progress: create helper class for incrementing progress

When using ui.progress(), there's a clear pattern that is followed:

 * Pass the same topic and unit
 * Usually pass the same total
 * Call with pos=None to close the progress bar
 * Often keep track of the current position and increment it

This patch creates a simple helper class for this. I'll probably make
it implement the context manager protocol later (calling update(None)
on __exit__).

Progress is used in low-level modules like changegroup, so I also
exposed it via a method on the ui object. Perhaps the class itself
should also live in ui.py?

This patch also makes merge.oy use it to show that it works.

Differential Revision: https://phab.mercurial-scm.org/D3765

mercurial/merge.py

@@ -1,2247 +1,2232 b''
 # merge.py - directory-level update/merge handling for Mercurial
 #
 # Copyright 2006, 2007 Matt 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.
 
 from __future__ import absolute_import
 
 import errno
 import hashlib
 import shutil
 import struct
 
 from .i18n import _
 from .node import (
     addednodeid,
     bin,
     hex,
     modifiednodeid,
     nullhex,
     nullid,
     nullrev,
 )
 from .thirdparty import (
     attr,
 )
 from . import (
     copies,
     error,
     filemerge,
     match as matchmod,
     obsutil,
     pycompat,
     scmutil,
     subrepoutil,
     util,
     worker,
 )
 
 _pack = struct.pack
 _unpack = struct.unpack
 
 def _droponode(data):
     # used for compatibility for v1
     bits = data.split('\0')
     bits = bits[:-2] + bits[-1:]
     return '\0'.join(bits)
 
 # Merge state record types. See ``mergestate`` docs for more.
 RECORD_LOCAL = b'L'
 RECORD_OTHER = b'O'
 RECORD_MERGED = b'F'
 RECORD_CHANGEDELETE_CONFLICT = b'C'
 RECORD_MERGE_DRIVER_MERGE = b'D'
 RECORD_PATH_CONFLICT = b'P'
 RECORD_MERGE_DRIVER_STATE = b'm'
 RECORD_FILE_VALUES = b'f'
 RECORD_LABELS = b'l'
 RECORD_OVERRIDE = b't'
 RECORD_UNSUPPORTED_MANDATORY = b'X'
 RECORD_UNSUPPORTED_ADVISORY = b'x'
 
 MERGE_DRIVER_STATE_UNMARKED = b'u'
 MERGE_DRIVER_STATE_MARKED = b'm'
 MERGE_DRIVER_STATE_SUCCESS = b's'
 
 MERGE_RECORD_UNRESOLVED = b'u'
 MERGE_RECORD_RESOLVED = b'r'
 MERGE_RECORD_UNRESOLVED_PATH = b'pu'
 MERGE_RECORD_RESOLVED_PATH = b'pr'
 MERGE_RECORD_DRIVER_RESOLVED = b'd'
 
 ACTION_FORGET = b'f'
 ACTION_REMOVE = b'r'
 ACTION_ADD = b'a'
 ACTION_GET = b'g'
 ACTION_PATH_CONFLICT = b'p'
 ACTION_PATH_CONFLICT_RESOLVE = b'pr'
 ACTION_ADD_MODIFIED = b'am'
 ACTION_CREATED = b'c'
 ACTION_DELETED_CHANGED = b'dc'
 ACTION_CHANGED_DELETED = b'cd'
 ACTION_MERGE = b'm'
 ACTION_LOCAL_DIR_RENAME_GET = b'dg'
 ACTION_DIR_RENAME_MOVE_LOCAL = b'dm'
 ACTION_KEEP = b'k'
 ACTION_EXEC = b'e'
 ACTION_CREATED_MERGE = b'cm'
 
 class mergestate(object):
     '''track 3-way merge state of individual files
 
     The merge state is stored on disk when needed. Two files are used: one with
     an old format (version 1), and one with a new format (version 2). Version 2
     stores a superset of the data in version 1, including new kinds of records
     in the future. For more about the new format, see the documentation for
     `_readrecordsv2`.
 
     Each record can contain arbitrary content, and has an associated type. This
     `type` should be a letter. If `type` is uppercase, the record is mandatory:
     versions of Mercurial that don't support it should abort. If `type` is
     lowercase, the record can be safely ignored.
 
     Currently known records:
 
     L: the node of the "local" part of the merge (hexified version)
     O: the node of the "other" part of the merge (hexified version)
     F: a file to be merged entry
     C: a change/delete or delete/change conflict
     D: a file that the external merge driver will merge internally
        (experimental)
     P: a path conflict (file vs directory)
     m: the external merge driver defined for this merge plus its run state
        (experimental)
     f: a (filename, dictionary) tuple of optional values for a given file
     X: unsupported mandatory record type (used in tests)
     x: unsupported advisory record type (used in tests)
     l: the labels for the parts of the merge.
 
     Merge driver run states (experimental):
     u: driver-resolved files unmarked -- needs to be run next time we're about
        to resolve or commit
     m: driver-resolved files marked -- only needs to be run before commit
     s: success/skipped -- does not need to be run any more
 
     Merge record states (stored in self._state, indexed by filename):
     u: unresolved conflict
     r: resolved conflict
     pu: unresolved path conflict (file conflicts with directory)
     pr: resolved path conflict
     d: driver-resolved conflict
 
     The resolve command transitions between 'u' and 'r' for conflicts and
     'pu' and 'pr' for path conflicts.
     '''
     statepathv1 = 'merge/state'
     statepathv2 = 'merge/state2'
 
     @staticmethod
     def clean(repo, node=None, other=None, labels=None):
         """Initialize a brand new merge state, removing any existing state on
         disk."""
         ms = mergestate(repo)
         ms.reset(node, other, labels)
         return ms
 
     @staticmethod
     def read(repo):
         """Initialize the merge state, reading it from disk."""
         ms = mergestate(repo)
         ms._read()
         return ms
 
     def __init__(self, repo):
         """Initialize the merge state.
 
         Do not use this directly! Instead call read() or clean()."""
         self._repo = repo
         self._dirty = False
         self._labels = None
 
     def reset(self, node=None, other=None, labels=None):
         self._state = {}
         self._stateextras = {}
         self._local = None
         self._other = None
         self._labels = labels
         for var in ('localctx', 'otherctx'):
             if var in vars(self):
                 delattr(self, var)
         if node:
             self._local = node
             self._other = other
         self._readmergedriver = None
         if self.mergedriver:
             self._mdstate = MERGE_DRIVER_STATE_SUCCESS
         else:
             self._mdstate = MERGE_DRIVER_STATE_UNMARKED
         shutil.rmtree(self._repo.vfs.join('merge'), True)
         self._results = {}
         self._dirty = False
 
     def _read(self):
         """Analyse each record content to restore a serialized state from disk
 
         This function process "record" entry produced by the de-serialization
         of on disk file.
         """
         self._state = {}
         self._stateextras = {}
         self._local = None
         self._other = None
         for var in ('localctx', 'otherctx'):
             if var in vars(self):
                 delattr(self, var)
         self._readmergedriver = None
         self._mdstate = MERGE_DRIVER_STATE_SUCCESS
         unsupported = set()
         records = self._readrecords()
         for rtype, record in records:
             if rtype == RECORD_LOCAL:
                 self._local = bin(record)
             elif rtype == RECORD_OTHER:
                 self._other = bin(record)
             elif rtype == RECORD_MERGE_DRIVER_STATE:
                 bits = record.split('\0', 1)
                 mdstate = bits[1]
                 if len(mdstate) != 1 or mdstate not in (
                     MERGE_DRIVER_STATE_UNMARKED, MERGE_DRIVER_STATE_MARKED,
                     MERGE_DRIVER_STATE_SUCCESS):
                     # the merge driver should be idempotent, so just rerun it
                     mdstate = MERGE_DRIVER_STATE_UNMARKED
 
                 self._readmergedriver = bits[0]
                 self._mdstate = mdstate
             elif rtype in (RECORD_MERGED, RECORD_CHANGEDELETE_CONFLICT,
                            RECORD_PATH_CONFLICT, RECORD_MERGE_DRIVER_MERGE):
                 bits = record.split('\0')
                 self._state[bits[0]] = bits[1:]
             elif rtype == RECORD_FILE_VALUES:
                 filename, rawextras = record.split('\0', 1)
                 extraparts = rawextras.split('\0')
                 extras = {}
                 i = 0
                 while i < len(extraparts):
                     extras[extraparts[i]] = extraparts[i + 1]
                     i += 2
 
                 self._stateextras[filename] = extras
             elif rtype == RECORD_LABELS:
                 labels = record.split('\0', 2)
                 self._labels = [l for l in labels if len(l) > 0]
             elif not rtype.islower():
                 unsupported.add(rtype)
         self._results = {}
         self._dirty = False
 
         if unsupported:
             raise error.UnsupportedMergeRecords(unsupported)
 
     def _readrecords(self):
         """Read merge state from disk and return a list of record (TYPE, data)
 
         We read data from both v1 and v2 files and decide which one to use.
 
