ``--peer`` can be used to bypass the handshake protocol and construct a
     peer instance using the specified class type. Valid values are ``raw``,
     ``ssh1``. ``raw`` instances only allow sending raw data payloads and
     don't support higher-level command actions.
 
     ``--noreadstderr`` can be used to disable automatic reading from stderr
     of the peer (for SSH connections only). Disabling automatic reading of
     stderr is useful for making output more deterministic.
 
     Commands are issued via a mini language which is specified via stdin.
     The language consists of individual actions to perform. An action is
     defined by a block. A block is defined as a line with no leading
     space followed by 0 or more lines with leading space. Blocks are
     effectively a high-level command with additional metadata.
 
     Lines beginning with ``#`` are ignored.
 
     The following sections denote available actions.
 
     raw
     ---
 
     Send raw data to the server.
 
     The block payload contains the raw data to send as one atomic send
     operation. The data may not actually be delivered in a single system
     call: it depends on the abilities of the transport being used.
 
     Each line in the block is de-indented and concatenated. Then, that
     value is evaluated as a Python b'' literal. This allows the use of
     backslash escaping, etc.
 
     raw+
     ----
 
     Behaves like ``raw`` except flushes output afterwards.
 
     command <X>
     -----------
 
     Send a request to run a named command, whose name follows the ``command``
     string.
 
     Arguments to the command are defined as lines in this block. The format of
     each line is ``<key> <value>``. e.g.::
 
        command listkeys
            namespace bookmarks
 
     If the value begins with ``eval:``, it will be interpreted as a Python
     literal expression. Otherwise values are interpreted as Python b'' literals.
     This allows sending complex types and encoding special byte sequences via
     backslash escaping.
 
     The following arguments have special meaning:
 
     ``PUSHFILE``
         When defined, the *push* mechanism of the peer will be used instead
         of the static request-response mechanism and the content of the
         file specified in the value of this argument will be sent as the
         command payload.
 
         This can be used to submit a local bundle file to the remote.
 
     batchbegin
     ----------
 
     Instruct the peer to begin a batched send.
 
     All ``command`` blocks are queued for execution until the next
     ``batchsubmit`` block.
 
     batchsubmit
     -----------
 
     Submit previously queued ``command`` blocks as a batch request.
 
     This action MUST be paired with a ``batchbegin`` action.
 
     httprequest <method> <path>
     ---------------------------
 
     (HTTP peer only)
 
     Send an HTTP request to the peer.
 
     The HTTP request line follows the ``httprequest`` action. e.g. ``GET /foo``.
 
     Arguments of the form ``<key>: <value>`` are interpreted as HTTP request
     headers to add to the request. e.g. ``Accept: foo``.
 
     The following arguments are special:
 
     ``BODYFILE``
         The content of the file defined as the value to this argument will be
         transferred verbatim as the HTTP request body.
 
     ``frame <type> <flags> <payload>``
         Send a unified protocol frame as part of the request body.
 
         All frames will be collected and sent as the body to the HTTP
         request.
 
     close
     -----
 
     Close the connection to the server.
 
     flush
     -----
 
     Flush data written to the server.
 
     readavailable
     -------------
 
     Close the write end of the connection and read all available data from
     the server.
 
     If the connection to the server encompasses multiple pipes, we poll both
     pipes and read available data.
 
     readline
     --------
 
     Read a line of output from the server. If there are multiple output
     pipes, reads only the main pipe.
 
     ereadline
     ---------
 
     Like ``readline``, but read from the stderr pipe, if available.
 
     read <X>
     --------
 
     ``read()`` N bytes from the server's main output pipe.
 
     eread <X>
     ---------
 
     ``read()`` N bytes from the server's stderr pipe, if available.
 
     Specifying Unified Frame-Based Protocol Frames
     ----------------------------------------------
 
     It is possible to emit a *Unified Frame-Based Protocol* by using special
     syntax.
 
     A frame is composed as a type, flags, and payload. These can be parsed
     from a string of the form:
 
        <request-id> <stream-id> <stream-flags> <type> <flags> <payload>
 
     ``request-id`` and ``stream-id`` are integers defining the request and
     stream identifiers.
 
     ``type`` can be an integer value for the frame type or the string name
     of the type. The strings are defined in ``wireprotoframing.py``. e.g.
     ``command-name``.
 
     ``stream-flags`` and ``flags`` are a ``|`` delimited list of flag
     components. Each component (and there can be just one) can be an integer
     or a flag name for stream flags or frame flags, respectively. Values are
     resolved to integers and then bitwise OR'd together.
 
     ``payload`` represents the raw frame payload. If it begins with
     ``cbor:``, the following string is evaluated as Python code and the
     resulting object is fed into a CBOR encoder. Otherwise it is interpreted
     as a Python byte string literal.
     """
     opts = pycompat.byteskwargs(opts)
 
     if opts[b'localssh'] and not repo:
         raise error.Abort(_(b'--localssh requires a repository'))
 
     if opts[b'peer'] and opts[b'peer'] not in (
         b'raw',
         b'ssh1',
     ):
         raise error.Abort(
             _(b'invalid value for --peer'),
             hint=_(b'valid values are "raw" and "ssh1"'),
         )
 
     if path and opts[b'localssh']:
         raise error.Abort(_(b'cannot specify --localssh with an explicit path'))
 
     if ui.interactive():
         ui.write(_(b'(waiting for commands on stdin)\n'))
 
     blocks = list(_parsewirelangblocks(ui.fin))
 
     proc = None
     stdin = None
     stdout = None
     stderr = None
     opener = None
 
     if opts[b'localssh']:
         # We start the SSH server in its own process so there is process
         # separation. This prevents a whole class of potential bugs around
         # shared state from interfering with server operation.
         args = procutil.hgcmd() + [
             b'-R',
             repo.root,
             b'debugserve',
             b'--sshstdio',
         ]
         proc = subprocess.Popen(
             pycompat.rapply(procutil.tonativestr, args),
             stdin=subprocess.PIPE,
             stdout=subprocess.PIPE,
             stderr=subprocess.PIPE,
             bufsize=0,
         )
 
         stdin = proc.stdin
         stdout = proc.stdout
         stderr = proc.stderr
 
         # We turn the pipes into observers so we can log I/O.
         if ui.verbose or opts[b'peer'] == b'raw':
             stdin = util.makeloggingfileobject(
                 ui, proc.stdin, b'i', logdata=True
             )
             stdout = util.makeloggingfileobject(
                 ui, proc.stdout, b'o', logdata=True
             )
             stderr = util.makeloggingfileobject(
                 ui, proc.stderr, b'e', logdata=True
             )
 
         # --localssh also implies the peer connection settings.
 
         url = b'ssh://localserver'
         autoreadstderr = not opts[b'noreadstderr']
 
         if opts[b'peer'] == b'ssh1':
             ui.write(_(b'creating ssh peer for wire protocol version 1\n'))
             peer = sshpeer.sshv1peer(
                 ui,
                 url,
                 proc,
                 stdin,
                 stdout,
                 stderr,
                 None,
                 autoreadstderr=autoreadstderr,
             )
         elif opts[b'peer'] == b'raw':
             ui.write(_(b'using raw connection to peer\n'))
             peer = None
         else:
             ui.write(_(b'creating ssh peer from handshake results\n'))
             peer = sshpeer.makepeer(
                 ui,
                 url,
                 proc,
                 stdin,
                 stdout,
                 stderr,
                 autoreadstderr=autoreadstderr,
             )
 
     elif path:
         # We bypass hg.peer() so we can proxy the sockets.
         # TODO consider not doing this because we skip
         # ``hg.wirepeersetupfuncs`` and potentially other useful functionality.
         u = urlutil.url(path)
         if u.scheme != b'http':
             raise error.Abort(_(b'only http:// paths are currently supported'))
 
         url, authinfo = u.authinfo()
         openerargs = {
             'useragent': b'Mercurial debugwireproto',
         }
 
         # Turn pipes/sockets into observers so we can log I/O.
         if ui.verbose:
             openerargs.update(
                 {
                     'loggingfh': ui,
                     'loggingname': b's',
                     'loggingopts': {
                         'logdata': True,
                         'logdataapis': False,
                     },
                 }
             )
 
         if ui.debugflag:
             openerargs['loggingopts']['logdataapis'] = True
 
         # Don't send default headers when in raw mode. This allows us to
         # bypass most of the behavior of our URL handling code so we can
         # have near complete control over what's sent on the wire.
         if opts[b'peer'] == b'raw':
             openerargs['sendaccept'] = False
 
         opener = urlmod.opener(ui, authinfo, **openerargs)
 
         if opts[b'peer'] == b'raw':
             ui.write(_(b'using raw connection to peer\n'))
             peer = None
         elif opts[b'peer']:
             raise error.Abort(
                 _(b'--peer %s not supported with HTTP peers') % opts[b'peer']
             )
         else:
             peer_path = urlutil.try_path(ui, path)
             peer = httppeer.makepeer(ui, peer_path, opener=opener)
 
         # We /could/ populate stdin/stdout with sock.makefile()...
     else:
         raise error.Abort(_(b'unsupported connection configuration'))
 
     batchedcommands = None
 
     # Now perform actions based on the parsed wire language instructions.
     for action, lines in blocks:
         if action in (b'raw', b'raw+'):
             if not stdin:
                 raise error.Abort(_(b'cannot call raw/raw+ on this peer'))
 
             # Concatenate the data together.
             data = b''.join(l.lstrip() for l in lines)
             data = stringutil.unescapestr(data)
             stdin.write(data)
 
             if action == b'raw+':
                 stdin.flush()
         elif action == b'flush':
             if not stdin:
                 raise error.Abort(_(b'cannot call flush on this peer'))
             stdin.flush()
         elif action.startswith(b'command'):
             if not peer:
                 raise error.Abort(
                     _(
                         b'cannot send commands unless peer instance '
                         b'is available'
                     )
                 )
 
             command = action.split(b' ', 1)[1]
 
             args = {}
             for line in lines:
                 # We need to allow empty values.
                 fields = line.lstrip().split(b' ', 1)
                 if len(fields) == 1:
                     key = fields[0]
                     value = b''
                 else:
                     key, value = fields
 
                 if value.startswith(b'eval:'):
                     value = stringutil.evalpythonliteral(value[5:])
                 else:
                     value = stringutil.unescapestr(value)
 
                 args[key] = value
 
             if batchedcommands is not None:
                 batchedcommands.append((command, args))
                 continue
 
             ui.status(_(b'sending %s command\n') % command)
 
             if b'PUSHFILE' in args:
                 with open(args[b'PUSHFILE'], 'rb') as fh:
                     del args[b'PUSHFILE']
                     res, output = peer._callpush(
                         command, fh, **pycompat.strkwargs(args)
                     )
                     ui.status(_(b'result: %s\n') % stringutil.escapestr(res))
                     ui.status(
                         _(b'remote output: %s\n') % stringutil.escapestr(output)
                     )
             else:
                 with peer.commandexecutor() as e:
                     res = e.callcommand(command, args).result()
 
                 ui.status(
                     _(b'response: %s\n')
                     % stringutil.pprint(res, bprefix=True, indent=2)
                 )
 
         elif action == b'batchbegin':
             if batchedcommands is not None:
                 raise error.Abort(_(b'nested batchbegin not allowed'))
 
             batchedcommands = []
         elif action == b'batchsubmit':
             # There is a batching API we could go through. But it would be
             # difficult to normalize requests into function calls. It is easier
             # to bypass this layer and normalize to commands + args.
             ui.status(
                 _(b'sending batch with %d sub-commands\n')
                 % len(batchedcommands)
             )
             assert peer is not None
             for i, chunk in enumerate(peer._submitbatch(batchedcommands)):
                 ui.status(
                     _(b'response #%d: %s\n') % (i, stringutil.escapestr(chunk))
                 )
 
             batchedcommands = None
 
         elif action.startswith(b'httprequest '):
             if not opener:
                 raise error.Abort(
                     _(b'cannot use httprequest without an HTTP peer')
                 )
 
             request = action.split(b' ', 2)
             if len(request) != 3:
                 raise error.Abort(
                     _(
                         b'invalid httprequest: expected format is '
                         b'"httprequest <method> <path>'
                     )
                 )
 
             method, httppath = request[1:]
             headers = {}
             body = None
             frames = []
             for line in lines:
                 line = line.lstrip()
                 m = re.match(b'^([a-zA-Z0-9_-]+): (.*)$', line)
                 if m:
                     # Headers need to use native strings.
                     key = pycompat.strurl(m.group(1))
                     value = pycompat.strurl(m.group(2))
                     headers[key] = value
                     continue
 
                 if line.startswith(b'BODYFILE '):
                     with open(line.split(b' ', 1), b'rb') as fh:
                         body = fh.read()
                 elif line.startswith(b'frame '):
                     frame = wireprotoframing.makeframefromhumanstring(
                         line[len(b'frame ') :]
                     )
 
                     frames.append(frame)
                 else:
                     raise error.Abort(
                         _(b'unknown argument to httprequest: %s') % line
                     )
 
             url = path + httppath
 
             if frames:
                 body = b''.join(bytes(f) for f in frames)
 
             req = urlmod.urlreq.request(pycompat.strurl(url), body, headers)
 