         V1 has been used by version prior to 2.9.1 and contains less data than
         v2. We read both versions and check if no data in v2 contradicts
         v1. If there is not contradiction we can safely assume that both v1
         and v2 were written at the same time and use the extract data in v2. If
         there is contradiction we ignore v2 content as we assume an old version
         of Mercurial has overwritten the mergestate file and left an old v2
         file around.
 
         returns list of record [(TYPE, data), ...]"""
         v1records = self._readrecordsv1()
         v2records = self._readrecordsv2()
         if self._v1v2match(v1records, v2records):
             return v2records
         else:
             # v1 file is newer than v2 file, use it
             # we have to infer the "other" changeset of the merge
             # we cannot do better than that with v1 of the format
             mctx = self._repo[None].parents()[-1]
             v1records.append((RECORD_OTHER, mctx.hex()))
             # add place holder "other" file node information
             # nobody is using it yet so we do no need to fetch the data
             # if mctx was wrong `mctx[bits[-2]]` may fails.
             for idx, r in enumerate(v1records):
                 if r[0] == RECORD_MERGED:
                     bits = r[1].split('\0')
                     bits.insert(-2, '')
                     v1records[idx] = (r[0], '\0'.join(bits))
             return v1records
 
     def _v1v2match(self, v1records, v2records):
         oldv2 = set() # old format version of v2 record
         for rec in v2records:
             if rec[0] == RECORD_LOCAL:
                 oldv2.add(rec)
             elif rec[0] == RECORD_MERGED:
                 # drop the onode data (not contained in v1)
                 oldv2.add((RECORD_MERGED, _droponode(rec[1])))
         for rec in v1records:
             if rec not in oldv2:
                 return False
         else:
             return True
 
     def _readrecordsv1(self):
         """read on disk merge state for version 1 file
 
         returns list of record [(TYPE, data), ...]
 
         Note: the "F" data from this file are one entry short
               (no "other file node" entry)
         """
         records = []
         try:
             f = self._repo.vfs(self.statepathv1)
             for i, l in enumerate(f):
                 if i == 0:
                     records.append((RECORD_LOCAL, l[:-1]))
                 else:
                     records.append((RECORD_MERGED, l[:-1]))
             f.close()
         except IOError as err:
             if err.errno != errno.ENOENT:
                 raise
         return records
 
     def _readrecordsv2(self):
         """read on disk merge state for version 2 file
 
         This format is a list of arbitrary records of the form:
 
           [type][length][content]
 
         `type` is a single character, `length` is a 4 byte integer, and
         `content` is an arbitrary byte sequence of length `length`.
 
         Mercurial versions prior to 3.7 have a bug where if there are
         unsupported mandatory merge records, attempting to clear out the merge
         state with hg update --clean or similar aborts. The 't' record type
         works around that by writing out what those versions treat as an
         advisory record, but later versions interpret as special: the first
         character is the 'real' record type and everything onwards is the data.
 
         Returns list of records [(TYPE, data), ...]."""
         records = []
         try:
             f = self._repo.vfs(self.statepathv2)
             data = f.read()
             off = 0
             end = len(data)
             while off < end:
                 rtype = data[off:off + 1]
                 off += 1
                 length = _unpack('>I', data[off:(off + 4)])[0]
                 off += 4
                 record = data[off:(off + length)]
                 off += length
                 if rtype == RECORD_OVERRIDE:
                     rtype, record = record[0:1], record[1:]
                 records.append((rtype, record))
             f.close()
         except IOError as err:
             if err.errno != errno.ENOENT:
                 raise
         return records
 
     @util.propertycache
     def mergedriver(self):
         # protect against the following:
         # - A configures a malicious merge driver in their hgrc, then
         #   pauses the merge
         # - A edits their hgrc to remove references to the merge driver
         # - A gives a copy of their entire repo, including .hg, to B
         # - B inspects .hgrc and finds it to be clean
         # - B then continues the merge and the malicious merge driver
         #  gets invoked
         configmergedriver = self._repo.ui.config('experimental', 'mergedriver')
         if (self._readmergedriver is not None
             and self._readmergedriver != configmergedriver):
             raise error.ConfigError(
                 _("merge driver changed since merge started"),
                 hint=_("revert merge driver change or abort merge"))
 
         return configmergedriver
 
     @util.propertycache
     def localctx(self):
         if self._local is None:
             msg = "localctx accessed but self._local isn't set"
             raise error.ProgrammingError(msg)
         return self._repo[self._local]
 
     @util.propertycache
     def otherctx(self):
         if self._other is None:
             msg = "otherctx accessed but self._other isn't set"
             raise error.ProgrammingError(msg)
         return self._repo[self._other]
 
     def active(self):
         """Whether mergestate is active.
 
         Returns True if there appears to be mergestate. This is a rough proxy
         for "is a merge in progress."
         """
         # Check local variables before looking at filesystem for performance
         # reasons.
         return bool(self._local) or bool(self._state) or \
                self._repo.vfs.exists(self.statepathv1) or \
                self._repo.vfs.exists(self.statepathv2)
 
     def commit(self):
         """Write current state on disk (if necessary)"""
         if self._dirty:
             records = self._makerecords()
             self._writerecords(records)
             self._dirty = False
 
     def _makerecords(self):
         records = []
         records.append((RECORD_LOCAL, hex(self._local)))
         records.append((RECORD_OTHER, hex(self._other)))
         if self.mergedriver:
             records.append((RECORD_MERGE_DRIVER_STATE, '\0'.join([
                 self.mergedriver, self._mdstate])))
         # Write out state items. In all cases, the value of the state map entry
         # is written as the contents of the record. The record type depends on
         # the type of state that is stored, and capital-letter records are used
         # to prevent older versions of Mercurial that do not support the feature
         # from loading them.
         for filename, v in self._state.iteritems():
             if v[0] == MERGE_RECORD_DRIVER_RESOLVED:
                 # Driver-resolved merge. These are stored in 'D' records.
                 records.append((RECORD_MERGE_DRIVER_MERGE,
                                 '\0'.join([filename] + v)))
             elif v[0] in (MERGE_RECORD_UNRESOLVED_PATH,
                           MERGE_RECORD_RESOLVED_PATH):
                 # Path conflicts. These are stored in 'P' records.  The current
                 # resolution state ('pu' or 'pr') is stored within the record.
                 records.append((RECORD_PATH_CONFLICT,
                                 '\0'.join([filename] + v)))
             elif v[1] == nullhex or v[6] == nullhex:
                 # Change/Delete or Delete/Change conflicts. These are stored in
                 # 'C' records. v[1] is the local file, and is nullhex when the
                 # file is deleted locally ('dc'). v[6] is the remote file, and
                 # is nullhex when the file is deleted remotely ('cd').
                 records.append((RECORD_CHANGEDELETE_CONFLICT,
                                 '\0'.join([filename] + v)))
             else:
                 # Normal files.  These are stored in 'F' records.
                 records.append((RECORD_MERGED,
                                 '\0'.join([filename] + v)))
         for filename, extras in sorted(self._stateextras.iteritems()):
             rawextras = '\0'.join('%s\0%s' % (k, v) for k, v in
                                   extras.iteritems())
             records.append((RECORD_FILE_VALUES,
                             '%s\0%s' % (filename, rawextras)))
         if self._labels is not None:
             labels = '\0'.join(self._labels)
             records.append((RECORD_LABELS, labels))
         return records
 
     def _writerecords(self, records):
         """Write current state on disk (both v1 and v2)"""
         self._writerecordsv1(records)
         self._writerecordsv2(records)
 
     def _writerecordsv1(self, records):
         """Write current state on disk in a version 1 file"""
         f = self._repo.vfs(self.statepathv1, 'wb')
         irecords = iter(records)
         lrecords = next(irecords)
         assert lrecords[0] == RECORD_LOCAL
         f.write(hex(self._local) + '\n')
         for rtype, data in irecords:
             if rtype == RECORD_MERGED:
                 f.write('%s\n' % _droponode(data))
         f.close()
 
     def _writerecordsv2(self, records):
         """Write current state on disk in a version 2 file
 
         See the docstring for _readrecordsv2 for why we use 't'."""
         # these are the records that all version 2 clients can read
         allowlist = (RECORD_LOCAL, RECORD_OTHER, RECORD_MERGED)
         f = self._repo.vfs(self.statepathv2, 'wb')
         for key, data in records:
             assert len(key) == 1
             if key not in allowlist:
                 key, data = RECORD_OVERRIDE, '%s%s' % (key, data)
             format = '>sI%is' % len(data)
             f.write(_pack(format, key, len(data), data))
         f.close()
 
     def add(self, fcl, fco, fca, fd):
         """add a new (potentially?) conflicting file the merge state
         fcl: file context for local,
         fco: file context for remote,
         fca: file context for ancestors,
         fd:  file path of the resulting merge.
 
         note: also write the local version to the `.hg/merge` directory.
         """
         if fcl.isabsent():
             hash = nullhex
         else:
             hash = hex(hashlib.sha1(fcl.path()).digest())
             self._repo.vfs.write('merge/' + hash, fcl.data())
         self._state[fd] = [MERGE_RECORD_UNRESOLVED, hash, fcl.path(),
                            fca.path(), hex(fca.filenode()),
                            fco.path(), hex(fco.filenode()),
                            fcl.flags()]
         self._stateextras[fd] = {'ancestorlinknode': hex(fca.node())}
         self._dirty = True
 
     def addpath(self, path, frename, forigin):
         """add a new conflicting path to the merge state
         path:    the path that conflicts
         frename: the filename the conflicting file was renamed to
         forigin: origin of the file ('l' or 'r' for local/remote)
         """
         self._state[path] = [MERGE_RECORD_UNRESOLVED_PATH, frename, forigin]
         self._dirty = True
 
     def __contains__(self, dfile):
         return dfile in self._state
 
     def __getitem__(self, dfile):
         return self._state[dfile][0]
 
     def __iter__(self):
         return iter(sorted(self._state))
 
     def files(self):
         return self._state.keys()
 
     def mark(self, dfile, state):
         self._state[dfile][0] = state
         self._dirty = True
 
     def mdstate(self):
         return self._mdstate
 
     def unresolved(self):
         """Obtain the paths of unresolved files."""
 
         for f, entry in self._state.iteritems():
             if entry[0] in (MERGE_RECORD_UNRESOLVED,
                             MERGE_RECORD_UNRESOLVED_PATH):
                 yield f
 
     def driverresolved(self):
         """Obtain the paths of driver-resolved files."""
 
         for f, entry in self._state.items():
             if entry[0] == MERGE_RECORD_DRIVER_RESOLVED:
                 yield f
 
     def extras(self, filename):
         return self._stateextras.setdefault(filename, {})
 
     def _resolve(self, preresolve, dfile, wctx):
         """rerun merge process for file path `dfile`"""
         if self[dfile] in (MERGE_RECORD_RESOLVED,
                            MERGE_RECORD_DRIVER_RESOLVED):
             return True, 0
         stateentry = self._state[dfile]
         state, hash, lfile, afile, anode, ofile, onode, flags = stateentry
         octx = self._repo[self._other]
         extras = self.extras(dfile)
         anccommitnode = extras.get('ancestorlinknode')
         if anccommitnode:
             actx = self._repo[anccommitnode]
         else:
             actx = None
         fcd = self._filectxorabsent(hash, wctx, dfile)
         fco = self._filectxorabsent(onode, octx, ofile)
         # TODO: move this to filectxorabsent
         fca = self._repo.filectx(afile, fileid=anode, changectx=actx)
         # "premerge" x flags
         flo = fco.flags()
         fla = fca.flags()
         if 'x' in flags + flo + fla and 'l' not in flags + flo + fla:
             if fca.node() == nullid and flags != flo:
                 if preresolve:
                     self._repo.ui.warn(
                         _('warning: cannot merge flags for %s '
                           'without common ancestor - keeping local flags\n')
                         % afile)
             elif flags == fla:
                 flags = flo
         if preresolve:
             # restore local
             if hash != nullhex:
                 f = self._repo.vfs('merge/' + hash)
                 wctx[dfile].write(f.read(), flags)
                 f.close()
             else:
                 wctx[dfile].remove(ignoremissing=True)
             complete, r, deleted = filemerge.premerge(self._repo, wctx,
                                                       self._local, lfile, fcd,
                                                       fco, fca,
                                                       labels=self._labels)
         else:
             complete, r, deleted = filemerge.filemerge(self._repo, wctx,
                                                        self._local, lfile, fcd,
                                                        fco, fca,
                                                        labels=self._labels)
         if r is None:
             # no real conflict
             del self._state[dfile]
             self._stateextras.pop(dfile, None)
             self._dirty = True
         elif not r:
             self.mark(dfile, MERGE_RECORD_RESOLVED)
 
         if complete:
             action = None
             if deleted:
                 if fcd.isabsent():
                     # dc: local picked. Need to drop if present, which may
                     # happen on re-resolves.
                     action = ACTION_FORGET
                 else:
                     # cd: remote picked (or otherwise deleted)
                     action = ACTION_REMOVE
             else:
                 if fcd.isabsent(): # dc: remote picked
                     action = ACTION_GET
                 elif fco.isabsent(): # cd: local picked
                     if dfile in self.localctx:
                         action = ACTION_ADD_MODIFIED
                     else:
                         action = ACTION_ADD
                 # else: regular merges (no action necessary)
             self._results[dfile] = r, action
 
         return complete, r
 
     def _filectxorabsent(self, hexnode, ctx, f):
         if hexnode == nullhex:
             return filemerge.absentfilectx(ctx, f)
         else:
             return ctx[f]
 
     def preresolve(self, dfile, wctx):
         """run premerge process for dfile
 
         Returns whether the merge is complete, and the exit code."""
         return self._resolve(True, dfile, wctx)
 
     def resolve(self, dfile, wctx):
         """run merge process (assuming premerge was run) for dfile
 
         Returns the exit code of the merge."""
         return self._resolve(False, dfile, wctx)[1]
 
     def counts(self):
         """return counts for updated, merged and removed files in this
         session"""
         updated, merged, removed = 0, 0, 0
         for r, action in self._results.itervalues():
             if r is None:
                 updated += 1
             elif r == 0:
                 if action == ACTION_REMOVE:
                     removed += 1
                 else:
                     merged += 1
         return updated, merged, removed
 
     def unresolvedcount(self):
         """get unresolved count for this merge (persistent)"""
         return len(list(self.unresolved()))
 
     def actions(self):
         """return lists of actions to perform on the dirstate"""
         actions = {
             ACTION_REMOVE: [],
             ACTION_FORGET: [],
             ACTION_ADD: [],
             ACTION_ADD_MODIFIED: [],
             ACTION_GET: [],
         }
         for f, (r, action) in self._results.iteritems():
             if action is not None:
                 actions[action].append((f, None, "merge result"))
         return actions
 
     def recordactions(self):
         """record remove/add/get actions in the dirstate"""
         branchmerge = self._repo.dirstate.p2() != nullid
         recordupdates(self._repo, self.actions(), branchmerge)
 
     def queueremove(self, f):
         """queues a file to be removed from the dirstate
 
         Meant for use by custom merge drivers."""
         self._results[f] = 0, ACTION_REMOVE
 
     def queueadd(self, f):
         """queues a file to be added to the dirstate
 
         Meant for use by custom merge drivers."""
         self._results[f] = 0, ACTION_ADD
 
     def queueget(self, f):
         """queues a file to be marked modified in the dirstate
 
         Meant for use by custom merge drivers."""
         self._results[f] = 0, ACTION_GET
 
 def _getcheckunknownconfig(repo, section, name):
     config = repo.ui.config(section, name)
     valid = ['abort', 'ignore', 'warn']
     if config not in valid:
         validstr = ', '.join(["'" + v + "'" for v in valid])
         raise error.ConfigError(_("%s.%s not valid "
                                   "('%s' is none of %s)")
                                 % (section, name, config, validstr))
     return config
 
 def _checkunknownfile(repo, wctx, mctx, f, f2=None):
     if wctx.isinmemory():
         # Nothing to do in IMM because nothing in the "working copy" can be an
         # unknown file.
         #
         # Note that we should bail out here, not in ``_checkunknownfiles()``,
         # because that function does other useful work.
         return False
 
     if f2 is None:
         f2 = f
     return (repo.wvfs.audit.check(f)
         and repo.wvfs.isfileorlink(f)
         and repo.dirstate.normalize(f) not in repo.dirstate
         and mctx[f2].cmp(wctx[f]))
 
 class _unknowndirschecker(object):
     """
     Look for any unknown files or directories that may have a path conflict
     with a file.  If any path prefix of the file exists as a file or link,
     then it conflicts.  If the file itself is a directory that contains any
     file that is not tracked, then it conflicts.
 
     Returns the shortest path at which a conflict occurs, or None if there is
     no conflict.
     """
     def __init__(self):
         # A set of paths known to be good.  This prevents repeated checking of
         # dirs.  It will be updated with any new dirs that are checked and found
         # to be safe.
         self._unknowndircache = set()
 
         # A set of paths that are known to be absent.  This prevents repeated
         # checking of subdirectories that are known not to exist. It will be
         # updated with any new dirs that are checked and found to be absent.
         self._missingdircache = set()
 
     def __call__(self, repo, wctx, f):
         if wctx.isinmemory():
             # Nothing to do in IMM for the same reason as ``_checkunknownfile``.
             return False
 
         # Check for path prefixes that exist as unknown files.
         for p in reversed(list(util.finddirs(f))):
             if p in self._missingdircache:
                 return
             if p in self._unknowndircache:
                 continue
             if repo.wvfs.audit.check(p):
                 if (repo.wvfs.isfileorlink(p)
                         and repo.dirstate.normalize(p) not in repo.dirstate):
                     return p
                 if not repo.wvfs.lexists(p):
                     self._missingdircache.add(p)
                     return
                 self._unknowndircache.add(p)
 
         # Check if the file conflicts with a directory containing unknown files.
         if repo.wvfs.audit.check(f) and repo.wvfs.isdir(f):
             # Does the directory contain any files that are not in the dirstate?
             for p, dirs, files in repo.wvfs.walk(f):
                 for fn in files:
                     relf = util.pconvert(repo.wvfs.reljoin(p, fn))
                     relf = repo.dirstate.normalize(relf, isknown=True)
                     if relf not in repo.dirstate:
                         return f
         return None
 
 def _checkunknownfiles(repo, wctx, mctx, force, actions, mergeforce):
     """
     Considers any actions that care about the presence of conflicting unknown
     files. For some actions, the result is to abort; for others, it is to
     choose a different action.
     """
     fileconflicts = set()
     pathconflicts = set()
     warnconflicts = set()
     abortconflicts = set()
     unknownconfig = _getcheckunknownconfig(repo, 'merge', 'checkunknown')
     ignoredconfig = _getcheckunknownconfig(repo, 'merge', 'checkignored')
     pathconfig = repo.ui.configbool('experimental', 'merge.checkpathconflicts')
     if not force:
         def collectconflicts(conflicts, config):
             if config == 'abort':
                 abortconflicts.update(conflicts)
             elif config == 'warn':
                 warnconflicts.update(conflicts)
 
         checkunknowndirs = _unknowndirschecker()
         for f, (m, args, msg) in actions.iteritems():
             if m in (ACTION_CREATED, ACTION_DELETED_CHANGED):
                 if _checkunknownfile(repo, wctx, mctx, f):
                     fileconflicts.add(f)
                 elif pathconfig and f not in wctx:
                     path = checkunknowndirs(repo, wctx, f)
                     if path is not None:
                         pathconflicts.add(path)
             elif m == ACTION_LOCAL_DIR_RENAME_GET:
                 if _checkunknownfile(repo, wctx, mctx, f, args[0]):
                     fileconflicts.add(f)
 
         allconflicts = fileconflicts | pathconflicts
         ignoredconflicts = set([c for c in allconflicts
                                 if repo.dirstate._ignore(c)])
         unknownconflicts = allconflicts - ignoredconflicts
         collectconflicts(ignoredconflicts, ignoredconfig)
         collectconflicts(unknownconflicts, unknownconfig)
     else:
         for f, (m, args, msg) in actions.iteritems():
             if m == ACTION_CREATED_MERGE:
                 fl2, anc = args
                 different = _checkunknownfile(repo, wctx, mctx, f)
                 if repo.dirstate._ignore(f):
                     config = ignoredconfig
                 else:
                     config = unknownconfig
 