             # urllib.Request insists on using has_data() as a proxy for
             # determining the request method. Override that to use our
             # explicitly requested method.
             req.get_method = lambda: pycompat.sysstr(method)
 
             try:
                 res = opener.open(req)
                 body = res.read()
             except util.urlerr.urlerror as e:
                 # read() method must be called, but only exists in Python 2
                 getattr(e, 'read', lambda: None)()
                 continue
 
             ct = res.headers.get('Content-Type')
             if ct == 'application/mercurial-cbor':
                 ui.write(
                     _(b'cbor> %s\n')
                     % stringutil.pprint(
                         cborutil.decodeall(body), bprefix=True, indent=2
                     )
                 )
 
         elif action == b'close':
             assert peer is not None
             peer.close()
         elif action == b'readavailable':
             if not stdout or not stderr:
                 raise error.Abort(
                     _(b'readavailable not available on this peer')
                 )
 
             stdin.close()
             stdout.read()
             stderr.read()
 
         elif action == b'readline':
             if not stdout:
                 raise error.Abort(_(b'readline not available on this peer'))
             stdout.readline()
         elif action == b'ereadline':
             if not stderr:
                 raise error.Abort(_(b'ereadline not available on this peer'))
             stderr.readline()
         elif action.startswith(b'read '):
             count = int(action.split(b' ', 1)[1])
             if not stdout:
                 raise error.Abort(_(b'read not available on this peer'))
             stdout.read(count)
         elif action.startswith(b'eread '):
             count = int(action.split(b' ', 1)[1])
             if not stderr:
                 raise error.Abort(_(b'eread not available on this peer'))
             stderr.read(count)
         else:
             raise error.Abort(_(b'unknown action: %s') % action)
 
     if batchedcommands is not None:
         raise error.Abort(_(b'unclosed "batchbegin" request'))
 
     if peer:
         peer.close()
 
     if proc:
         proc.kill()

mercurial/util.py

@@ -1,3320 +1,3327 b''
 # util.py - Mercurial utility functions and platform specific implementations
 #
 #  Copyright 2005 K. Thananchayan <[e-mail]>
 #  Copyright 2005-2007 Olivia Mackall <[e-mail]>
 #  Copyright 2006 Vadim Gelfer <[e-mail]>
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 """Mercurial utility functions and platform specific implementations.
 
 This contains helper routines that are independent of the SCM core and
 hide platform-specific details from the core.
 """
 
 
 import abc
 import collections
 import contextlib
 import errno
 import gc
 import hashlib
 import io
 import itertools
 import locale
 import mmap
 import os
 import pickle  # provides util.pickle symbol
 import re as remod
 import shutil
 import stat
 import sys
 import time
 import traceback
 import warnings
 
 from .node import hex
 from .thirdparty import attr
 from .pycompat import (
     delattr,
     getattr,
     open,
     setattr,
 )
 from hgdemandimport import tracing
 from . import (
     encoding,
     error,
     i18n,
     policy,
     pycompat,
     urllibcompat,
 )
 from .utils import (
     compression,
     hashutil,
     procutil,
     stringutil,
 )
 
 if pycompat.TYPE_CHECKING:
     from typing import (
         Iterable,
         Iterator,
         List,
         Optional,
         Tuple,
     )
 
 
 base85 = policy.importmod('base85')
 osutil = policy.importmod('osutil')
 
 b85decode = base85.b85decode
 b85encode = base85.b85encode
 
 cookielib = pycompat.cookielib
 httplib = pycompat.httplib
 safehasattr = pycompat.safehasattr
 socketserver = pycompat.socketserver
 bytesio = io.BytesIO
 # TODO deprecate stringio name, as it is a lie on Python 3.
 stringio = bytesio
 xmlrpclib = pycompat.xmlrpclib
 
 httpserver = urllibcompat.httpserver
 urlerr = urllibcompat.urlerr
 urlreq = urllibcompat.urlreq
 
 # workaround for win32mbcs
 _filenamebytestr = pycompat.bytestr
 
 if pycompat.iswindows:
     from . import windows as platform
 else:
     from . import posix as platform
 
 _ = i18n._
 
 abspath = platform.abspath
 bindunixsocket = platform.bindunixsocket
 cachestat = platform.cachestat
 checkexec = platform.checkexec
 checklink = platform.checklink
 copymode = platform.copymode
 expandglobs = platform.expandglobs
 getfsmountpoint = platform.getfsmountpoint
 getfstype = platform.getfstype
 get_password = platform.get_password
 groupmembers = platform.groupmembers
 groupname = platform.groupname
 isexec = platform.isexec
 isowner = platform.isowner
 listdir = osutil.listdir
 localpath = platform.localpath
 lookupreg = platform.lookupreg
 makedir = platform.makedir
 nlinks = platform.nlinks
 normpath = platform.normpath
 normcase = platform.normcase
 normcasespec = platform.normcasespec
 normcasefallback = platform.normcasefallback
 openhardlinks = platform.openhardlinks
 oslink = platform.oslink
 parsepatchoutput = platform.parsepatchoutput
 pconvert = platform.pconvert
 poll = platform.poll
 posixfile = platform.posixfile
 readlink = platform.readlink
 rename = platform.rename
 removedirs = platform.removedirs
 samedevice = platform.samedevice
 samefile = platform.samefile
 samestat = platform.samestat
 setflags = platform.setflags
 split = platform.split
 statfiles = getattr(osutil, 'statfiles', platform.statfiles)
 statisexec = platform.statisexec
 statislink = platform.statislink
 umask = platform.umask
 unlink = platform.unlink
 username = platform.username
 
 
 def setumask(val):
     # type: (int) -> None
     '''updates the umask. used by chg server'''
     if pycompat.iswindows:
         return
     os.umask(val)
     global umask
     platform.umask = umask = val & 0o777
 
 
 # small compat layer
 compengines = compression.compengines
 SERVERROLE = compression.SERVERROLE
 CLIENTROLE = compression.CLIENTROLE
 
 # Python compatibility
 
 _notset = object()
 
 
 def bitsfrom(container):
     bits = 0
     for bit in container:
         bits |= bit
     return bits
 
 
 # python 2.6 still have deprecation warning enabled by default. We do not want
 # to display anything to standard user so detect if we are running test and
 # only use python deprecation warning in this case.
 _dowarn = bool(encoding.environ.get(b'HGEMITWARNINGS'))
 if _dowarn:
     # explicitly unfilter our warning for python 2.7
     #
     # The option of setting PYTHONWARNINGS in the test runner was investigated.
     # However, module name set through PYTHONWARNINGS was exactly matched, so
     # we cannot set 'mercurial' and have it match eg: 'mercurial.scmutil'. This
     # makes the whole PYTHONWARNINGS thing useless for our usecase.
     warnings.filterwarnings('default', '', DeprecationWarning, 'mercurial')
     warnings.filterwarnings('default', '', DeprecationWarning, 'hgext')
     warnings.filterwarnings('default', '', DeprecationWarning, 'hgext3rd')
 if _dowarn:
     # silence warning emitted by passing user string to re.sub()
     warnings.filterwarnings(
         'ignore', 'bad escape', DeprecationWarning, 'mercurial'
     )
     warnings.filterwarnings(
         'ignore', 'invalid escape sequence', DeprecationWarning, 'mercurial'
     )
     # TODO: reinvent imp.is_frozen()
     warnings.filterwarnings(
         'ignore',
         'the imp module is deprecated',
         DeprecationWarning,
         'mercurial',
     )
 
 
 def nouideprecwarn(msg, version, stacklevel=1):
     """Issue an python native deprecation warning
 
     This is a noop outside of tests, use 'ui.deprecwarn' when possible.
     """
     if _dowarn:
         msg += (
             b"\n(compatibility will be dropped after Mercurial-%s,"
             b" update your code.)"
         ) % version
         warnings.warn(pycompat.sysstr(msg), DeprecationWarning, stacklevel + 1)
         # on python 3 with chg, we will need to explicitly flush the output
         sys.stderr.flush()
 
 
 DIGESTS = {
     b'md5': hashlib.md5,
     b'sha1': hashutil.sha1,
     b'sha512': hashlib.sha512,
 }
 # List of digest types from strongest to weakest
 DIGESTS_BY_STRENGTH = [b'sha512', b'sha1', b'md5']
 
 for k in DIGESTS_BY_STRENGTH:
     assert k in DIGESTS
 
 
 class digester:
     """helper to compute digests.
 
     This helper can be used to compute one or more digests given their name.
 
     >>> d = digester([b'md5', b'sha1'])
     >>> d.update(b'foo')
     >>> [k for k in sorted(d)]
     ['md5', 'sha1']
     >>> d[b'md5']
     'acbd18db4cc2f85cedef654fccc4a4d8'
     >>> d[b'sha1']
     '0beec7b5ea3f0fdbc95d0dd47f3c5bc275da8a33'
     >>> digester.preferred([b'md5', b'sha1'])
     'sha1'
     """
 
     def __init__(self, digests, s=b''):
         self._hashes = {}
         for k in digests:
             if k not in DIGESTS:
                 raise error.Abort(_(b'unknown digest type: %s') % k)
             self._hashes[k] = DIGESTS[k]()
         if s:
             self.update(s)
 
     def update(self, data):
         for h in self._hashes.values():
             h.update(data)
 
     def __getitem__(self, key):
         if key not in DIGESTS:
             raise error.Abort(_(b'unknown digest type: %s') % k)
         return hex(self._hashes[key].digest())
 
     def __iter__(self):
         return iter(self._hashes)
 
     @staticmethod
     def preferred(supported):
         """returns the strongest digest type in both supported and DIGESTS."""
 
         for k in DIGESTS_BY_STRENGTH:
             if k in supported:
                 return k
         return None
 
 
 class digestchecker:
     """file handle wrapper that additionally checks content against a given
     size and digests.
 
         d = digestchecker(fh, size, {'md5': '...'})
 
     When multiple digests are given, all of them are validated.
     """
 
     def __init__(self, fh, size, digests):
         self._fh = fh
         self._size = size
         self._got = 0
         self._digests = dict(digests)
         self._digester = digester(self._digests.keys())
 
     def read(self, length=-1):
         content = self._fh.read(length)
         self._digester.update(content)
         self._got += len(content)
         return content
 
     def validate(self):
         if self._size != self._got:
             raise error.Abort(
                 _(b'size mismatch: expected %d, got %d')
                 % (self._size, self._got)
             )
         for k, v in self._digests.items():
             if v != self._digester[k]:
                 # i18n: first parameter is a digest name
                 raise error.Abort(
                     _(b'%s mismatch: expected %s, got %s')
                     % (k, v, self._digester[k])
                 )
 
 
 try:
     buffer = buffer  # pytype: disable=name-error
 except NameError:
 
     def buffer(sliceable, offset=0, length=None):
         if length is not None:
             return memoryview(sliceable)[offset : offset + length]
         return memoryview(sliceable)[offset:]
 
 
 _chunksize = 4096
 
 
 class bufferedinputpipe:
     """a manually buffered input pipe
 
     Python will not let us use buffered IO and lazy reading with 'polling' at
     the same time. We cannot probe the buffer state and select will not detect
     that data are ready to read if they are already buffered.
 
     This class let us work around that by implementing its own buffering
     (allowing efficient readline) while offering a way to know if the buffer is
     empty from the output (allowing collaboration of the buffer with polling).
 
     This class lives in the 'util' module because it makes use of the 'os'
     module from the python stdlib.
     """
 
     def __new__(cls, fh):
         # If we receive a fileobjectproxy, we need to use a variation of this
         # class that notifies observers about activity.
         if isinstance(fh, fileobjectproxy):
             cls = observedbufferedinputpipe
 
         return super(bufferedinputpipe, cls).__new__(cls)
 
     def __init__(self, input):
         self._input = input
         self._buffer = []
         self._eof = False
         self._lenbuf = 0
 
     @property
     def hasbuffer(self):
         """True is any data is currently buffered
 
         This will be used externally a pre-step for polling IO. If there is
         already data then no polling should be set in place."""
         return bool(self._buffer)
 
     @property
     def closed(self):
         return self._input.closed
 
     def fileno(self):
         return self._input.fileno()
 
     def close(self):
         return self._input.close()
 
     def read(self, size):
         while (not self._eof) and (self._lenbuf < size):
             self._fillbuffer()
         return self._frombuffer(size)
 
     def unbufferedread(self, size):
         if not self._eof and self._lenbuf == 0:
             self._fillbuffer(max(size, _chunksize))
         return self._frombuffer(min(self._lenbuf, size))
 
     def readline(self, *args, **kwargs):
         if len(self._buffer) > 1:
             # this should not happen because both read and readline end with a
             # _frombuffer call that collapse it.
             self._buffer = [b''.join(self._buffer)]
             self._lenbuf = len(self._buffer[0])
         lfi = -1
         if self._buffer:
             lfi = self._buffer[-1].find(b'\n')
         while (not self._eof) and lfi < 0:
             self._fillbuffer()
             if self._buffer:
                 lfi = self._buffer[-1].find(b'\n')
         size = lfi + 1
         if lfi < 0:  # end of file
             size = self._lenbuf
         elif len(self._buffer) > 1:
             # we need to take previous chunks into account
             size += self._lenbuf - len(self._buffer[-1])
         return self._frombuffer(size)
 
     def _frombuffer(self, size):
         """return at most 'size' data from the buffer
 
         The data are removed from the buffer."""
         if size == 0 or not self._buffer:
             return b''
         buf = self._buffer[0]
         if len(self._buffer) > 1:
             buf = b''.join(self._buffer)
 
         data = buf[:size]
         buf = buf[len(data) :]
         if buf:
             self._buffer = [buf]
             self._lenbuf = len(buf)
         else:
             self._buffer = []
             self._lenbuf = 0
         return data
 
     def _fillbuffer(self, size=_chunksize):
         """read data to the buffer"""
         data = os.read(self._input.fileno(), size)
         if not data:
             self._eof = True
         else:
             self._lenbuf += len(data)
             self._buffer.append(data)
 
         return data
 
 
 def mmapread(fp, size=None):
     if size == 0:
         # size of 0 to mmap.mmap() means "all data"
         # rather than "zero bytes", so special case that.
         return b''
     elif size is None:
         size = 0
     fd = getattr(fp, 'fileno', lambda: fp)()
     try:
         return mmap.mmap(fd, size, access=mmap.ACCESS_READ)
     except ValueError:
         # Empty files cannot be mmapped, but mmapread should still work.  Check
         # if the file is empty, and if so, return an empty buffer.
         if os.fstat(fd).st_size == 0:
             return b''
         raise
 
 
 class fileobjectproxy:
     """A proxy around file objects that tells a watcher when events occur.
 