                 # The behavior when force is True is described by this table:
                 #  config  different  mergeforce  |    action    backup
                 #    *         n          *       |      get        n
                 #    *         y          y       |     merge       -
                 #   abort      y          n       |     merge       -   (1)
                 #   warn       y          n       |  warn + get     y
                 #  ignore      y          n       |      get        y
                 #
                 # (1) this is probably the wrong behavior here -- we should
                 #     probably abort, but some actions like rebases currently
                 #     don't like an abort happening in the middle of
                 #     merge.update.
                 if not different:
                     actions[f] = (ACTION_GET, (fl2, False), 'remote created')
                 elif mergeforce or config == 'abort':
                     actions[f] = (ACTION_MERGE, (f, f, None, False, anc),
                                   'remote differs from untracked local')
                 elif config == 'abort':
                     abortconflicts.add(f)
                 else:
                     if config == 'warn':
                         warnconflicts.add(f)
                     actions[f] = (ACTION_GET, (fl2, True), 'remote created')
 
     for f in sorted(abortconflicts):
         warn = repo.ui.warn
         if f in pathconflicts:
             if repo.wvfs.isfileorlink(f):
                 warn(_("%s: untracked file conflicts with directory\n") % f)
             else:
                 warn(_("%s: untracked directory conflicts with file\n") % f)
         else:
             warn(_("%s: untracked file differs\n") % f)
     if abortconflicts:
         raise error.Abort(_("untracked files in working directory "
                             "differ from files in requested revision"))
 
     for f in sorted(warnconflicts):
         if repo.wvfs.isfileorlink(f):
             repo.ui.warn(_("%s: replacing untracked file\n") % f)
         else:
             repo.ui.warn(_("%s: replacing untracked files in directory\n") % f)
 
     for f, (m, args, msg) in actions.iteritems():
         if m == ACTION_CREATED:
             backup = (f in fileconflicts or f in pathconflicts or
                       any(p in pathconflicts for p in util.finddirs(f)))
             flags, = args
             actions[f] = (ACTION_GET, (flags, backup), msg)
 
 def _forgetremoved(wctx, mctx, branchmerge):
     """
     Forget removed files
 
     If we're jumping between revisions (as opposed to merging), and if
     neither the working directory nor the target rev has the file,
     then we need to remove it from the dirstate, to prevent the
     dirstate from listing the file when it is no longer in the
     manifest.
 
     If we're merging, and the other revision has removed a file
     that is not present in the working directory, we need to mark it
     as removed.
     """
 
     actions = {}
     m = ACTION_FORGET
     if branchmerge:
         m = ACTION_REMOVE
     for f in wctx.deleted():
         if f not in mctx:
             actions[f] = m, None, "forget deleted"
 
     if not branchmerge:
         for f in wctx.removed():
             if f not in mctx:
                 actions[f] = ACTION_FORGET, None, "forget removed"
 
     return actions
 
 def _checkcollision(repo, wmf, actions):
     """
     Check for case-folding collisions.
     """
 
     # If the repo is narrowed, filter out files outside the narrowspec.
     narrowmatch = repo.narrowmatch()
     if not narrowmatch.always():
         wmf = wmf.matches(narrowmatch)
         if actions:
             narrowactions = {}
             for m, actionsfortype in actions.iteritems():
                 narrowactions[m] = []
                 for (f, args, msg) in actionsfortype:
                     if narrowmatch(f):
                         narrowactions[m].append((f, args, msg))
             actions = narrowactions
 
     # build provisional merged manifest up
     pmmf = set(wmf)
 
     if actions:
         # KEEP and EXEC are no-op
         for m in (ACTION_ADD, ACTION_ADD_MODIFIED, ACTION_FORGET, ACTION_GET,
                   ACTION_CHANGED_DELETED, ACTION_DELETED_CHANGED):
             for f, args, msg in actions[m]:
                 pmmf.add(f)
         for f, args, msg in actions[ACTION_REMOVE]:
             pmmf.discard(f)
         for f, args, msg in actions[ACTION_DIR_RENAME_MOVE_LOCAL]:
             f2, flags = args
             pmmf.discard(f2)
             pmmf.add(f)
         for f, args, msg in actions[ACTION_LOCAL_DIR_RENAME_GET]:
             pmmf.add(f)
         for f, args, msg in actions[ACTION_MERGE]:
             f1, f2, fa, move, anc = args
             if move:
                 pmmf.discard(f1)
             pmmf.add(f)
 
     # check case-folding collision in provisional merged manifest
     foldmap = {}
     for f in pmmf:
         fold = util.normcase(f)
         if fold in foldmap:
             raise error.Abort(_("case-folding collision between %s and %s")
                              % (f, foldmap[fold]))
         foldmap[fold] = f
 
     # check case-folding of directories
     foldprefix = unfoldprefix = lastfull = ''
     for fold, f in sorted(foldmap.items()):
         if fold.startswith(foldprefix) and not f.startswith(unfoldprefix):
             # the folded prefix matches but actual casing is different
             raise error.Abort(_("case-folding collision between "
                                 "%s and directory of %s") % (lastfull, f))
         foldprefix = fold + '/'
         unfoldprefix = f + '/'
         lastfull = f
 
 def driverpreprocess(repo, ms, wctx, labels=None):
     """run the preprocess step of the merge driver, if any
 
     This is currently not implemented -- it's an extension point."""
     return True
 
 def driverconclude(repo, ms, wctx, labels=None):
     """run the conclude step of the merge driver, if any
 
     This is currently not implemented -- it's an extension point."""
     return True
 
 def _filesindirs(repo, manifest, dirs):
     """
     Generator that yields pairs of all the files in the manifest that are found
     inside the directories listed in dirs, and which directory they are found
     in.
     """
     for f in manifest:
         for p in util.finddirs(f):
             if p in dirs:
                 yield f, p
                 break
 
 def checkpathconflicts(repo, wctx, mctx, actions):
     """
     Check if any actions introduce path conflicts in the repository, updating
     actions to record or handle the path conflict accordingly.
     """
     mf = wctx.manifest()
 
     # The set of local files that conflict with a remote directory.
     localconflicts = set()
 
     # The set of directories that conflict with a remote file, and so may cause
     # conflicts if they still contain any files after the merge.
     remoteconflicts = set()
 
     # The set of directories that appear as both a file and a directory in the
     # remote manifest.  These indicate an invalid remote manifest, which
     # can't be updated to cleanly.
     invalidconflicts = set()
 
     # The set of directories that contain files that are being created.
     createdfiledirs = set()
 
     # The set of files deleted by all the actions.
     deletedfiles = set()
 
     for f, (m, args, msg) in actions.items():
         if m in (ACTION_CREATED, ACTION_DELETED_CHANGED, ACTION_MERGE,
                  ACTION_CREATED_MERGE):
             # This action may create a new local file.
             createdfiledirs.update(util.finddirs(f))
             if mf.hasdir(f):
                 # The file aliases a local directory.  This might be ok if all
                 # the files in the local directory are being deleted.  This
                 # will be checked once we know what all the deleted files are.
                 remoteconflicts.add(f)
         # Track the names of all deleted files.
         if m == ACTION_REMOVE:
             deletedfiles.add(f)
         if m == ACTION_MERGE:
             f1, f2, fa, move, anc = args
             if move:
                 deletedfiles.add(f1)
         if m == ACTION_DIR_RENAME_MOVE_LOCAL:
             f2, flags = args
             deletedfiles.add(f2)
 
     # Check all directories that contain created files for path conflicts.
     for p in createdfiledirs:
         if p in mf:
             if p in mctx:
                 # A file is in a directory which aliases both a local
                 # and a remote file.  This is an internal inconsistency
                 # within the remote manifest.
                 invalidconflicts.add(p)
             else:
                 # A file is in a directory which aliases a local file.
                 # We will need to rename the local file.
                 localconflicts.add(p)
         if p in actions and actions[p][0] in (ACTION_CREATED,
                                               ACTION_DELETED_CHANGED,
                                               ACTION_MERGE,
                                               ACTION_CREATED_MERGE):
             # The file is in a directory which aliases a remote file.
             # This is an internal inconsistency within the remote
             # manifest.
             invalidconflicts.add(p)
 
     # Rename all local conflicting files that have not been deleted.
     for p in localconflicts:
         if p not in deletedfiles:
             ctxname = bytes(wctx).rstrip('+')
             pnew = util.safename(p, ctxname, wctx, set(actions.keys()))
             actions[pnew] = (ACTION_PATH_CONFLICT_RESOLVE, (p,),
                              'local path conflict')
             actions[p] = (ACTION_PATH_CONFLICT, (pnew, 'l'),
                           'path conflict')
 
     if remoteconflicts:
         # Check if all files in the conflicting directories have been removed.
         ctxname = bytes(mctx).rstrip('+')
         for f, p in _filesindirs(repo, mf, remoteconflicts):
             if f not in deletedfiles:
                 m, args, msg = actions[p]
                 pnew = util.safename(p, ctxname, wctx, set(actions.keys()))
                 if m in (ACTION_DELETED_CHANGED, ACTION_MERGE):
                     # Action was merge, just update target.
                     actions[pnew] = (m, args, msg)
                 else:
                     # Action was create, change to renamed get action.
                     fl = args[0]
                     actions[pnew] = (ACTION_LOCAL_DIR_RENAME_GET, (p, fl),
                                      'remote path conflict')
                 actions[p] = (ACTION_PATH_CONFLICT, (pnew, ACTION_REMOVE),
                               'path conflict')
                 remoteconflicts.remove(p)
                 break
 
     if invalidconflicts:
         for p in invalidconflicts:
             repo.ui.warn(_("%s: is both a file and a directory\n") % p)
         raise error.Abort(_("destination manifest contains path conflicts"))
 
 def _filternarrowactions(narrowmatch, branchmerge, actions):
     """
     Filters out actions that can ignored because the repo is narrowed.
 
     Raise an exception if the merge cannot be completed because the repo is
     narrowed.
     """
     nooptypes = set(['k']) # TODO: handle with nonconflicttypes
     nonconflicttypes = set('a am c cm f g r e'.split())
     # We mutate the items in the dict during iteration, so iterate
     # over a copy.
     for f, action in list(actions.items()):
         if narrowmatch(f):
             pass
         elif not branchmerge:
             del actions[f] # just updating, ignore changes outside clone
         elif action[0] in nooptypes:
             del actions[f] # merge does not affect file
         elif action[0] in nonconflicttypes:
             raise error.Abort(_('merge affects file \'%s\' outside narrow, '
                                 'which is not yet supported') % f,
                               hint=_('merging in the other direction '
                                      'may work'))
         else:
             raise error.Abort(_('conflict in file \'%s\' is outside '
                                 'narrow clone') % f)
 
 def manifestmerge(repo, wctx, p2, pa, branchmerge, force, matcher,
                   acceptremote, followcopies, forcefulldiff=False):
     """
     Merge wctx and p2 with ancestor pa and generate merge action list
 
     branchmerge and force are as passed in to update
     matcher = matcher to filter file lists
     acceptremote = accept the incoming changes without prompting
     """
     if matcher is not None and matcher.always():
         matcher = None
 
     copy, movewithdir, diverge, renamedelete, dirmove = {}, {}, {}, {}, {}
 
     # manifests fetched in order are going to be faster, so prime the caches
     [x.manifest() for x in
      sorted(wctx.parents() + [p2, pa], key=scmutil.intrev)]
 
     if followcopies:
         ret = copies.mergecopies(repo, wctx, p2, pa)
         copy, movewithdir, diverge, renamedelete, dirmove = ret
 
     boolbm = pycompat.bytestr(bool(branchmerge))
     boolf = pycompat.bytestr(bool(force))
     boolm = pycompat.bytestr(bool(matcher))
     repo.ui.note(_("resolving manifests\n"))
     repo.ui.debug(" branchmerge: %s, force: %s, partial: %s\n"
                   % (boolbm, boolf, boolm))
     repo.ui.debug(" ancestor: %s, local: %s, remote: %s\n" % (pa, wctx, p2))
 
     m1, m2, ma = wctx.manifest(), p2.manifest(), pa.manifest()
     copied = set(copy.values())
     copied.update(movewithdir.values())
 
     if '.hgsubstate' in m1:
         # check whether sub state is modified
         if any(wctx.sub(s).dirty() for s in wctx.substate):
             m1['.hgsubstate'] = modifiednodeid
 
     # Don't use m2-vs-ma optimization if:
     # - ma is the same as m1 or m2, which we're just going to diff again later
     # - The caller specifically asks for a full diff, which is useful during bid
     #   merge.
     if (pa not in ([wctx, p2] + wctx.parents()) and not forcefulldiff):
         # Identify which files are relevant to the merge, so we can limit the
         # total m1-vs-m2 diff to just those files. This has significant
         # performance benefits in large repositories.
         relevantfiles = set(ma.diff(m2).keys())
 
         # For copied and moved files, we need to add the source file too.
         for copykey, copyvalue in copy.iteritems():
             if copyvalue in relevantfiles:
                 relevantfiles.add(copykey)
         for movedirkey in movewithdir:
             relevantfiles.add(movedirkey)
         filesmatcher = scmutil.matchfiles(repo, relevantfiles)
         matcher = matchmod.intersectmatchers(matcher, filesmatcher)
 
     diff = m1.diff(m2, match=matcher)
 
     if matcher is None:
         matcher = matchmod.always('', '')
 
     actions = {}
     for f, ((n1, fl1), (n2, fl2)) in diff.iteritems():
         if n1 and n2: # file exists on both local and remote side
             if f not in ma:
                 fa = copy.get(f, None)
                 if fa is not None:
                     actions[f] = (ACTION_MERGE, (f, f, fa, False, pa.node()),
                                   'both renamed from %s' % fa)
                 else:
                     actions[f] = (ACTION_MERGE, (f, f, None, False, pa.node()),
                                   'both created')
             else:
                 a = ma[f]
                 fla = ma.flags(f)
                 nol = 'l' not in fl1 + fl2 + fla
                 if n2 == a and fl2 == fla:
                     actions[f] = (ACTION_KEEP, (), 'remote unchanged')
                 elif n1 == a and fl1 == fla: # local unchanged - use remote
                     if n1 == n2: # optimization: keep local content
                         actions[f] = (ACTION_EXEC, (fl2,), 'update permissions')
                     else:
                         actions[f] = (ACTION_GET, (fl2, False),
                                       'remote is newer')
                 elif nol and n2 == a: # remote only changed 'x'
                     actions[f] = (ACTION_EXEC, (fl2,), 'update permissions')
                 elif nol and n1 == a: # local only changed 'x'
                     actions[f] = (ACTION_GET, (fl1, False), 'remote is newer')
                 else: # both changed something
                     actions[f] = (ACTION_MERGE, (f, f, f, False, pa.node()),
                                   'versions differ')
         elif n1: # file exists only on local side
             if f in copied:
                 pass # we'll deal with it on m2 side
             elif f in movewithdir: # directory rename, move local
                 f2 = movewithdir[f]
                 if f2 in m2:
                     actions[f2] = (ACTION_MERGE, (f, f2, None, True, pa.node()),
                                    'remote directory rename, both created')
                 else:
                     actions[f2] = (ACTION_DIR_RENAME_MOVE_LOCAL, (f, fl1),
                                    'remote directory rename - move from %s' % f)
             elif f in copy:
                 f2 = copy[f]
                 actions[f] = (ACTION_MERGE, (f, f2, f2, False, pa.node()),
                               'local copied/moved from %s' % f2)
             elif f in ma: # clean, a different, no remote
                 if n1 != ma[f]:
                     if acceptremote:
                         actions[f] = (ACTION_REMOVE, None, 'remote delete')
                     else:
                         actions[f] = (ACTION_CHANGED_DELETED,
                                       (f, None, f, False, pa.node()),
                                       'prompt changed/deleted')
                 elif n1 == addednodeid:
                     # This extra 'a' is added by working copy manifest to mark
                     # the file as locally added. We should forget it instead of
                     # deleting it.
                     actions[f] = (ACTION_FORGET, None, 'remote deleted')
                 else:
                     actions[f] = (ACTION_REMOVE, None, 'other deleted')
         elif n2: # file exists only on remote side
             if f in copied:
                 pass # we'll deal with it on m1 side
             elif f in movewithdir:
                 f2 = movewithdir[f]
                 if f2 in m1:
                     actions[f2] = (ACTION_MERGE,
                                    (f2, f, None, False, pa.node()),
                                    'local directory rename, both created')
                 else:
                     actions[f2] = (ACTION_LOCAL_DIR_RENAME_GET, (f, fl2),
                                    'local directory rename - get from %s' % f)
             elif f in copy:
                 f2 = copy[f]
                 if f2 in m2:
                     actions[f] = (ACTION_MERGE, (f2, f, f2, False, pa.node()),
                                   'remote copied from %s' % f2)
                 else:
                     actions[f] = (ACTION_MERGE, (f2, f, f2, True, pa.node()),
                                   'remote moved from %s' % f2)
             elif f not in ma:
                 # local unknown, remote created: the logic is described by the
                 # following table:
                 #
                 # force  branchmerge  different  |  action
                 #   n         *           *      |   create
                 #   y         n           *      |   create
                 #   y         y           n      |   create
                 #   y         y           y      |   merge
                 #
                 # Checking whether the files are different is expensive, so we
                 # don't do that when we can avoid it.
                 if not force:
                     actions[f] = (ACTION_CREATED, (fl2,), 'remote created')
                 elif not branchmerge:
                     actions[f] = (ACTION_CREATED, (fl2,), 'remote created')
                 else:
                     actions[f] = (ACTION_CREATED_MERGE, (fl2, pa.node()),
                                   'remote created, get or merge')
             elif n2 != ma[f]:
                 df = None
                 for d in dirmove:
                     if f.startswith(d):
                         # new file added in a directory that was moved
                         df = dirmove[d] + f[len(d):]
                         break
                 if df is not None and df in m1:
                     actions[df] = (ACTION_MERGE, (df, f, f, False, pa.node()),
                                    'local directory rename - respect move '
                                    'from %s' % f)
                 elif acceptremote:
                     actions[f] = (ACTION_CREATED, (fl2,), 'remote recreating')
                 else:
                     actions[f] = (ACTION_DELETED_CHANGED,
                                   (None, f, f, False, pa.node()),
                                   'prompt deleted/changed')
 