     This type is intended to only be used for testing purposes. Think hard
     before using it in important code.
     """
 
     __slots__ = (
         '_orig',
         '_observer',
     )
 
     def __init__(self, fh, observer):
         object.__setattr__(self, '_orig', fh)
         object.__setattr__(self, '_observer', observer)
 
     def __getattribute__(self, name):
         ours = {
             '_observer',
             # IOBase
             'close',
             # closed if a property
             'fileno',
             'flush',
             'isatty',
             'readable',
             'readline',
             'readlines',
             'seek',
             'seekable',
             'tell',
             'truncate',
             'writable',
             'writelines',
             # RawIOBase
             'read',
             'readall',
             'readinto',
             'write',
             # BufferedIOBase
             # raw is a property
             'detach',
             # read defined above
             'read1',
             # readinto defined above
             # write defined above
         }
 
         # We only observe some methods.
         if name in ours:
             return object.__getattribute__(self, name)
 
         return getattr(object.__getattribute__(self, '_orig'), name)
 
     def __nonzero__(self):
         return bool(object.__getattribute__(self, '_orig'))
 
     __bool__ = __nonzero__
 
     def __delattr__(self, name):
         return delattr(object.__getattribute__(self, '_orig'), name)
 
     def __setattr__(self, name, value):
         return setattr(object.__getattribute__(self, '_orig'), name, value)
 
     def __iter__(self):
         return object.__getattribute__(self, '_orig').__iter__()
 
     def _observedcall(self, name, *args, **kwargs):
         # Call the original object.
         orig = object.__getattribute__(self, '_orig')
         res = getattr(orig, name)(*args, **kwargs)
 
         # Call a method on the observer of the same name with arguments
         # so it can react, log, etc.
         observer = object.__getattribute__(self, '_observer')
         fn = getattr(observer, name, None)
         if fn:
             fn(res, *args, **kwargs)
 
         return res
 
     def close(self, *args, **kwargs):
         return object.__getattribute__(self, '_observedcall')(
             'close', *args, **kwargs
         )
 
     def fileno(self, *args, **kwargs):
         return object.__getattribute__(self, '_observedcall')(
             'fileno', *args, **kwargs
         )
 
     def flush(self, *args, **kwargs):
         return object.__getattribute__(self, '_observedcall')(
             'flush', *args, **kwargs
         )
 
     def isatty(self, *args, **kwargs):
         return object.__getattribute__(self, '_observedcall')(
             'isatty', *args, **kwargs
         )
 
     def readable(self, *args, **kwargs):
         return object.__getattribute__(self, '_observedcall')(
             'readable', *args, **kwargs
         )
 
     def readline(self, *args, **kwargs):
         return object.__getattribute__(self, '_observedcall')(
             'readline', *args, **kwargs
         )
 
     def readlines(self, *args, **kwargs):
         return object.__getattribute__(self, '_observedcall')(
             'readlines', *args, **kwargs
         )
 
     def seek(self, *args, **kwargs):
         return object.__getattribute__(self, '_observedcall')(
             'seek', *args, **kwargs
         )
 
     def seekable(self, *args, **kwargs):
         return object.__getattribute__(self, '_observedcall')(
             'seekable', *args, **kwargs
         )
 
     def tell(self, *args, **kwargs):
         return object.__getattribute__(self, '_observedcall')(
             'tell', *args, **kwargs
         )
 
     def truncate(self, *args, **kwargs):
         return object.__getattribute__(self, '_observedcall')(
             'truncate', *args, **kwargs
         )
 
     def writable(self, *args, **kwargs):
         return object.__getattribute__(self, '_observedcall')(
             'writable', *args, **kwargs
         )
 
     def writelines(self, *args, **kwargs):
         return object.__getattribute__(self, '_observedcall')(
             'writelines', *args, **kwargs
         )
 
     def read(self, *args, **kwargs):
         return object.__getattribute__(self, '_observedcall')(
             'read', *args, **kwargs
         )
 
     def readall(self, *args, **kwargs):
         return object.__getattribute__(self, '_observedcall')(
             'readall', *args, **kwargs
         )
 
     def readinto(self, *args, **kwargs):
         return object.__getattribute__(self, '_observedcall')(
             'readinto', *args, **kwargs
         )
 
     def write(self, *args, **kwargs):
         return object.__getattribute__(self, '_observedcall')(
             'write', *args, **kwargs
         )
 
     def detach(self, *args, **kwargs):
         return object.__getattribute__(self, '_observedcall')(
             'detach', *args, **kwargs
         )
 
     def read1(self, *args, **kwargs):
         return object.__getattribute__(self, '_observedcall')(
             'read1', *args, **kwargs
         )
 
 
 class observedbufferedinputpipe(bufferedinputpipe):
     """A variation of bufferedinputpipe that is aware of fileobjectproxy.
 
     ``bufferedinputpipe`` makes low-level calls to ``os.read()`` that
     bypass ``fileobjectproxy``. Because of this, we need to make
     ``bufferedinputpipe`` aware of these operations.
 
     This variation of ``bufferedinputpipe`` can notify observers about
     ``os.read()`` events. It also re-publishes other events, such as
     ``read()`` and ``readline()``.
     """
 
     def _fillbuffer(self, size=_chunksize):
         res = super(observedbufferedinputpipe, self)._fillbuffer(size=size)
 
         fn = getattr(self._input._observer, 'osread', None)
         if fn:
             fn(res, size)
 
         return res
 
     # We use different observer methods because the operation isn't
     # performed on the actual file object but on us.
     def read(self, size):
         res = super(observedbufferedinputpipe, self).read(size)
 
         fn = getattr(self._input._observer, 'bufferedread', None)
         if fn:
             fn(res, size)
 
         return res
 
     def readline(self, *args, **kwargs):
         res = super(observedbufferedinputpipe, self).readline(*args, **kwargs)
 
         fn = getattr(self._input._observer, 'bufferedreadline', None)
         if fn:
             fn(res)
 
         return res
 
 
 PROXIED_SOCKET_METHODS = {
     'makefile',
     'recv',
     'recvfrom',
     'recvfrom_into',
     'recv_into',
     'send',
     'sendall',
     'sendto',
     'setblocking',
     'settimeout',
     'gettimeout',
     'setsockopt',
 }
 
 
 class socketproxy:
     """A proxy around a socket that tells a watcher when events occur.
 
     This is like ``fileobjectproxy`` except for sockets.
 
     This type is intended to only be used for testing purposes. Think hard
     before using it in important code.
     """
 
     __slots__ = (
         '_orig',
         '_observer',
     )
 
     def __init__(self, sock, observer):
         object.__setattr__(self, '_orig', sock)
         object.__setattr__(self, '_observer', observer)
 
     def __getattribute__(self, name):
         if name in PROXIED_SOCKET_METHODS:
             return object.__getattribute__(self, name)
 
         return getattr(object.__getattribute__(self, '_orig'), name)
 
     def __delattr__(self, name):
         return delattr(object.__getattribute__(self, '_orig'), name)
 
     def __setattr__(self, name, value):
         return setattr(object.__getattribute__(self, '_orig'), name, value)
 
     def __nonzero__(self):
         return bool(object.__getattribute__(self, '_orig'))
 
     __bool__ = __nonzero__
 
     def _observedcall(self, name, *args, **kwargs):
         # Call the original object.
         orig = object.__getattribute__(self, '_orig')
         res = getattr(orig, name)(*args, **kwargs)
 
         # Call a method on the observer of the same name with arguments
         # so it can react, log, etc.
         observer = object.__getattribute__(self, '_observer')
         fn = getattr(observer, name, None)
         if fn:
             fn(res, *args, **kwargs)
 
         return res
 
     def makefile(self, *args, **kwargs):
         res = object.__getattribute__(self, '_observedcall')(
             'makefile', *args, **kwargs
         )
 
         # The file object may be used for I/O. So we turn it into a
         # proxy using our observer.
         observer = object.__getattribute__(self, '_observer')
         return makeloggingfileobject(
             observer.fh,
             res,
             observer.name,
             reads=observer.reads,
             writes=observer.writes,
             logdata=observer.logdata,
             logdataapis=observer.logdataapis,
         )
 
     def recv(self, *args, **kwargs):
         return object.__getattribute__(self, '_observedcall')(
             'recv', *args, **kwargs
         )
 
     def recvfrom(self, *args, **kwargs):
         return object.__getattribute__(self, '_observedcall')(
             'recvfrom', *args, **kwargs
         )
 
     def recvfrom_into(self, *args, **kwargs):
         return object.__getattribute__(self, '_observedcall')(
             'recvfrom_into', *args, **kwargs
         )
 
     def recv_into(self, *args, **kwargs):
         return object.__getattribute__(self, '_observedcall')(
             'recv_info', *args, **kwargs
         )
 
     def send(self, *args, **kwargs):
         return object.__getattribute__(self, '_observedcall')(
             'send', *args, **kwargs
         )
 
     def sendall(self, *args, **kwargs):
         return object.__getattribute__(self, '_observedcall')(
             'sendall', *args, **kwargs
         )
 
     def sendto(self, *args, **kwargs):
         return object.__getattribute__(self, '_observedcall')(
             'sendto', *args, **kwargs
         )
 
     def setblocking(self, *args, **kwargs):
         return object.__getattribute__(self, '_observedcall')(
             'setblocking', *args, **kwargs
         )
 
     def settimeout(self, *args, **kwargs):
         return object.__getattribute__(self, '_observedcall')(
             'settimeout', *args, **kwargs
         )
 
     def gettimeout(self, *args, **kwargs):
         return object.__getattribute__(self, '_observedcall')(
             'gettimeout', *args, **kwargs
         )
 
     def setsockopt(self, *args, **kwargs):
         return object.__getattribute__(self, '_observedcall')(
             'setsockopt', *args, **kwargs
         )
 
 
 class baseproxyobserver:
     def __init__(self, fh, name, logdata, logdataapis):
         self.fh = fh
         self.name = name
         self.logdata = logdata
         self.logdataapis = logdataapis
 
     def _writedata(self, data):
         if not self.logdata:
             if self.logdataapis:
                 self.fh.write(b'\n')
                 self.fh.flush()
             return
 
         # Simple case writes all data on a single line.
         if b'\n' not in data:
             if self.logdataapis:
                 self.fh.write(b': %s\n' % stringutil.escapestr(data))
             else:
                 self.fh.write(
                     b'%s>     %s\n' % (self.name, stringutil.escapestr(data))
                 )
             self.fh.flush()
             return
 
         # Data with newlines is written to multiple lines.
         if self.logdataapis:
             self.fh.write(b':\n')
 
         lines = data.splitlines(True)
         for line in lines:
             self.fh.write(
                 b'%s>     %s\n' % (self.name, stringutil.escapestr(line))
             )
         self.fh.flush()
 
 
 class fileobjectobserver(baseproxyobserver):
     """Logs file object activity."""
 
     def __init__(
         self, fh, name, reads=True, writes=True, logdata=False, logdataapis=True
     ):
         super(fileobjectobserver, self).__init__(fh, name, logdata, logdataapis)
         self.reads = reads
         self.writes = writes
 
     def read(self, res, size=-1):
         if not self.reads:
             return
         # Python 3 can return None from reads at EOF instead of empty strings.
         if res is None:
             res = b''
 
         if size == -1 and res == b'':
             # Suppress pointless read(-1) calls that return
             # nothing. These happen _a lot_ on Python 3, and there
             # doesn't seem to be a better workaround to have matching
             # Python 2 and 3 behavior. :(
             return
 
         if self.logdataapis:
             self.fh.write(b'%s> read(%d) -> %d' % (self.name, size, len(res)))
 
         self._writedata(res)
 
     def readline(self, res, limit=-1):
         if not self.reads:
             return
 
         if self.logdataapis:
             self.fh.write(b'%s> readline() -> %d' % (self.name, len(res)))
 
         self._writedata(res)
 
     def readinto(self, res, dest):
         if not self.reads:
             return
 
         if self.logdataapis:
             self.fh.write(
                 b'%s> readinto(%d) -> %r' % (self.name, len(dest), res)
             )
 
         data = dest[0:res] if res is not None else b''
 