     if repo.ui.configbool('experimental', 'merge.checkpathconflicts'):
         # If we are merging, look for path conflicts.
         checkpathconflicts(repo, wctx, p2, actions)
 
     narrowmatch = repo.narrowmatch()
     if not narrowmatch.always():
         # Updates "actions" in place
         _filternarrowactions(narrowmatch, branchmerge, actions)
 
     return actions, diverge, renamedelete
 
 def _resolvetrivial(repo, wctx, mctx, ancestor, actions):
     """Resolves false conflicts where the nodeid changed but the content
        remained the same."""
     # We force a copy of actions.items() because we're going to mutate
     # actions as we resolve trivial conflicts.
     for f, (m, args, msg) in list(actions.items()):
         if (m == ACTION_CHANGED_DELETED and f in ancestor
             and not wctx[f].cmp(ancestor[f])):
             # local did change but ended up with same content
             actions[f] = ACTION_REMOVE, None, 'prompt same'
         elif (m == ACTION_DELETED_CHANGED and f in ancestor
               and not mctx[f].cmp(ancestor[f])):
             # remote did change but ended up with same content
             del actions[f] # don't get = keep local deleted
 
 def calculateupdates(repo, wctx, mctx, ancestors, branchmerge, force,
                      acceptremote, followcopies, matcher=None,
                      mergeforce=False):
     """Calculate the actions needed to merge mctx into wctx using ancestors"""
     # Avoid cycle.
     from . import sparse
 
     if len(ancestors) == 1: # default
         actions, diverge, renamedelete = manifestmerge(
             repo, wctx, mctx, ancestors[0], branchmerge, force, matcher,
             acceptremote, followcopies)
         _checkunknownfiles(repo, wctx, mctx, force, actions, mergeforce)
 
     else: # only when merge.preferancestor=* - the default
         repo.ui.note(
             _("note: merging %s and %s using bids from ancestors %s\n") %
             (wctx, mctx, _(' and ').join(pycompat.bytestr(anc)
                                             for anc in ancestors)))
 
         # Call for bids
         fbids = {} # mapping filename to bids (action method to list af actions)
         diverge, renamedelete = None, None
         for ancestor in ancestors:
             repo.ui.note(_('\ncalculating bids for ancestor %s\n') % ancestor)
             actions, diverge1, renamedelete1 = manifestmerge(
                 repo, wctx, mctx, ancestor, branchmerge, force, matcher,
                 acceptremote, followcopies, forcefulldiff=True)
             _checkunknownfiles(repo, wctx, mctx, force, actions, mergeforce)
 
             # Track the shortest set of warning on the theory that bid
             # merge will correctly incorporate more information
             if diverge is None or len(diverge1) < len(diverge):
                 diverge = diverge1
             if renamedelete is None or len(renamedelete) < len(renamedelete1):
                 renamedelete = renamedelete1
 
             for f, a in sorted(actions.iteritems()):
                 m, args, msg = a
                 repo.ui.debug(' %s: %s -> %s\n' % (f, msg, m))
                 if f in fbids:
                     d = fbids[f]
                     if m in d:
                         d[m].append(a)
                     else:
                         d[m] = [a]
                 else:
                     fbids[f] = {m: [a]}
 
         # Pick the best bid for each file
         repo.ui.note(_('\nauction for merging merge bids\n'))
         actions = {}
         dms = [] # filenames that have dm actions
         for f, bids in sorted(fbids.items()):
             # bids is a mapping from action method to list af actions
             # Consensus?
             if len(bids) == 1: # all bids are the same kind of method
                 m, l = list(bids.items())[0]
                 if all(a == l[0] for a in l[1:]): # len(bids) is > 1
                     repo.ui.note(_(" %s: consensus for %s\n") % (f, m))
                     actions[f] = l[0]
                     if m == ACTION_DIR_RENAME_MOVE_LOCAL:
                         dms.append(f)
                     continue
             # If keep is an option, just do it.
             if ACTION_KEEP in bids:
                 repo.ui.note(_(" %s: picking 'keep' action\n") % f)
                 actions[f] = bids[ACTION_KEEP][0]
                 continue
             # If there are gets and they all agree [how could they not?], do it.
             if ACTION_GET in bids:
                 ga0 = bids[ACTION_GET][0]
                 if all(a == ga0 for a in bids[ACTION_GET][1:]):
                     repo.ui.note(_(" %s: picking 'get' action\n") % f)
                     actions[f] = ga0
                     continue
             # TODO: Consider other simple actions such as mode changes
             # Handle inefficient democrazy.
             repo.ui.note(_(' %s: multiple bids for merge action:\n') % f)
             for m, l in sorted(bids.items()):
                 for _f, args, msg in l:
                     repo.ui.note('  %s -> %s\n' % (msg, m))
             # Pick random action. TODO: Instead, prompt user when resolving
             m, l = list(bids.items())[0]
             repo.ui.warn(_(' %s: ambiguous merge - picked %s action\n') %
                          (f, m))
             actions[f] = l[0]
             if m == ACTION_DIR_RENAME_MOVE_LOCAL:
                 dms.append(f)
             continue
         # Work around 'dm' that can cause multiple actions for the same file
         for f in dms:
             dm, (f0, flags), msg = actions[f]
             assert dm == ACTION_DIR_RENAME_MOVE_LOCAL, dm
             if f0 in actions and actions[f0][0] == ACTION_REMOVE:
                 # We have one bid for removing a file and another for moving it.
                 # These two could be merged as first move and then delete ...
                 # but instead drop moving and just delete.
                 del actions[f]
         repo.ui.note(_('end of auction\n\n'))
 
     _resolvetrivial(repo, wctx, mctx, ancestors[0], actions)
 
     if wctx.rev() is None:
         fractions = _forgetremoved(wctx, mctx, branchmerge)
         actions.update(fractions)
 
     prunedactions = sparse.filterupdatesactions(repo, wctx, mctx, branchmerge,
                                                 actions)
 
     return prunedactions, diverge, renamedelete
 
 def _getcwd():
     try:
         return pycompat.getcwd()
     except OSError as err:
         if err.errno == errno.ENOENT:
             return None
         raise
 
 def batchremove(repo, wctx, actions):
     """apply removes to the working directory
 
     yields tuples for progress updates
     """
     verbose = repo.ui.verbose
     cwd = _getcwd()
     i = 0
     for f, args, msg in actions:
         repo.ui.debug(" %s: %s -> r\n" % (f, msg))
         if verbose:
             repo.ui.note(_("removing %s\n") % f)
         wctx[f].audit()
         try:
             wctx[f].remove(ignoremissing=True)
         except OSError as inst:
             repo.ui.warn(_("update failed to remove %s: %s!\n") %
                          (f, inst.strerror))
         if i == 100:
             yield i, f
             i = 0
         i += 1
     if i > 0:
         yield i, f
 
     if cwd and not _getcwd():
         # cwd was removed in the course of removing files; print a helpful
         # warning.
         repo.ui.warn(_("current directory was removed\n"
                        "(consider changing to repo root: %s)\n") % repo.root)
 
 def batchget(repo, mctx, wctx, actions):
     """apply gets to the working directory
 
     mctx is the context to get from
 
     yields tuples for progress updates
     """
     verbose = repo.ui.verbose
     fctx = mctx.filectx
     ui = repo.ui
     i = 0
     with repo.wvfs.backgroundclosing(ui, expectedcount=len(actions)):
         for f, (flags, backup), msg in actions:
             repo.ui.debug(" %s: %s -> g\n" % (f, msg))
             if verbose:
                 repo.ui.note(_("getting %s\n") % f)
 
             if backup:
                 # If a file or directory exists with the same name, back that
                 # up.  Otherwise, look to see if there is a file that conflicts
                 # with a directory this file is in, and if so, back that up.
                 absf = repo.wjoin(f)
                 if not repo.wvfs.lexists(f):
                     for p in util.finddirs(f):
                         if repo.wvfs.isfileorlink(p):
                             absf = repo.wjoin(p)
                             break
                 orig = scmutil.origpath(ui, repo, absf)
                 if repo.wvfs.lexists(absf):
                     util.rename(absf, orig)
             wctx[f].clearunknown()
             atomictemp = ui.configbool("experimental", "update.atomic-file")
             wctx[f].write(fctx(f).data(), flags, backgroundclose=True,
                           atomictemp=atomictemp)
             if i == 100:
                 yield i, f
                 i = 0
             i += 1
     if i > 0:
         yield i, f
 
 def _prefetchfiles(repo, ctx, actions):
     """Invoke ``scmutil.prefetchfiles()`` for the files relevant to the dict
     of merge actions.  ``ctx`` is the context being merged in."""
 