         # _writedata() uses "in" operator and is confused by memoryview because
         # characters are ints on Python 3.
         if isinstance(data, memoryview):
             data = data.tobytes()
 
         self._writedata(data)
 
     def write(self, res, data):
         if not self.writes:
             return
 
         # Python 2 returns None from some write() calls. Python 3 (reasonably)
         # returns the integer bytes written.
         if res is None and data:
             res = len(data)
 
         if self.logdataapis:
             self.fh.write(b'%s> write(%d) -> %r' % (self.name, len(data), res))
 
         self._writedata(data)
 
     def flush(self, res):
         if not self.writes:
             return
 
         self.fh.write(b'%s> flush() -> %r\n' % (self.name, res))
 
     # For observedbufferedinputpipe.
     def bufferedread(self, res, size):
         if not self.reads:
             return
 
         if self.logdataapis:
             self.fh.write(
                 b'%s> bufferedread(%d) -> %d' % (self.name, size, len(res))
             )
 
         self._writedata(res)
 
     def bufferedreadline(self, res):
         if not self.reads:
             return
 
         if self.logdataapis:
             self.fh.write(
                 b'%s> bufferedreadline() -> %d' % (self.name, len(res))
             )
 
         self._writedata(res)
 
 
 def makeloggingfileobject(
     logh, fh, name, reads=True, writes=True, logdata=False, logdataapis=True
 ):
     """Turn a file object into a logging file object."""
 
     observer = fileobjectobserver(
         logh,
         name,
         reads=reads,
         writes=writes,
         logdata=logdata,
         logdataapis=logdataapis,
     )
     return fileobjectproxy(fh, observer)
 
 
 class socketobserver(baseproxyobserver):
     """Logs socket activity."""
 
     def __init__(
         self,
         fh,
         name,
         reads=True,
         writes=True,
         states=True,
         logdata=False,
         logdataapis=True,
     ):
         super(socketobserver, self).__init__(fh, name, logdata, logdataapis)
         self.reads = reads
         self.writes = writes
         self.states = states
 
     def makefile(self, res, mode=None, bufsize=None):
         if not self.states:
             return
 
         self.fh.write(b'%s> makefile(%r, %r)\n' % (self.name, mode, bufsize))
 
     def recv(self, res, size, flags=0):
         if not self.reads:
             return
 
         if self.logdataapis:
             self.fh.write(
                 b'%s> recv(%d, %d) -> %d' % (self.name, size, flags, len(res))
             )
         self._writedata(res)
 
     def recvfrom(self, res, size, flags=0):
         if not self.reads:
             return
 
         if self.logdataapis:
             self.fh.write(
                 b'%s> recvfrom(%d, %d) -> %d'
                 % (self.name, size, flags, len(res[0]))
             )
 
         self._writedata(res[0])
 
     def recvfrom_into(self, res, buf, size, flags=0):
         if not self.reads:
             return
 
         if self.logdataapis:
             self.fh.write(
                 b'%s> recvfrom_into(%d, %d) -> %d'
                 % (self.name, size, flags, res[0])
             )
 
         self._writedata(buf[0 : res[0]])
 
     def recv_into(self, res, buf, size=0, flags=0):
         if not self.reads:
             return
 
         if self.logdataapis:
             self.fh.write(
                 b'%s> recv_into(%d, %d) -> %d' % (self.name, size, flags, res)
             )
 
         self._writedata(buf[0:res])
 
     def send(self, res, data, flags=0):
         if not self.writes:
             return
 
         self.fh.write(
             b'%s> send(%d, %d) -> %d' % (self.name, len(data), flags, len(res))
         )
         self._writedata(data)
 
     def sendall(self, res, data, flags=0):
         if not self.writes:
             return
 
         if self.logdataapis:
             # Returns None on success. So don't bother reporting return value.
             self.fh.write(
                 b'%s> sendall(%d, %d)' % (self.name, len(data), flags)
             )
 
         self._writedata(data)
 
     def sendto(self, res, data, flagsoraddress, address=None):
         if not self.writes:
             return
 
         if address:
             flags = flagsoraddress
         else:
             flags = 0
 
         if self.logdataapis:
             self.fh.write(
                 b'%s> sendto(%d, %d, %r) -> %d'
                 % (self.name, len(data), flags, address, res)
             )
 
         self._writedata(data)
 
     def setblocking(self, res, flag):
         if not self.states:
             return
 
         self.fh.write(b'%s> setblocking(%r)\n' % (self.name, flag))
 
     def settimeout(self, res, value):
         if not self.states:
             return
 
         self.fh.write(b'%s> settimeout(%r)\n' % (self.name, value))
 
     def gettimeout(self, res):
         if not self.states:
             return
 
         self.fh.write(b'%s> gettimeout() -> %f\n' % (self.name, res))
 
     def setsockopt(self, res, level, optname, value):
         if not self.states:
             return
 
         self.fh.write(
             b'%s> setsockopt(%r, %r, %r) -> %r\n'
             % (self.name, level, optname, value, res)
         )
 
 
 def makeloggingsocket(
     logh,
     fh,
     name,
     reads=True,
     writes=True,
     states=True,
     logdata=False,
     logdataapis=True,
 ):
     """Turn a socket into a logging socket."""
 
     observer = socketobserver(
         logh,
         name,
         reads=reads,
         writes=writes,
         states=states,
         logdata=logdata,
         logdataapis=logdataapis,
     )
     return socketproxy(fh, observer)
 
 
 def version():
     """Return version information if available."""
     try:
         from . import __version__
 
         return __version__.version
     except ImportError:
         return b'unknown'
 
 
 def versiontuple(v=None, n=4):
     """Parses a Mercurial version string into an N-tuple.
 
     The version string to be parsed is specified with the ``v`` argument.
     If it isn't defined, the current Mercurial version string will be parsed.
 
     ``n`` can be 2, 3, or 4. Here is how some version strings map to
     returned values:
 
     >>> v = b'3.6.1+190-df9b73d2d444'
     >>> versiontuple(v, 2)
     (3, 6)
     >>> versiontuple(v, 3)
     (3, 6, 1)
     >>> versiontuple(v, 4)
     (3, 6, 1, '190-df9b73d2d444')
 
     >>> versiontuple(b'3.6.1+190-df9b73d2d444+20151118')
     (3, 6, 1, '190-df9b73d2d444+20151118')
 
     >>> v = b'3.6'
     >>> versiontuple(v, 2)
     (3, 6)
     >>> versiontuple(v, 3)
     (3, 6, None)
     >>> versiontuple(v, 4)
     (3, 6, None, None)
 
     >>> v = b'3.9-rc'
     >>> versiontuple(v, 2)
     (3, 9)
     >>> versiontuple(v, 3)
     (3, 9, None)
     >>> versiontuple(v, 4)
     (3, 9, None, 'rc')
 
     >>> v = b'3.9-rc+2-02a8fea4289b'
     >>> versiontuple(v, 2)
     (3, 9)
     >>> versiontuple(v, 3)
     (3, 9, None)
     >>> versiontuple(v, 4)
     (3, 9, None, 'rc+2-02a8fea4289b')
 
     >>> versiontuple(b'4.6rc0')
     (4, 6, None, 'rc0')
     >>> versiontuple(b'4.6rc0+12-425d55e54f98')
     (4, 6, None, 'rc0+12-425d55e54f98')
     >>> versiontuple(b'.1.2.3')
     (None, None, None, '.1.2.3')
     >>> versiontuple(b'12.34..5')
     (12, 34, None, '..5')
     >>> versiontuple(b'1.2.3.4.5.6')
     (1, 2, 3, '.4.5.6')
     """
     if not v:
         v = version()
     m = remod.match(br'(\d+(?:\.\d+){,2})[+-]?(.*)', v)
     if not m:
         vparts, extra = b'', v
     elif m.group(2):
         vparts, extra = m.groups()
     else:
         vparts, extra = m.group(1), None
 
     assert vparts is not None  # help pytype
 
     vints = []
     for i in vparts.split(b'.'):
         try:
             vints.append(int(i))
         except ValueError:
             break
     # (3, 6) -> (3, 6, None)
     while len(vints) < 3:
         vints.append(None)
 
     if n == 2:
         return (vints[0], vints[1])
     if n == 3:
         return (vints[0], vints[1], vints[2])
     if n == 4:
         return (vints[0], vints[1], vints[2], extra)
 
     raise error.ProgrammingError(b"invalid version part request: %d" % n)
 
 
 def cachefunc(func):
     '''cache the result of function calls'''
     # XXX doesn't handle keywords args
     if func.__code__.co_argcount == 0:
         listcache = []
 
         def f():
             if len(listcache) == 0:
                 listcache.append(func())
             return listcache[0]
 
         return f
     cache = {}
     if func.__code__.co_argcount == 1:
         # we gain a small amount of time because
         # we don't need to pack/unpack the list
         def f(arg):
             if arg not in cache:
                 cache[arg] = func(arg)
             return cache[arg]
 
     else:
 
         def f(*args):
             if args not in cache:
                 cache[args] = func(*args)
             return cache[args]
 
     return f
 
 
 class cow:
     """helper class to make copy-on-write easier
 
     Call preparewrite before doing any writes.
     """
 
     def preparewrite(self):
         """call this before writes, return self or a copied new object"""
         if getattr(self, '_copied', 0):
             self._copied -= 1
             # Function cow.__init__ expects 1 arg(s), got 2 [wrong-arg-count]
             return self.__class__(self)  # pytype: disable=wrong-arg-count
         return self
 
     def copy(self):
         """always do a cheap copy"""
         self._copied = getattr(self, '_copied', 0) + 1
         return self
 
 
 class sortdict(collections.OrderedDict):
     """a simple sorted dictionary
 
     >>> d1 = sortdict([(b'a', 0), (b'b', 1)])
     >>> d2 = d1.copy()
     >>> d2
     sortdict([('a', 0), ('b', 1)])
     >>> d2.update([(b'a', 2)])
     >>> list(d2.keys()) # should still be in last-set order
     ['b', 'a']
     >>> d1.insert(1, b'a.5', 0.5)
     >>> d1
     sortdict([('a', 0), ('a.5', 0.5), ('b', 1)])
     """
 
     def __setitem__(self, key, value):
         if key in self:
             del self[key]
         super(sortdict, self).__setitem__(key, value)
 
     if pycompat.ispypy:
         # __setitem__() isn't called as of PyPy 5.8.0
         def update(self, src, **f):
             if isinstance(src, dict):
                 src = src.items()
             for k, v in src:
                 self[k] = v
             for k in f:
                 self[k] = f[k]
 
     def insert(self, position, key, value):
         for (i, (k, v)) in enumerate(list(self.items())):
             if i == position:
                 self[key] = value
             if i >= position:
                 del self[k]
                 self[k] = v
 
 
 class cowdict(cow, dict):
     """copy-on-write dict
 
     Be sure to call d = d.preparewrite() before writing to d.
 
     >>> a = cowdict()
     >>> a is a.preparewrite()
     True
     >>> b = a.copy()
     >>> b is a
     True
     >>> c = b.copy()
     >>> c is a
     True
     >>> a = a.preparewrite()
     >>> b is a
     False
     >>> a is a.preparewrite()
     True
     >>> c = c.preparewrite()
     >>> b is c
     False
     >>> b is b.preparewrite()
     True
     """
 
 
 class cowsortdict(cow, sortdict):
     """copy-on-write sortdict
 
     Be sure to call d = d.preparewrite() before writing to d.
     """
 
 
 class transactional:  # pytype: disable=ignored-metaclass
     """Base class for making a transactional type into a context manager."""
 
     __metaclass__ = abc.ABCMeta
 
     @abc.abstractmethod
     def close(self):
         """Successfully closes the transaction."""
 
     @abc.abstractmethod
     def release(self):
         """Marks the end of the transaction.
 
         If the transaction has not been closed, it will be aborted.
         """
 
     def __enter__(self):
         return self
 
     def __exit__(self, exc_type, exc_val, exc_tb):
         try:
             if exc_type is None:
                 self.close()
         finally:
             self.release()
 
 
 @contextlib.contextmanager
 def acceptintervention(tr=None):
     """A context manager that closes the transaction on InterventionRequired
 
     If no transaction was provided, this simply runs the body and returns
     """
     if not tr:
         yield
         return
     try:
         yield
         tr.close()
     except error.InterventionRequired:
         tr.close()
         raise
     finally:
         tr.release()
 
 
 @contextlib.contextmanager
 def nullcontextmanager(enter_result=None):
     yield enter_result
 
 
 class _lrucachenode:
     """A node in a doubly linked list.
 
     Holds a reference to nodes on either side as well as a key-value
     pair for the dictionary entry.
     """
 
     __slots__ = ('next', 'prev', 'key', 'value', 'cost')
 
     def __init__(self):
         self.next = self
         self.prev = self
 
         self.key = _notset
         self.value = None
         self.cost = 0
 
     def markempty(self):
         """Mark the node as emptied."""
         self.key = _notset
         self.value = None
         self.cost = 0
 
 
 class lrucachedict:
     """Dict that caches most recent accesses and sets.
 
     The dict consists of an actual backing dict - indexed by original
     key - and a doubly linked circular list defining the order of entries in
     the cache.
 
     The head node is the newest entry in the cache. If the cache is full,
     we recycle head.prev and make it the new head. Cache accesses result in
     the node being moved to before the existing head and being marked as the
     new head node.
 
     Items in the cache can be inserted with an optional "cost" value. This is
     simply an integer that is specified by the caller. The cache can be queried
     for the total cost of all items presently in the cache.
 
     The cache can also define a maximum cost. If a cache insertion would
     cause the total cost of the cache to go beyond the maximum cost limit,
     nodes will be evicted to make room for the new code. This can be used
     to e.g. set a max memory limit and associate an estimated bytes size
     cost to each item in the cache. By default, no maximum cost is enforced.
     """
 
     def __init__(self, max, maxcost=0):
         self._cache = {}
 
         self._head = _lrucachenode()
         self._size = 1
         self.capacity = max
         self.totalcost = 0
         self.maxcost = maxcost
 
     def __len__(self):
         return len(self._cache)
 
     def __contains__(self, k):
         return k in self._cache
 
     def __iter__(self):
         # We don't have to iterate in cache order, but why not.
         n = self._head
         for i in range(len(self._cache)):
             yield n.key
             n = n.next
 
     def __getitem__(self, k):
         node = self._cache[k]
         self._movetohead(node)
         return node.value
 
     def insert(self, k, v, cost=0):
         """Insert a new item in the cache with optional cost value."""
         node = self._cache.get(k)
         # Replace existing value and mark as newest.
         if node is not None:
             self.totalcost -= node.cost
             node.value = v
             node.cost = cost
             self.totalcost += cost
             self._movetohead(node)
 
             if self.maxcost:
                 self._enforcecostlimit()
 
             return
 
         if self._size < self.capacity:
             node = self._addcapacity()
         else:
             # Grab the last/oldest item.
             node = self._head.prev
 
         # At capacity. Kill the old entry.
         if node.key is not _notset:
             self.totalcost -= node.cost
             del self._cache[node.key]
 
         node.key = k
         node.value = v
         node.cost = cost
         self.totalcost += cost
         self._cache[k] = node
         # And mark it as newest entry. No need to adjust order since it
         # is already self._head.prev.
         self._head = node
 
         if self.maxcost:
             self._enforcecostlimit()
 
     def __setitem__(self, k, v):
         self.insert(k, v)
 
     def __delitem__(self, k):
         self.pop(k)
 
     def pop(self, k, default=_notset):
         try:
             node = self._cache.pop(k)
         except KeyError:
             if default is _notset:
                 raise
             return default
 
         assert node is not None  # help pytype
         value = node.value
         self.totalcost -= node.cost
         node.markempty()
 
         # Temporarily mark as newest item before re-adjusting head to make
         # this node the oldest item.
         self._movetohead(node)
         self._head = node.next
 
         return value
 
     # Additional dict methods.
 
     def get(self, k, default=None):
         try:
             return self.__getitem__(k)
         except KeyError:
             return default
 
     def peek(self, k, default=_notset):
         """Get the specified item without moving it to the head
 
         Unlike get(), this doesn't mutate the internal state. But be aware
         that it doesn't mean peek() is thread safe.
         """
         try:
             node = self._cache[k]
             assert node is not None  # help pytype
             return node.value
         except KeyError:
             if default is _notset:
                 raise
             return default
 
     def clear(self):
         n = self._head
         while n.key is not _notset:
             self.totalcost -= n.cost
             n.markempty()
             n = n.next
 
         self._cache.clear()
 
     def copy(self, capacity=None, maxcost=0):
         """Create a new cache as a copy of the current one.
 
         By default, the new cache has the same capacity as the existing one.
         But, the cache capacity can be changed as part of performing the
         copy.
 
         Items in the copy have an insertion/access order matching this
         instance.
         """
 
         capacity = capacity or self.capacity
         maxcost = maxcost or self.maxcost
         result = lrucachedict(capacity, maxcost=maxcost)
 
         # We copy entries by iterating in oldest-to-newest order so the copy
         # has the correct ordering.
 
         # Find the first non-empty entry.
         n = self._head.prev
         while n.key is _notset and n is not self._head:
             n = n.prev
 
         # We could potentially skip the first N items when decreasing capacity.
         # But let's keep it simple unless it is a performance problem.
         for i in range(len(self._cache)):
             result.insert(n.key, n.value, cost=n.cost)
             n = n.prev
 
         return result
 
     def popoldest(self):
         """Remove the oldest item from the cache.
 
         Returns the (key, value) describing the removed cache entry.
         """
         if not self._cache:
             return
 
         # Walk the linked list backwards starting at tail node until we hit
         # a non-empty node.
         n = self._head.prev
 
         assert n is not None  # help pytype
 
         while n.key is _notset:
             n = n.prev
 
         assert n is not None  # help pytype
 
         key, value = n.key, n.value
 
         # And remove it from the cache and mark it as empty.
         del self._cache[n.key]
         self.totalcost -= n.cost
         n.markempty()
 
         return key, value
 
     def _movetohead(self, node):
         """Mark a node as the newest, making it the new head.
 
         When a node is accessed, it becomes the freshest entry in the LRU
         list, which is denoted by self._head.
 
         Visually, let's make ``N`` the new head node (* denotes head):
 
             previous/oldest <-> head <-> next/next newest
 
             ----<->--- A* ---<->-----
             |                       |
             E <-> D <-> N <-> C <-> B
 
         To:
 
             ----<->--- N* ---<->-----
             |                       |
             E <-> D <-> C <-> B <-> A
 
         This requires the following moves:
 
            C.next = D  (node.prev.next = node.next)
            D.prev = C  (node.next.prev = node.prev)
            E.next = N  (head.prev.next = node)
            N.prev = E  (node.prev = head.prev)
            N.next = A  (node.next = head)
            A.prev = N  (head.prev = node)
         """
         head = self._head
         # C.next = D
         node.prev.next = node.next
         # D.prev = C
         node.next.prev = node.prev
         # N.prev = E
         node.prev = head.prev
         # N.next = A
         # It is tempting to do just "head" here, however if node is
         # adjacent to head, this will do bad things.
         node.next = head.prev.next
         # E.next = N
         node.next.prev = node
         # A.prev = N
         node.prev.next = node
 
         self._head = node
 
     def _addcapacity(self):
         """Add a node to the circular linked list.
 
         The new node is inserted before the head node.
         """
         head = self._head
         node = _lrucachenode()
         head.prev.next = node
         node.prev = head.prev
         node.next = head
         head.prev = node
         self._size += 1
         return node
 
     def _enforcecostlimit(self):
         # This should run after an insertion. It should only be called if total
         # cost limits are being enforced.
         # The most recently inserted node is never evicted.
         if len(self) <= 1 or self.totalcost <= self.maxcost:
             return
 
         # This is logically equivalent to calling popoldest() until we
         # free up enough cost. We don't do that since popoldest() needs
         # to walk the linked list and doing this in a loop would be
         # quadratic. So we find the first non-empty node and then
         # walk nodes until we free up enough capacity.
         #
         # If we only removed the minimum number of nodes to free enough
         # cost at insert time, chances are high that the next insert would
         # also require pruning. This would effectively constitute quadratic
         # behavior for insert-heavy workloads. To mitigate this, we set a
         # target cost that is a percentage of the max cost. This will tend
         # to free more nodes when the high water mark is reached, which
         # lowers the chances of needing to prune on the subsequent insert.
         targetcost = int(self.maxcost * 0.75)
 
         n = self._head.prev
         while n.key is _notset:
             n = n.prev
 
         while len(self) > 1 and self.totalcost > targetcost:
             del self._cache[n.key]
             self.totalcost -= n.cost
             n.markempty()
             n = n.prev
 
 
 def lrucachefunc(func):
     '''cache most recent results of function calls'''
     cache = {}
     order = collections.deque()
     if func.__code__.co_argcount == 1:
 
         def f(arg):
             if arg not in cache:
                 if len(cache) > 20:
                     del cache[order.popleft()]
                 cache[arg] = func(arg)
             else:
                 order.remove(arg)
             order.append(arg)
             return cache[arg]
 
     else:
 
         def f(*args):
             if args not in cache:
                 if len(cache) > 20:
                     del cache[order.popleft()]
                 cache[args] = func(*args)
             else:
                 order.remove(args)
             order.append(args)
             return cache[args]
 
     return f
 
 
 class propertycache:
     def __init__(self, func):
         self.func = func
         self.name = func.__name__
 
     def __get__(self, obj, type=None):
         result = self.func(obj)
         self.cachevalue(obj, result)
         return result
 
     def cachevalue(self, obj, value):
         # __dict__ assignment required to bypass __setattr__ (eg: repoview)
         obj.__dict__[self.name] = value
 
 
 def clearcachedproperty(obj, prop):
     '''clear a cached property value, if one has been set'''
     prop = pycompat.sysstr(prop)
     if prop in obj.__dict__:
         del obj.__dict__[prop]
 
 
 def increasingchunks(source, min=1024, max=65536):
     """return no less than min bytes per chunk while data remains,
     doubling min after each chunk until it reaches max"""
 
     def log2(x):
         if not x:
             return 0
         i = 0
         while x:
             x >>= 1
             i += 1
         return i - 1
 
     buf = []
     blen = 0
     for chunk in source:
         buf.append(chunk)
         blen += len(chunk)
         if blen >= min:
             if min < max:
                 min = min << 1
                 nmin = 1 << log2(blen)
                 if nmin > min:
                     min = nmin
                 if min > max:
                     min = max
             yield b''.join(buf)
             blen = 0
             buf = []
     if buf:
         yield b''.join(buf)
 
 
 def always(fn):
     return True
 
 
 def never(fn):
     return False
 
 
 def nogc(func):
     """disable garbage collector
 
     Python's garbage collector triggers a GC each time a certain number of
     container objects (the number being defined by gc.get_threshold()) are
     allocated even when marked not to be tracked by the collector. Tracking has
     no effect on when GCs are triggered, only on what objects the GC looks
     into. As a workaround, disable GC while building complex (huge)
     containers.
 
     This garbage collector issue have been fixed in 2.7. But it still affect
     CPython's performance.
     """
 
     def wrapper(*args, **kwargs):
         gcenabled = gc.isenabled()
         gc.disable()
         try:
             return func(*args, **kwargs)
         finally:
             if gcenabled:
                 gc.enable()
 
     return wrapper
 
 
 if pycompat.ispypy:
     # PyPy runs slower with gc disabled
     nogc = lambda x: x
 
 
 def pathto(root, n1, n2):
     # type: (bytes, bytes, bytes) -> bytes
     """return the relative path from one place to another.
     root should use os.sep to separate directories
     n1 should use os.sep to separate directories
     n2 should use "/" to separate directories
     returns an os.sep-separated path.
 
     If n1 is a relative path, it's assumed it's
     relative to root.
     n2 should always be relative to root.
     """
     if not n1:
         return localpath(n2)
     if os.path.isabs(n1):
         if os.path.splitdrive(root)[0] != os.path.splitdrive(n1)[0]:
             return os.path.join(root, localpath(n2))
         n2 = b'/'.join((pconvert(root), n2))
     a, b = splitpath(n1), n2.split(b'/')
     a.reverse()
     b.reverse()
     while a and b and a[-1] == b[-1]:
         a.pop()
         b.pop()
     b.reverse()
     return pycompat.ossep.join(([b'..'] * len(a)) + b) or b'.'
 
 
 def checksignature(func, depth=1):
     '''wrap a function with code to check for calling errors'''
 
     def check(*args, **kwargs):
         try:
             return func(*args, **kwargs)
         except TypeError:
             if len(traceback.extract_tb(sys.exc_info()[2])) == depth:
                 raise error.SignatureError
             raise
 
     return check
 
 
 # a whilelist of known filesystems where hardlink works reliably
 _hardlinkfswhitelist = {
     b'apfs',
     b'btrfs',
     b'ext2',
     b'ext3',
     b'ext4',
     b'hfs',
     b'jfs',
     b'NTFS',
     b'reiserfs',
     b'tmpfs',
     b'ufs',
     b'xfs',
     b'zfs',
 }
 
 
 def copyfile(
     src,
     dest,
     hardlink=False,
     copystat=False,
     checkambig=False,
     nb_bytes=None,
     no_hardlink_cb=None,
     check_fs_hardlink=True,
 ):
     """copy a file, preserving mode and optionally other stat info like
     atime/mtime
 
     checkambig argument is used with filestat, and is useful only if
     destination file is guarded by any lock (e.g. repo.lock or
     repo.wlock).
 
     copystat and checkambig should be exclusive.
 