     # Skipping 'a', 'am', 'f', 'r', 'dm', 'e', 'k', 'p' and 'pr', because they
     # don't touch the context to be merged in.  'cd' is skipped, because
     # changed/deleted never resolves to something from the remote side.
     oplist = [actions[a] for a in (ACTION_GET, ACTION_DELETED_CHANGED,
                                    ACTION_LOCAL_DIR_RENAME_GET, ACTION_MERGE)]
     prefetch = scmutil.prefetchfiles
     matchfiles = scmutil.matchfiles
     prefetch(repo, [ctx.rev()],
              matchfiles(repo,
                         [f for sublist in oplist for f, args, msg in sublist]))
 
 @attr.s(frozen=True)
 class updateresult(object):
     updatedcount = attr.ib()
     mergedcount = attr.ib()
     removedcount = attr.ib()
     unresolvedcount = attr.ib()
 
     def isempty(self):
         return (not self.updatedcount and not self.mergedcount
                 and not self.removedcount and not self.unresolvedcount)
 
 def applyupdates(repo, actions, wctx, mctx, overwrite, labels=None):
     """apply the merge action list to the working directory
 
     wctx is the working copy context
     mctx is the context to be merged into the working copy
 
     Return a tuple of counts (updated, merged, removed, unresolved) that
     describes how many files were affected by the update.
     """
 
     _prefetchfiles(repo, mctx, actions)
 
     updated, merged, removed = 0, 0, 0
     ms = mergestate.clean(repo, wctx.p1().node(), mctx.node(), labels)
     moves = []
     for m, l in actions.items():
         l.sort()
 
     # 'cd' and 'dc' actions are treated like other merge conflicts
     mergeactions = sorted(actions[ACTION_CHANGED_DELETED])
     mergeactions.extend(sorted(actions[ACTION_DELETED_CHANGED]))
     mergeactions.extend(actions[ACTION_MERGE])
     for f, args, msg in mergeactions:
         f1, f2, fa, move, anc = args
         if f == '.hgsubstate': # merged internally
             continue
         if f1 is None:
             fcl = filemerge.absentfilectx(wctx, fa)
         else:
             repo.ui.debug(" preserving %s for resolve of %s\n" % (f1, f))
             fcl = wctx[f1]
         if f2 is None:
             fco = filemerge.absentfilectx(mctx, fa)
         else:
             fco = mctx[f2]
         actx = repo[anc]
         if fa in actx:
             fca = actx[fa]
         else:
             # TODO: move to absentfilectx
             fca = repo.filectx(f1, fileid=nullrev)
         ms.add(fcl, fco, fca, f)
         if f1 != f and move:
             moves.append(f1)
 
-    _updating = _('updating')
-    _files = _('files')
-    progress = repo.ui.progress
-
     # remove renamed files after safely stored
     for f in moves:
         if wctx[f].lexists():
             repo.ui.debug("removing %s\n" % f)
             wctx[f].audit()
             wctx[f].remove()
 
     numupdates = sum(len(l) for m, l in actions.items()
                      if m != ACTION_KEEP)
-    z = 0
+    progress = repo.ui.makeprogress(_('updating'), unit=_('files'),
+                                    total=numupdates)
 
     if [a for a in actions[ACTION_REMOVE] if a[0] == '.hgsubstate']:
         subrepoutil.submerge(repo, wctx, mctx, wctx, overwrite, labels)
 
     # record path conflicts
     for f, args, msg in actions[ACTION_PATH_CONFLICT]:
         f1, fo = args
         s = repo.ui.status
         s(_("%s: path conflict - a file or link has the same name as a "
             "directory\n") % f)
         if fo == 'l':
             s(_("the local file has been renamed to %s\n") % f1)
         else:
             s(_("the remote file has been renamed to %s\n") % f1)
         s(_("resolve manually then use 'hg resolve --mark %s'\n") % f)
         ms.addpath(f, f1, fo)
-        z += 1
-        progress(_updating, z, item=f, total=numupdates, unit=_files)
+        progress.increment(item=f)
 
     # When merging in-memory, we can't support worker processes, so set the
     # per-item cost at 0 in that case.
     cost = 0 if wctx.isinmemory() else 0.001
 
     # remove in parallel (must come before resolving path conflicts and getting)
     prog = worker.worker(repo.ui, cost, batchremove, (repo, wctx),
                          actions[ACTION_REMOVE])
     for i, item in prog:
-        z += i
-        progress(_updating, z, item=item, total=numupdates, unit=_files)
+        progress.increment(step=i, item=item)
     removed = len(actions[ACTION_REMOVE])
 
     # resolve path conflicts (must come before getting)
     for f, args, msg in actions[ACTION_PATH_CONFLICT_RESOLVE]:
         repo.ui.debug(" %s: %s -> pr\n" % (f, msg))
         f0, = args
         if wctx[f0].lexists():
             repo.ui.note(_("moving %s to %s\n") % (f0, f))
             wctx[f].audit()
             wctx[f].write(wctx.filectx(f0).data(), wctx.filectx(f0).flags())
             wctx[f0].remove()
-        z += 1
-        progress(_updating, z, item=f, total=numupdates, unit=_files)
+        progress.increment(item=f)
 
     # get in parallel
     prog = worker.worker(repo.ui, cost, batchget, (repo, mctx, wctx),
                          actions[ACTION_GET])
     for i, item in prog:
-        z += i
-        progress(_updating, z, item=item, total=numupdates, unit=_files)
+        progress.increment(step=i, item=item)
     updated = len(actions[ACTION_GET])
 
     if [a for a in actions[ACTION_GET] if a[0] == '.hgsubstate']:
         subrepoutil.submerge(repo, wctx, mctx, wctx, overwrite, labels)
 
     # forget (manifest only, just log it) (must come first)
     for f, args, msg in actions[ACTION_FORGET]:
         repo.ui.debug(" %s: %s -> f\n" % (f, msg))
-        z += 1
-        progress(_updating, z, item=f, total=numupdates, unit=_files)
+        progress.increment(item=f)
 
     # re-add (manifest only, just log it)
     for f, args, msg in actions[ACTION_ADD]:
         repo.ui.debug(" %s: %s -> a\n" % (f, msg))
-        z += 1
-        progress(_updating, z, item=f, total=numupdates, unit=_files)
+        progress.increment(item=f)
 
     # re-add/mark as modified (manifest only, just log it)
     for f, args, msg in actions[ACTION_ADD_MODIFIED]:
         repo.ui.debug(" %s: %s -> am\n" % (f, msg))
-        z += 1
-        progress(_updating, z, item=f, total=numupdates, unit=_files)
+        progress.increment(item=f)
 
     # keep (noop, just log it)
     for f, args, msg in actions[ACTION_KEEP]:
         repo.ui.debug(" %s: %s -> k\n" % (f, msg))
         # no progress
 
     # directory rename, move local
     for f, args, msg in actions[ACTION_DIR_RENAME_MOVE_LOCAL]:
         repo.ui.debug(" %s: %s -> dm\n" % (f, msg))
-        z += 1
-        progress(_updating, z, item=f, total=numupdates, unit=_files)
+        progress.increment(item=f)
         f0, flags = args
         repo.ui.note(_("moving %s to %s\n") % (f0, f))
         wctx[f].audit()
         wctx[f].write(wctx.filectx(f0).data(), flags)
         wctx[f0].remove()
         updated += 1
 
     # local directory rename, get
     for f, args, msg in actions[ACTION_LOCAL_DIR_RENAME_GET]:
         repo.ui.debug(" %s: %s -> dg\n" % (f, msg))
-        z += 1
-        progress(_updating, z, item=f, total=numupdates, unit=_files)
+        progress.increment(item=f)
         f0, flags = args
         repo.ui.note(_("getting %s to %s\n") % (f0, f))
         wctx[f].write(mctx.filectx(f0).data(), flags)
         updated += 1
 
     # exec
     for f, args, msg in actions[ACTION_EXEC]:
         repo.ui.debug(" %s: %s -> e\n" % (f, msg))
-        z += 1
-        progress(_updating, z, item=f, total=numupdates, unit=_files)
+        progress.increment(item=f)
         flags, = args
         wctx[f].audit()
         wctx[f].setflags('l' in flags, 'x' in flags)
         updated += 1
 
     # the ordering is important here -- ms.mergedriver will raise if the merge
     # driver has changed, and we want to be able to bypass it when overwrite is
     # True
     usemergedriver = not overwrite and mergeactions and ms.mergedriver
 
     if usemergedriver:
         if wctx.isinmemory():
             raise error.InMemoryMergeConflictsError("in-memory merge does not "
                                                     "support mergedriver")
         ms.commit()
         proceed = driverpreprocess(repo, ms, wctx, labels=labels)
         # the driver might leave some files unresolved
         unresolvedf = set(ms.unresolved())
         if not proceed:
             # XXX setting unresolved to at least 1 is a hack to make sure we
             # error out
             return updateresult(updated, merged, removed,
                                 max(len(unresolvedf), 1))
         newactions = []
         for f, args, msg in mergeactions:
             if f in unresolvedf:
                 newactions.append((f, args, msg))
         mergeactions = newactions
 
     try:
         # premerge
         tocomplete = []
         for f, args, msg in mergeactions:
             repo.ui.debug(" %s: %s -> m (premerge)\n" % (f, msg))
-            z += 1
-            progress(_updating, z, item=f, total=numupdates, unit=_files)
+            progress.increment(item=f)
             if f == '.hgsubstate': # subrepo states need updating
                 subrepoutil.submerge(repo, wctx, mctx, wctx.ancestor(mctx),
                                      overwrite, labels)
                 continue
             wctx[f].audit()
             complete, r = ms.preresolve(f, wctx)
             if not complete:
                 numupdates += 1
                 tocomplete.append((f, args, msg))
 