     nb_bytes: if set only copy the first `nb_bytes` of the source file.
     """
     assert not (copystat and checkambig)
     oldstat = None
     if os.path.lexists(dest):
         if checkambig:
             oldstat = checkambig and filestat.frompath(dest)
         unlink(dest)
     if hardlink and check_fs_hardlink:
         # Hardlinks are problematic on CIFS (issue4546), do not allow hardlinks
         # unless we are confident that dest is on a whitelisted filesystem.
         try:
             fstype = getfstype(os.path.dirname(dest))
         except OSError:
             fstype = None
         if fstype not in _hardlinkfswhitelist:
             if no_hardlink_cb is not None:
                 no_hardlink_cb()
             hardlink = False
     if hardlink:
         try:
             oslink(src, dest)
             if nb_bytes is not None:
                 m = "the `nb_bytes` argument is incompatible with `hardlink`"
                 raise error.ProgrammingError(m)
             return
         except (IOError, OSError) as exc:
             if exc.errno != errno.EEXIST and no_hardlink_cb is not None:
                 no_hardlink_cb()
             # fall back to normal copy
     if os.path.islink(src):
         os.symlink(os.readlink(src), dest)
         # copytime is ignored for symlinks, but in general copytime isn't needed
         # for them anyway
         if nb_bytes is not None:
             m = "cannot use `nb_bytes` on a symlink"
             raise error.ProgrammingError(m)
     else:
         try:
             shutil.copyfile(src, dest)
             if copystat:
                 # copystat also copies mode
                 shutil.copystat(src, dest)
             else:
                 shutil.copymode(src, dest)
                 if oldstat and oldstat.stat:
                     newstat = filestat.frompath(dest)
                     if newstat.isambig(oldstat):
                         # stat of copied file is ambiguous to original one
                         advanced = (
                             oldstat.stat[stat.ST_MTIME] + 1
                         ) & 0x7FFFFFFF
                         os.utime(dest, (advanced, advanced))
             # We could do something smarter using `copy_file_range` call or similar
             if nb_bytes is not None:
                 with open(dest, mode='r+') as f:
                     f.truncate(nb_bytes)
         except shutil.Error as inst:
             raise error.Abort(stringutil.forcebytestr(inst))
 
 
 def copyfiles(src, dst, hardlink=None, progress=None):
     """Copy a directory tree using hardlinks if possible."""
     num = 0
 
     def settopic():
         if progress:
             progress.topic = _(b'linking') if hardlink else _(b'copying')
 
     if os.path.isdir(src):
         if hardlink is None:
             hardlink = (
                 os.stat(src).st_dev == os.stat(os.path.dirname(dst)).st_dev
             )
         settopic()
         os.mkdir(dst)
         for name, kind in listdir(src):
             srcname = os.path.join(src, name)
             dstname = os.path.join(dst, name)
             hardlink, n = copyfiles(srcname, dstname, hardlink, progress)
             num += n
     else:
         if hardlink is None:
             hardlink = (
                 os.stat(os.path.dirname(src)).st_dev
                 == os.stat(os.path.dirname(dst)).st_dev
             )
         settopic()
 
         if hardlink:
             try:
                 oslink(src, dst)
             except (IOError, OSError) as exc:
                 if exc.errno != errno.EEXIST:
                     hardlink = False
                 # XXX maybe try to relink if the file exist ?
                 shutil.copy(src, dst)
         else:
             shutil.copy(src, dst)
         num += 1
         if progress:
             progress.increment()
 
     return hardlink, num
 
 
 _winreservednames = {
     b'con',
     b'prn',
     b'aux',
     b'nul',
     b'com1',
     b'com2',
     b'com3',
     b'com4',
     b'com5',
     b'com6',
     b'com7',
     b'com8',
     b'com9',
     b'lpt1',
     b'lpt2',
     b'lpt3',
     b'lpt4',
     b'lpt5',
     b'lpt6',
     b'lpt7',
     b'lpt8',
     b'lpt9',
 }
 _winreservedchars = b':*?"<>|'
 
 
 def checkwinfilename(path):
     # type: (bytes) -> Optional[bytes]
     r"""Check that the base-relative path is a valid filename on Windows.
     Returns None if the path is ok, or a UI string describing the problem.
 
     >>> checkwinfilename(b"just/a/normal/path")
     >>> checkwinfilename(b"foo/bar/con.xml")
     "filename contains 'con', which is reserved on Windows"
     >>> checkwinfilename(b"foo/con.xml/bar")
     "filename contains 'con', which is reserved on Windows"
     >>> checkwinfilename(b"foo/bar/xml.con")
     >>> checkwinfilename(b"foo/bar/AUX/bla.txt")
     "filename contains 'AUX', which is reserved on Windows"
     >>> checkwinfilename(b"foo/bar/bla:.txt")
     "filename contains ':', which is reserved on Windows"
     >>> checkwinfilename(b"foo/bar/b\07la.txt")
     "filename contains '\\x07', which is invalid on Windows"
     >>> checkwinfilename(b"foo/bar/bla ")
     "filename ends with ' ', which is not allowed on Windows"
     >>> checkwinfilename(b"../bar")
     >>> checkwinfilename(b"foo\\")
     "filename ends with '\\', which is invalid on Windows"
     >>> checkwinfilename(b"foo\\/bar")
     "directory name ends with '\\', which is invalid on Windows"
     """
     if path.endswith(b'\\'):
         return _(b"filename ends with '\\', which is invalid on Windows")
     if b'\\/' in path:
         return _(b"directory name ends with '\\', which is invalid on Windows")
     for n in path.replace(b'\\', b'/').split(b'/'):
         if not n:
             continue
         for c in _filenamebytestr(n):
             if c in _winreservedchars:
                 return (
                     _(
                         b"filename contains '%s', which is reserved "
                         b"on Windows"
                     )
                     % c
                 )
             if ord(c) <= 31:
                 return _(
                     b"filename contains '%s', which is invalid on Windows"
                 ) % stringutil.escapestr(c)
         base = n.split(b'.')[0]
         if base and base.lower() in _winreservednames:
             return (
                 _(b"filename contains '%s', which is reserved on Windows")
                 % base
             )
         t = n[-1:]
         if t in b'. ' and n not in b'..':
             return (
                 _(
                     b"filename ends with '%s', which is not allowed "
                     b"on Windows"
                 )
                 % t
             )
 
 
 timer = getattr(time, "perf_counter", None)
 
 if pycompat.iswindows:
     checkosfilename = checkwinfilename
     if not timer:
         timer = time.clock
 else:
     # mercurial.windows doesn't have platform.checkosfilename
     checkosfilename = platform.checkosfilename  # pytype: disable=module-attr
     if not timer:
         timer = time.time
 
 
 def makelock(info, pathname):
     """Create a lock file atomically if possible
 
     This may leave a stale lock file if symlink isn't supported and signal
     interrupt is enabled.
     """
     try:
         return os.symlink(info, pathname)
     except OSError as why:
         if why.errno == errno.EEXIST:
             raise
     except AttributeError:  # no symlink in os
         pass
 
     flags = os.O_CREAT | os.O_WRONLY | os.O_EXCL | getattr(os, 'O_BINARY', 0)
     ld = os.open(pathname, flags)
     os.write(ld, info)
     os.close(ld)
 
 
 def readlock(pathname):
     # type: (bytes) -> bytes
     try:
         return readlink(pathname)
     except OSError as why:
         if why.errno not in (errno.EINVAL, errno.ENOSYS):
             raise
     except AttributeError:  # no symlink in os
         pass
     with posixfile(pathname, b'rb') as fp:
         return fp.read()
 
 
 def fstat(fp):
     '''stat file object that may not have fileno method.'''
     try:
         return os.fstat(fp.fileno())
     except AttributeError:
         return os.stat(fp.name)
 
 
 # File system features
 
 
 def fscasesensitive(path):
     # type: (bytes) -> bool
     """
     Return true if the given path is on a case-sensitive filesystem
 
     Requires a path (like /foo/.hg) ending with a foldable final
     directory component.
     """
     s1 = os.lstat(path)
     d, b = os.path.split(path)
     b2 = b.upper()
     if b == b2:
         b2 = b.lower()
         if b == b2:
             return True  # no evidence against case sensitivity
     p2 = os.path.join(d, b2)
     try:
         s2 = os.lstat(p2)
         if s2 == s1:
             return False
         return True
     except OSError:
         return True
 
 
 _re2_input = lambda x: x
 try:
     import re2  # pytype: disable=import-error
 
     _re2 = None
 except ImportError:
     _re2 = False
 
 
+def has_re2():
+    """return True is re2 is available, False otherwise"""
+    if _re2 is None:
+        _re._checkre2()
+    return _re2
+
+
 class _re:
     @staticmethod
     def _checkre2():
         global _re2
         global _re2_input
         if _re2 is not None:
             # we already have the answer
             return
 
         check_pattern = br'\[([^\[]+)\]'
         check_input = b'[ui]'
         try:
             # check if match works, see issue3964
             _re2 = bool(re2.match(check_pattern, check_input))
         except ImportError:
             _re2 = False
         except TypeError:
             # the `pyre-2` project provides a re2 module that accept bytes
             # the `fb-re2` project provides a re2 module that acccept sysstr
             check_pattern = pycompat.sysstr(check_pattern)
             check_input = pycompat.sysstr(check_input)
             _re2 = bool(re2.match(check_pattern, check_input))
             _re2_input = pycompat.sysstr
 
     def compile(self, pat, flags=0):
         """Compile a regular expression, using re2 if possible
 
         For best performance, use only re2-compatible regexp features. The
         only flags from the re module that are re2-compatible are
         IGNORECASE and MULTILINE."""
         if _re2 is None:
             self._checkre2()
         if _re2 and (flags & ~(remod.IGNORECASE | remod.MULTILINE)) == 0:
             if flags & remod.IGNORECASE:
                 pat = b'(?i)' + pat
             if flags & remod.MULTILINE:
                 pat = b'(?m)' + pat
             try:
                 return re2.compile(_re2_input(pat))
             except re2.error:
                 pass
         return remod.compile(pat, flags)
 
     @propertycache
     def escape(self):
         """Return the version of escape corresponding to self.compile.
 
         This is imperfect because whether re2 or re is used for a particular
         function depends on the flags, etc, but it's the best we can do.
         """
         global _re2
         if _re2 is None:
             self._checkre2()
         if _re2:
             return re2.escape
         else:
             return remod.escape
 
 
 re = _re()
 
 _fspathcache = {}
 
 
 def fspath(name, root):
     # type: (bytes, bytes) -> bytes
     """Get name in the case stored in the filesystem
 
     The name should be relative to root, and be normcase-ed for efficiency.
 
     Note that this function is unnecessary, and should not be
     called, for case-sensitive filesystems (simply because it's expensive).
 
     The root should be normcase-ed, too.
     """
 
     def _makefspathcacheentry(dir):
         return {normcase(n): n for n in os.listdir(dir)}
 
     seps = pycompat.ossep
     if pycompat.osaltsep:
         seps = seps + pycompat.osaltsep
     # Protect backslashes. This gets silly very quickly.
     seps.replace(b'\\', b'\\\\')
     pattern = remod.compile(br'([^%s]+)|([%s]+)' % (seps, seps))
     dir = os.path.normpath(root)
     result = []
     for part, sep in pattern.findall(name):
         if sep:
             result.append(sep)
             continue
 
         if dir not in _fspathcache:
             _fspathcache[dir] = _makefspathcacheentry(dir)
         contents = _fspathcache[dir]
 
         found = contents.get(part)
         if not found:
             # retry "once per directory" per "dirstate.walk" which
             # may take place for each patches of "hg qpush", for example
             _fspathcache[dir] = contents = _makefspathcacheentry(dir)
             found = contents.get(part)
 
         result.append(found or part)
         dir = os.path.join(dir, part)
 
     return b''.join(result)
 
 
 def checknlink(testfile):
     # type: (bytes) -> bool
     '''check whether hardlink count reporting works properly'''
 
     # testfile may be open, so we need a separate file for checking to
     # work around issue2543 (or testfile may get lost on Samba shares)
     f1, f2, fp = None, None, None
     try:
         fd, f1 = pycompat.mkstemp(
             prefix=b'.%s-' % os.path.basename(testfile),
             suffix=b'1~',
             dir=os.path.dirname(testfile),
         )
         os.close(fd)
         f2 = b'%s2~' % f1[:-2]
 
         oslink(f1, f2)
         # nlinks() may behave differently for files on Windows shares if
         # the file is open.
         fp = posixfile(f2)
         return nlinks(f2) > 1
     except OSError:
         return False
     finally:
         if fp is not None:
             fp.close()
         for f in (f1, f2):
             try:
                 if f is not None:
                     os.unlink(f)
             except OSError:
                 pass
 
 
 def endswithsep(path):
     # type: (bytes) -> bool
     '''Check path ends with os.sep or os.altsep.'''
     return bool(  # help pytype
         path.endswith(pycompat.ossep)
         or pycompat.osaltsep
         and path.endswith(pycompat.osaltsep)
     )
 
 
 def splitpath(path):
     # type: (bytes) -> List[bytes]
     """Split path by os.sep.
     Note that this function does not use os.altsep because this is
     an alternative of simple "xxx.split(os.sep)".
     It is recommended to use os.path.normpath() before using this
     function if need."""
     return path.split(pycompat.ossep)
 
 
 def mktempcopy(name, emptyok=False, createmode=None, enforcewritable=False):
     """Create a temporary file with the same contents from name
 
     The permission bits are copied from the original file.
 
     If the temporary file is going to be truncated immediately, you
     can use emptyok=True as an optimization.
 
     Returns the name of the temporary file.
     """
     d, fn = os.path.split(name)
     fd, temp = pycompat.mkstemp(prefix=b'.%s-' % fn, suffix=b'~', dir=d)
     os.close(fd)
     # Temporary files are created with mode 0600, which is usually not
     # what we want.  If the original file already exists, just copy
     # its mode.  Otherwise, manually obey umask.
     copymode(name, temp, createmode, enforcewritable)
 
     if emptyok:
         return temp
     try:
         try:
             ifp = posixfile(name, b"rb")
         except IOError as inst:
             if inst.errno == errno.ENOENT:
                 return temp
             if not getattr(inst, 'filename', None):
                 inst.filename = name
             raise
         ofp = posixfile(temp, b"wb")
         for chunk in filechunkiter(ifp):
             ofp.write(chunk)
         ifp.close()
         ofp.close()
     except:  # re-raises
         try:
             os.unlink(temp)
         except OSError:
             pass
         raise
     return temp
 
 
 class filestat:
     """help to exactly detect change of a file
 
     'stat' attribute is result of 'os.stat()' if specified 'path'
     exists. Otherwise, it is None. This can avoid preparative
     'exists()' examination on client side of this class.
     """
 
     def __init__(self, stat):
         self.stat = stat
 
     @classmethod
     def frompath(cls, path):
         try:
             stat = os.stat(path)
         except FileNotFoundError:
             stat = None
         return cls(stat)
 
     @classmethod
     def fromfp(cls, fp):
         stat = os.fstat(fp.fileno())
         return cls(stat)
 
     __hash__ = object.__hash__
 
     def __eq__(self, old):
         try:
             # if ambiguity between stat of new and old file is
             # avoided, comparison of size, ctime and mtime is enough
             # to exactly detect change of a file regardless of platform
             return (
                 self.stat.st_size == old.stat.st_size
                 and self.stat[stat.ST_CTIME] == old.stat[stat.ST_CTIME]
                 and self.stat[stat.ST_MTIME] == old.stat[stat.ST_MTIME]
             )
         except AttributeError:
             pass
         try:
             return self.stat is None and old.stat is None
         except AttributeError:
             return False
 
     def isambig(self, old):
         """Examine whether new (= self) stat is ambiguous against old one
 
         "S[N]" below means stat of a file at N-th change:
 
         - S[n-1].ctime  < S[n].ctime: can detect change of a file
         - S[n-1].ctime == S[n].ctime
           - S[n-1].ctime  < S[n].mtime: means natural advancing (*1)
           - S[n-1].ctime == S[n].mtime: is ambiguous (*2)
           - S[n-1].ctime  > S[n].mtime: never occurs naturally (don't care)
         - S[n-1].ctime  > S[n].ctime: never occurs naturally (don't care)
 
         Case (*2) above means that a file was changed twice or more at
         same time in sec (= S[n-1].ctime), and comparison of timestamp
         is ambiguous.
 
         Base idea to avoid such ambiguity is "advance mtime 1 sec, if
         timestamp is ambiguous".
 
         But advancing mtime only in case (*2) doesn't work as
         expected, because naturally advanced S[n].mtime in case (*1)
         might be equal to manually advanced S[n-1 or earlier].mtime.
 
         Therefore, all "S[n-1].ctime == S[n].ctime" cases should be
         treated as ambiguous regardless of mtime, to avoid overlooking
         by confliction between such mtime.
 
         Advancing mtime "if isambig(oldstat)" ensures "S[n-1].mtime !=
         S[n].mtime", even if size of a file isn't changed.
         """
         try:
             return self.stat[stat.ST_CTIME] == old.stat[stat.ST_CTIME]
         except AttributeError:
             return False
 
     def avoidambig(self, path, old):
         """Change file stat of specified path to avoid ambiguity
 
         'old' should be previous filestat of 'path'.
 
         This skips avoiding ambiguity, if a process doesn't have
         appropriate privileges for 'path'. This returns False in this
         case.
 
         Otherwise, this returns True, as "ambiguity is avoided".
         """
         advanced = (old.stat[stat.ST_MTIME] + 1) & 0x7FFFFFFF
         try:
             os.utime(path, (advanced, advanced))
         except PermissionError:
             # utime() on the file created by another user causes EPERM,
             # if a process doesn't have appropriate privileges
             return False
         return True
 
     def __ne__(self, other):
         return not self == other
 
 
 class atomictempfile:
     """writable file object that atomically updates a file
 
     All writes will go to a temporary copy of the original file. Call
     close() when you are done writing, and atomictempfile will rename
     the temporary copy to the original name, making the changes
     visible. If the object is destroyed without being closed, all your
     writes are discarded.
 
     checkambig argument of constructor is used with filestat, and is
     useful only if target file is guarded by any lock (e.g. repo.lock
     or repo.wlock).
     """
 
     def __init__(self, name, mode=b'w+b', createmode=None, checkambig=False):
         self.__name = name  # permanent name
         self._tempname = mktempcopy(
             name,
             emptyok=(b'w' in mode),
             createmode=createmode,
             enforcewritable=(b'w' in mode),
         )
 
         self._fp = posixfile(self._tempname, mode)
         self._checkambig = checkambig
 
         # delegated methods
         self.read = self._fp.read
         self.write = self._fp.write
         self.writelines = self._fp.writelines
         self.seek = self._fp.seek
         self.tell = self._fp.tell
         self.fileno = self._fp.fileno
 
     def close(self):
         if not self._fp.closed:
             self._fp.close()
             filename = localpath(self.__name)
             oldstat = self._checkambig and filestat.frompath(filename)
             if oldstat and oldstat.stat:
                 rename(self._tempname, filename)
                 newstat = filestat.frompath(filename)
                 if newstat.isambig(oldstat):
                     # stat of changed file is ambiguous to original one
                     advanced = (oldstat.stat[stat.ST_MTIME] + 1) & 0x7FFFFFFF
                     os.utime(filename, (advanced, advanced))
             else:
                 rename(self._tempname, filename)
 
     def discard(self):
         if not self._fp.closed:
             try:
                 os.unlink(self._tempname)
             except OSError:
                 pass
             self._fp.close()
 
     def __del__(self):
         if safehasattr(self, '_fp'):  # constructor actually did something
             self.discard()
 
     def __enter__(self):
         return self
 
     def __exit__(self, exctype, excvalue, traceback):
         if exctype is not None:
             self.discard()
         else:
             self.close()
 
 
 def tryrmdir(f):
     try:
         removedirs(f)
     except OSError as e:
         if e.errno != errno.ENOENT and e.errno != errno.ENOTEMPTY:
             raise
 
 
 def unlinkpath(f, ignoremissing=False, rmdir=True):
     # type: (bytes, bool, bool) -> None
     """unlink and remove the directory if it is empty"""
     if ignoremissing:
         tryunlink(f)
     else:
         unlink(f)
     if rmdir:
         # try removing directories that might now be empty
         try:
             removedirs(os.path.dirname(f))
         except OSError:
             pass
 
 
 def tryunlink(f):
     # type: (bytes) -> None
     """Attempt to remove a file, ignoring FileNotFoundError."""
     try:
         unlink(f)
     except FileNotFoundError:
         pass
 
 
 def makedirs(name, mode=None, notindexed=False):
     # type: (bytes, Optional[int], bool) -> None
     """recursive directory creation with parent mode inheritance
 
     Newly created directories are marked as "not to be indexed by
     the content indexing service", if ``notindexed`` is specified
     for "write" mode access.
     """
     try:
         makedir(name, notindexed)
     except OSError as err:
         if err.errno == errno.EEXIST:
             return
         if err.errno != errno.ENOENT or not name:
             raise
         parent = os.path.dirname(abspath(name))
         if parent == name:
             raise
         makedirs(parent, mode, notindexed)
         try:
             makedir(name, notindexed)
         except OSError as err:
             # Catch EEXIST to handle races
             if err.errno == errno.EEXIST:
                 return
             raise
     if mode is not None:
         os.chmod(name, mode)
 
 
 def readfile(path):
     # type: (bytes) -> bytes
     with open(path, b'rb') as fp:
         return fp.read()
 
 
 def writefile(path, text):
     # type: (bytes, bytes) -> None
     with open(path, b'wb') as fp:
         fp.write(text)
 
 
 def appendfile(path, text):
     # type: (bytes, bytes) -> None
     with open(path, b'ab') as fp:
         fp.write(text)
 
 
 class chunkbuffer:
     """Allow arbitrary sized chunks of data to be efficiently read from an
     iterator over chunks of arbitrary size."""
 
     def __init__(self, in_iter):
         """in_iter is the iterator that's iterating over the input chunks."""
 
         def splitbig(chunks):
             for chunk in chunks:
                 if len(chunk) > 2 ** 20:
                     pos = 0
                     while pos < len(chunk):
                         end = pos + 2 ** 18
                         yield chunk[pos:end]
                         pos = end
                 else:
                     yield chunk
 
         self.iter = splitbig(in_iter)
         self._queue = collections.deque()
         self._chunkoffset = 0
 
     def read(self, l=None):
         """Read L bytes of data from the iterator of chunks of data.
         Returns less than L bytes if the iterator runs dry.
 
         If size parameter is omitted, read everything"""
         if l is None:
             return b''.join(self.iter)
 
         left = l
         buf = []
         queue = self._queue
         while left > 0:
             # refill the queue
             if not queue:
                 target = 2 ** 18
                 for chunk in self.iter:
                     queue.append(chunk)
                     target -= len(chunk)
                     if target <= 0:
                         break
                 if not queue:
                     break
 
             # The easy way to do this would be to queue.popleft(), modify the
             # chunk (if necessary), then queue.appendleft(). However, for cases
             # where we read partial chunk content, this incurs 2 dequeue
             # mutations and creates a new str for the remaining chunk in the
             # queue. Our code below avoids this overhead.
 
             chunk = queue[0]
             chunkl = len(chunk)
             offset = self._chunkoffset
 
             # Use full chunk.
             if offset == 0 and left >= chunkl:
                 left -= chunkl
                 queue.popleft()
                 buf.append(chunk)
                 # self._chunkoffset remains at 0.
                 continue
 
             chunkremaining = chunkl - offset
 
             # Use all of unconsumed part of chunk.
             if left >= chunkremaining:
                 left -= chunkremaining
                 queue.popleft()
                 # offset == 0 is enabled by block above, so this won't merely
                 # copy via ``chunk[0:]``.
                 buf.append(chunk[offset:])
                 self._chunkoffset = 0
 
             # Partial chunk needed.
             else:
                 buf.append(chunk[offset : offset + left])
                 self._chunkoffset += left
                 left -= chunkremaining
 
         return b''.join(buf)
 
 
 def filechunkiter(f, size=131072, limit=None):
     """Create a generator that produces the data in the file size
     (default 131072) bytes at a time, up to optional limit (default is
     to read all data).  Chunks may be less than size bytes if the
     chunk is the last chunk in the file, or the file is a socket or
     some other type of file that sometimes reads less data than is
     requested."""
     assert size >= 0
     assert limit is None or limit >= 0
     while True:
         if limit is None:
             nbytes = size
         else:
             nbytes = min(limit, size)
         s = nbytes and f.read(nbytes)
         if not s:
             break
         if limit:
             limit -= len(s)
         yield s
 
 
 class cappedreader:
     """A file object proxy that allows reading up to N bytes.
 
     Given a source file object, instances of this type allow reading up to
     N bytes from that source file object. Attempts to read past the allowed
     limit are treated as EOF.
 
     It is assumed that I/O is not performed on the original file object
     in addition to I/O that is performed by this instance. If there is,
     state tracking will get out of sync and unexpected results will ensue.
     """
 
     def __init__(self, fh, limit):
         """Allow reading up to <limit> bytes from <fh>."""
         self._fh = fh
         self._left = limit
 
     def read(self, n=-1):
         if not self._left:
             return b''
 
         if n < 0:
             n = self._left
 
         data = self._fh.read(min(n, self._left))
         self._left -= len(data)
         assert self._left >= 0
 
         return data
 
     def readinto(self, b):
         res = self.read(len(b))
         if res is None:
             return None
 
         b[0 : len(res)] = res
         return len(res)
 
 
 def unitcountfn(*unittable):
     '''return a function that renders a readable count of some quantity'''
 
     def go(count):
         for multiplier, divisor, format in unittable:
             if abs(count) >= divisor * multiplier:
                 return format % (count / float(divisor))
         return unittable[-1][2] % count
 
     return go
 
 
 def processlinerange(fromline, toline):
     # type: (int, int) -> Tuple[int, int]
     """Check that linerange <fromline>:<toline> makes sense and return a
     0-based range.
 
     >>> processlinerange(10, 20)
     (9, 20)
     >>> processlinerange(2, 1)
     Traceback (most recent call last):
         ...
     ParseError: line range must be positive
     >>> processlinerange(0, 5)
     Traceback (most recent call last):
         ...
     ParseError: fromline must be strictly positive
     """
     if toline - fromline < 0:
         raise error.ParseError(_(b"line range must be positive"))
     if fromline < 1:
         raise error.ParseError(_(b"fromline must be strictly positive"))
     return fromline - 1, toline
 
 
 bytecount = unitcountfn(
     (100, 1 << 30, _(b'%.0f GB')),
     (10, 1 << 30, _(b'%.1f GB')),
     (1, 1 << 30, _(b'%.2f GB')),
     (100, 1 << 20, _(b'%.0f MB')),
     (10, 1 << 20, _(b'%.1f MB')),
     (1, 1 << 20, _(b'%.2f MB')),
     (100, 1 << 10, _(b'%.0f KB')),
     (10, 1 << 10, _(b'%.1f KB')),
     (1, 1 << 10, _(b'%.2f KB')),
     (1, 1, _(b'%.0f bytes')),
 )
 
 
 class transformingwriter:
     """Writable file wrapper to transform data by function"""
 
     def __init__(self, fp, encode):
         self._fp = fp
         self._encode = encode
 
     def close(self):
         self._fp.close()
 
     def flush(self):
         self._fp.flush()
 
     def write(self, data):
         return self._fp.write(self._encode(data))
 
 
 # Matches a single EOL which can either be a CRLF where repeated CR
 # are removed or a LF. We do not care about old Macintosh files, so a
 # stray CR is an error.
 _eolre = remod.compile(br'\r*\n')
 
 
 def tolf(s):
     # type: (bytes) -> bytes
     return _eolre.sub(b'\n', s)
 
 
 def tocrlf(s):
     # type: (bytes) -> bytes
     return _eolre.sub(b'\r\n', s)
 
 
 def _crlfwriter(fp):
     return transformingwriter(fp, tocrlf)
 
 
 if pycompat.oslinesep == b'\r\n':
     tonativeeol = tocrlf
     fromnativeeol = tolf
     nativeeolwriter = _crlfwriter
 else:
     tonativeeol = pycompat.identity
     fromnativeeol = pycompat.identity
     nativeeolwriter = pycompat.identity
 
 
 # TODO delete since workaround variant for Python 2 no longer needed.
 def iterfile(fp):
     return fp
 
 
 def iterlines(iterator):
     # type: (Iterable[bytes]) -> Iterator[bytes]
     for chunk in iterator:
         for line in chunk.splitlines():
             yield line
 
 
 def expandpath(path):
     # type: (bytes) -> bytes
     return os.path.expanduser(os.path.expandvars(path))
 
 
 def interpolate(prefix, mapping, s, fn=None, escape_prefix=False):
     """Return the result of interpolating items in the mapping into string s.
 
     prefix is a single character string, or a two character string with
     a backslash as the first character if the prefix needs to be escaped in
     a regular expression.
 
     fn is an optional function that will be applied to the replacement text
     just before replacement.
 
     escape_prefix is an optional flag that allows using doubled prefix for
     its escaping.
     """
     fn = fn or (lambda s: s)
     patterns = b'|'.join(mapping.keys())
     if escape_prefix:
         patterns += b'|' + prefix
         if len(prefix) > 1:
             prefix_char = prefix[1:]
         else:
             prefix_char = prefix
         mapping[prefix_char] = prefix_char
     r = remod.compile(br'%s(%s)' % (prefix, patterns))
     return r.sub(lambda x: fn(mapping[x.group()[1:]]), s)
 
 
 timecount = unitcountfn(
     (1, 1e3, _(b'%.0f s')),
     (100, 1, _(b'%.1f s')),
     (10, 1, _(b'%.2f s')),
     (1, 1, _(b'%.3f s')),
     (100, 0.001, _(b'%.1f ms')),
     (10, 0.001, _(b'%.2f ms')),
     (1, 0.001, _(b'%.3f ms')),
     (100, 0.000001, _(b'%.1f us')),
     (10, 0.000001, _(b'%.2f us')),
     (1, 0.000001, _(b'%.3f us')),
     (100, 0.000000001, _(b'%.1f ns')),
     (10, 0.000000001, _(b'%.2f ns')),
     (1, 0.000000001, _(b'%.3f ns')),
 )
 
 
 @attr.s
 class timedcmstats:
     """Stats information produced by the timedcm context manager on entering."""
 
     # the starting value of the timer as a float (meaning and resulution is
     # platform dependent, see util.timer)
     start = attr.ib(default=attr.Factory(lambda: timer()))
     # the number of seconds as a floating point value; starts at 0, updated when
     # the context is exited.
     elapsed = attr.ib(default=0)
     # the number of nested timedcm context managers.
     level = attr.ib(default=1)
 
     def __bytes__(self):
         return timecount(self.elapsed) if self.elapsed else b'<unknown>'
 
     __str__ = encoding.strmethod(__bytes__)
 
 
 @contextlib.contextmanager
 def timedcm(whencefmt, *whenceargs):
     """A context manager that produces timing information for a given context.
 
     On entering a timedcmstats instance is produced.
 
     This context manager is reentrant.
 
     """
     # track nested context managers
     timedcm._nested += 1
     timing_stats = timedcmstats(level=timedcm._nested)
     try:
         with tracing.log(whencefmt, *whenceargs):
             yield timing_stats
     finally:
         timing_stats.elapsed = timer() - timing_stats.start
         timedcm._nested -= 1
 
 
 timedcm._nested = 0
 
 
 def timed(func):
     """Report the execution time of a function call to stderr.
 
     During development, use as a decorator when you need to measure
     the cost of a function, e.g. as follows:
 
     @util.timed
     def foo(a, b, c):
         pass
     """
 
     def wrapper(*args, **kwargs):
         with timedcm(pycompat.bytestr(func.__name__)) as time_stats:
             result = func(*args, **kwargs)
         stderr = procutil.stderr
         stderr.write(
             b'%s%s: %s\n'
             % (
                 b' ' * time_stats.level * 2,
                 pycompat.bytestr(func.__name__),
                 time_stats,
             )
         )
         return result
 
     return wrapper
 
 
 _sizeunits = (
     (b'm', 2 ** 20),
     (b'k', 2 ** 10),
     (b'g', 2 ** 30),
     (b'kb', 2 ** 10),
     (b'mb', 2 ** 20),
     (b'gb', 2 ** 30),
     (b'b', 1),
 )
 
 
 def sizetoint(s):
     # type: (bytes) -> int
     """Convert a space specifier to a byte count.
 
     >>> sizetoint(b'30')
     30
     >>> sizetoint(b'2.2kb')
     2252
     >>> sizetoint(b'6M')
     6291456
     """
     t = s.strip().lower()
     try:
         for k, u in _sizeunits:
             if t.endswith(k):
                 return int(float(t[: -len(k)]) * u)
         return int(t)
     except ValueError:
         raise error.ParseError(_(b"couldn't parse size: %s") % s)
 
 
 class hooks:
     """A collection of hook functions that can be used to extend a
     function's behavior. Hooks are called in lexicographic order,
     based on the names of their sources."""
 
     def __init__(self):
         self._hooks = []
 
     def add(self, source, hook):
         self._hooks.append((source, hook))
 
     def __call__(self, *args):
         self._hooks.sort(key=lambda x: x[0])
         results = []
         for source, hook in self._hooks:
             results.append(hook(*args))
         return results
 
 
 def getstackframes(skip=0, line=b' %-*s in %s\n', fileline=b'%s:%d', depth=0):
     """Yields lines for a nicely formatted stacktrace.
     Skips the 'skip' last entries, then return the last 'depth' entries.
     Each file+linenumber is formatted according to fileline.
     Each line is formatted according to line.
     If line is None, it yields:
       length of longest filepath+line number,
       filepath+linenumber,
       function
 
     Not be used in production code but very convenient while developing.
     """
     entries = [
         (fileline % (pycompat.sysbytes(fn), ln), pycompat.sysbytes(func))
         for fn, ln, func, _text in traceback.extract_stack()[: -skip - 1]
     ][-depth:]
     if entries:
         fnmax = max(len(entry[0]) for entry in entries)
         for fnln, func in entries:
             if line is None:
                 yield (fnmax, fnln, func)
             else:
                 yield line % (fnmax, fnln, func)
 
 
 def debugstacktrace(
     msg=b'stacktrace',
     skip=0,
     f=procutil.stderr,
     otherf=procutil.stdout,
     depth=0,
     prefix=b'',
 ):
     """Writes a message to f (stderr) with a nicely formatted stacktrace.
     Skips the 'skip' entries closest to the call, then show 'depth' entries.
     By default it will flush stdout first.
     It can be used everywhere and intentionally does not require an ui object.
     Not be used in production code but very convenient while developing.
     """
     if otherf:
         otherf.flush()
     f.write(b'%s%s at:\n' % (prefix, msg.rstrip()))
     for line in getstackframes(skip + 1, depth=depth):
         f.write(prefix + line)
     f.flush()
 
 
 # convenient shortcut
 dst = debugstacktrace
 
 
 def safename(f, tag, ctx, others=None):
     """
     Generate a name that it is safe to rename f to in the given context.
 
     f:      filename to rename
     tag:    a string tag that will be included in the new name
     ctx:    a context, in which the new name must not exist
     others: a set of other filenames that the new name must not be in
 
     Returns a file name of the form oldname~tag[~number] which does not exist
     in the provided context and is not in the set of other names.
     """
     if others is None:
         others = set()
 
     fn = b'%s~%s' % (f, tag)
     if fn not in ctx and fn not in others:
         return fn
     for n in itertools.count(1):
         fn = b'%s~%s~%s' % (f, tag, n)
         if fn not in ctx and fn not in others:
             return fn
 
 
 def readexactly(stream, n):
     '''read n bytes from stream.read and abort if less was available'''
     s = stream.read(n)
     if len(s) < n:
         raise error.Abort(
             _(b"stream ended unexpectedly (got %d bytes, expected %d)")
             % (len(s), n)
         )
     return s
 
 
 def uvarintencode(value):
     """Encode an unsigned integer value to a varint.
 
     A varint is a variable length integer of 1 or more bytes. Each byte
     except the last has the most significant bit set. The lower 7 bits of
     each byte store the 2's complement representation, least significant group
     first.
 
     >>> uvarintencode(0)
     '\\x00'
     >>> uvarintencode(1)
     '\\x01'
     >>> uvarintencode(127)
     '\\x7f'
     >>> uvarintencode(1337)
     '\\xb9\\n'
     >>> uvarintencode(65536)
     '\\x80\\x80\\x04'
     >>> uvarintencode(-1)
     Traceback (most recent call last):
         ...
     ProgrammingError: negative value for uvarint: -1
     """
     if value < 0:
         raise error.ProgrammingError(b'negative value for uvarint: %d' % value)
     bits = value & 0x7F
     value >>= 7
     bytes = []
     while value:
         bytes.append(pycompat.bytechr(0x80 | bits))
         bits = value & 0x7F
         value >>= 7
     bytes.append(pycompat.bytechr(bits))
 
     return b''.join(bytes)
 
 
 def uvarintdecodestream(fh):
     """Decode an unsigned variable length integer from a stream.
 
     The passed argument is anything that has a ``.read(N)`` method.
 
     >>> from io import BytesIO
     >>> uvarintdecodestream(BytesIO(b'\\x00'))
     0
     >>> uvarintdecodestream(BytesIO(b'\\x01'))
     1
     >>> uvarintdecodestream(BytesIO(b'\\x7f'))
     127
     >>> uvarintdecodestream(BytesIO(b'\\xb9\\n'))
     1337
     >>> uvarintdecodestream(BytesIO(b'\\x80\\x80\\x04'))
     65536
     >>> uvarintdecodestream(BytesIO(b'\\x80'))
     Traceback (most recent call last):
         ...
     Abort: stream ended unexpectedly (got 0 bytes, expected 1)
     """
     result = 0
     shift = 0
     while True:
         byte = ord(readexactly(fh, 1))
         result |= (byte & 0x7F) << shift
         if not (byte & 0x80):
             return result
         shift += 7
 
 
 # Passing the '' locale means that the locale should be set according to the
 # user settings (environment variables).
 # Python sometimes avoids setting the global locale settings. When interfacing
 # with C code (e.g. the curses module or the Subversion bindings), the global
 # locale settings must be initialized correctly. Python 2 does not initialize
 # the global locale settings on interpreter startup. Python 3 sometimes
 # initializes LC_CTYPE, but not consistently at least on Windows. Therefore we
 # explicitly initialize it to get consistent behavior if it's not already
 # initialized. Since CPython commit 177d921c8c03d30daa32994362023f777624b10d,
 # LC_CTYPE is always initialized. If we require Python 3.8+, we should re-check
 # if we can remove this code.
 @contextlib.contextmanager
 def with_lc_ctype():
     oldloc = locale.setlocale(locale.LC_CTYPE, None)
     if oldloc == 'C':
         try:
             try:
                 locale.setlocale(locale.LC_CTYPE, '')
             except locale.Error:
                 # The likely case is that the locale from the environment
                 # variables is unknown.
                 pass
             yield
         finally:
             locale.setlocale(locale.LC_CTYPE, oldloc)
     else:
         yield
 
 
 def _estimatememory():
     # type: () -> Optional[int]
     """Provide an estimate for the available system memory in Bytes.
 
     If no estimate can be provided on the platform, returns None.
     """
     if pycompat.sysplatform.startswith(b'win'):
         # On Windows, use the GlobalMemoryStatusEx kernel function directly.
         from ctypes import c_long as DWORD, c_ulonglong as DWORDLONG
         from ctypes.wintypes import (  # pytype: disable=import-error
             Structure,
             byref,
             sizeof,
             windll,
         )
 
         class MEMORYSTATUSEX(Structure):
             _fields_ = [
                 ('dwLength', DWORD),
                 ('dwMemoryLoad', DWORD),
                 ('ullTotalPhys', DWORDLONG),
                 ('ullAvailPhys', DWORDLONG),
                 ('ullTotalPageFile', DWORDLONG),
                 ('ullAvailPageFile', DWORDLONG),
                 ('ullTotalVirtual', DWORDLONG),
                 ('ullAvailVirtual', DWORDLONG),
                 ('ullExtendedVirtual', DWORDLONG),
             ]
 
         x = MEMORYSTATUSEX()
         x.dwLength = sizeof(x)
         windll.kernel32.GlobalMemoryStatusEx(byref(x))
         return x.ullAvailPhys
 
     # On newer Unix-like systems and Mac OSX, the sysconf interface
     # can be used. _SC_PAGE_SIZE is part of POSIX; _SC_PHYS_PAGES
     # seems to be implemented on most systems.
     try:
         pagesize = os.sysconf(os.sysconf_names['SC_PAGE_SIZE'])
         pages = os.sysconf(os.sysconf_names['SC_PHYS_PAGES'])
         return pagesize * pages
     except OSError:  # sysconf can fail
         pass
     except KeyError:  # unknown parameter
         pass