         # merge
         for f, args, msg in tocomplete:
             repo.ui.debug(" %s: %s -> m (merge)\n" % (f, msg))
-            z += 1
-            progress(_updating, z, item=f, total=numupdates, unit=_files)
+            progress.increment(item=f, total=numupdates)
             ms.resolve(f, wctx)
 
     finally:
         ms.commit()
 
     unresolved = ms.unresolvedcount()
 
     if (usemergedriver and not unresolved
         and ms.mdstate() != MERGE_DRIVER_STATE_SUCCESS):
         if not driverconclude(repo, ms, wctx, labels=labels):
             # XXX setting unresolved to at least 1 is a hack to make sure we
             # error out
             unresolved = max(unresolved, 1)
 
         ms.commit()
 
     msupdated, msmerged, msremoved = ms.counts()
     updated += msupdated
     merged += msmerged
     removed += msremoved
 
     extraactions = ms.actions()
     if extraactions:
         mfiles = set(a[0] for a in actions[ACTION_MERGE])
         for k, acts in extraactions.iteritems():
             actions[k].extend(acts)
             # Remove these files from actions[ACTION_MERGE] as well. This is
             # important because in recordupdates, files in actions[ACTION_MERGE]
             # are processed after files in other actions, and the merge driver
             # might add files to those actions via extraactions above. This can
             # lead to a file being recorded twice, with poor results. This is
             # especially problematic for actions[ACTION_REMOVE] (currently only
             # possible with the merge driver in the initial merge process;
             # interrupted merges don't go through this flow).
             #
             # The real fix here is to have indexes by both file and action so
             # that when the action for a file is changed it is automatically
             # reflected in the other action lists. But that involves a more
             # complex data structure, so this will do for now.
             #
             # We don't need to do the same operation for 'dc' and 'cd' because
             # those lists aren't consulted again.
             mfiles.difference_update(a[0] for a in acts)
 
         actions[ACTION_MERGE] = [a for a in actions[ACTION_MERGE]
                                  if a[0] in mfiles]
 
-    progress(_updating, None, total=numupdates, unit=_files)
+    progress.update(None)
     return updateresult(updated, merged, removed, unresolved)
 
 def recordupdates(repo, actions, branchmerge):
     "record merge actions to the dirstate"
     # remove (must come first)
     for f, args, msg in actions.get(ACTION_REMOVE, []):
         if branchmerge:
             repo.dirstate.remove(f)
         else:
             repo.dirstate.drop(f)
 
     # forget (must come first)
     for f, args, msg in actions.get(ACTION_FORGET, []):
         repo.dirstate.drop(f)
 
     # resolve path conflicts
     for f, args, msg in actions.get(ACTION_PATH_CONFLICT_RESOLVE, []):
         f0, = args
         origf0 = repo.dirstate.copied(f0) or f0
         repo.dirstate.add(f)
         repo.dirstate.copy(origf0, f)
         if f0 == origf0:
             repo.dirstate.remove(f0)
         else:
             repo.dirstate.drop(f0)
 
     # re-add
     for f, args, msg in actions.get(ACTION_ADD, []):
         repo.dirstate.add(f)
 
     # re-add/mark as modified
     for f, args, msg in actions.get(ACTION_ADD_MODIFIED, []):
         if branchmerge:
             repo.dirstate.normallookup(f)
         else:
             repo.dirstate.add(f)
 
     # exec change
     for f, args, msg in actions.get(ACTION_EXEC, []):
         repo.dirstate.normallookup(f)
 
     # keep
     for f, args, msg in actions.get(ACTION_KEEP, []):
         pass
 
     # get
     for f, args, msg in actions.get(ACTION_GET, []):
         if branchmerge:
             repo.dirstate.otherparent(f)
         else:
             repo.dirstate.normal(f)
 
     # merge
     for f, args, msg in actions.get(ACTION_MERGE, []):
         f1, f2, fa, move, anc = args
         if branchmerge:
             # We've done a branch merge, mark this file as merged
             # so that we properly record the merger later
             repo.dirstate.merge(f)
             if f1 != f2: # copy/rename
                 if move:
                     repo.dirstate.remove(f1)
                 if f1 != f:
                     repo.dirstate.copy(f1, f)
                 else:
                     repo.dirstate.copy(f2, f)
         else:
             # We've update-merged a locally modified file, so
             # we set the dirstate to emulate a normal checkout
             # of that file some time in the past. Thus our
             # merge will appear as a normal local file
             # modification.
             if f2 == f: # file not locally copied/moved
                 repo.dirstate.normallookup(f)
             if move:
                 repo.dirstate.drop(f1)
 
     # directory rename, move local
     for f, args, msg in actions.get(ACTION_DIR_RENAME_MOVE_LOCAL, []):
         f0, flag = args
         if branchmerge:
             repo.dirstate.add(f)
             repo.dirstate.remove(f0)
             repo.dirstate.copy(f0, f)
         else:
             repo.dirstate.normal(f)
             repo.dirstate.drop(f0)
 
     # directory rename, get
     for f, args, msg in actions.get(ACTION_LOCAL_DIR_RENAME_GET, []):
         f0, flag = args
         if branchmerge:
             repo.dirstate.add(f)
             repo.dirstate.copy(f0, f)
         else:
             repo.dirstate.normal(f)
 
 def update(repo, node, branchmerge, force, ancestor=None,
            mergeancestor=False, labels=None, matcher=None, mergeforce=False,
            updatecheck=None, wc=None):
     """
     Perform a merge between the working directory and the given node
 
     node = the node to update to
     branchmerge = whether to merge between branches
     force = whether to force branch merging or file overwriting
     matcher = a matcher to filter file lists (dirstate not updated)
     mergeancestor = whether it is merging with an ancestor. If true,
       we should accept the incoming changes for any prompts that occur.
       If false, merging with an ancestor (fast-forward) is only allowed
       between different named branches. This flag is used by rebase extension
       as a temporary fix and should be avoided in general.
     labels = labels to use for base, local and other
     mergeforce = whether the merge was run with 'merge --force' (deprecated): if
       this is True, then 'force' should be True as well.
 
     The table below shows all the behaviors of the update command given the
     -c/--check and -C/--clean or no options, whether the working directory is
     dirty, whether a revision is specified, and the relationship of the parent
     rev to the target rev (linear or not). Match from top first. The -n
     option doesn't exist on the command line, but represents the
     experimental.updatecheck=noconflict option.
 
     This logic is tested by test-update-branches.t.
 
     -c  -C  -n  -m  dirty  rev  linear  |  result
      y   y   *   *    *     *     *     |    (1)
      y   *   y   *    *     *     *     |    (1)
      y   *   *   y    *     *     *     |    (1)
      *   y   y   *    *     *     *     |    (1)
      *   y   *   y    *     *     *     |    (1)
      *   *   y   y    *     *     *     |    (1)
      *   *   *   *    *     n     n     |     x
      *   *   *   *    n     *     *     |    ok
      n   n   n   n    y     *     y     |   merge
      n   n   n   n    y     y     n     |    (2)
      n   n   n   y    y     *     *     |   merge
      n   n   y   n    y     *     *     |  merge if no conflict
      n   y   n   n    y     *     *     |  discard
      y   n   n   n    y     *     *     |    (3)
 
     x = can't happen
     * = don't-care
     1 = incompatible options (checked in commands.py)
     2 = abort: uncommitted changes (commit or update --clean to discard changes)
     3 = abort: uncommitted changes (checked in commands.py)
 
     The merge is performed inside ``wc``, a workingctx-like objects. It defaults
     to repo[None] if None is passed.
 
     Return the same tuple as applyupdates().
     """
     # Avoid cycle.
     from . import sparse
 
     # This function used to find the default destination if node was None, but
     # that's now in destutil.py.
     assert node is not None
     if not branchmerge and not force:
         # TODO: remove the default once all callers that pass branchmerge=False
         # and force=False pass a value for updatecheck. We may want to allow
         # updatecheck='abort' to better suppport some of these callers.
         if updatecheck is None:
             updatecheck = 'linear'
         assert updatecheck in ('none', 'linear', 'noconflict')
     # If we're doing a partial update, we need to skip updating
     # the dirstate, so make a note of any partial-ness to the
     # update here.
     if matcher is None or matcher.always():
         partial = False
     else:
         partial = True
     with repo.wlock():
         if wc is None:
             wc = repo[None]
         pl = wc.parents()
         p1 = pl[0]
         pas = [None]
         if ancestor is not None:
             pas = [repo[ancestor]]
 
         overwrite = force and not branchmerge
 
         p2 = repo[node]
         if pas[0] is None:
             if repo.ui.configlist('merge', 'preferancestor') == ['*']:
                 cahs = repo.changelog.commonancestorsheads(p1.node(), p2.node())
                 pas = [repo[anc] for anc in (sorted(cahs) or [nullid])]
             else:
                 pas = [p1.ancestor(p2, warn=branchmerge)]
 
         fp1, fp2, xp1, xp2 = p1.node(), p2.node(), bytes(p1), bytes(p2)
 
         ### check phase
         if not overwrite:
             if len(pl) > 1:
                 raise error.Abort(_("outstanding uncommitted merge"))
             ms = mergestate.read(repo)
             if list(ms.unresolved()):
                 raise error.Abort(_("outstanding merge conflicts"))
         if branchmerge:
             if pas == [p2]:
                 raise error.Abort(_("merging with a working directory ancestor"
                                    " has no effect"))
             elif pas == [p1]:
                 if not mergeancestor and wc.branch() == p2.branch():
                     raise error.Abort(_("nothing to merge"),
                                      hint=_("use 'hg update' "
                                             "or check 'hg heads'"))
             if not force and (wc.files() or wc.deleted()):
                 raise error.Abort(_("uncommitted changes"),
                                  hint=_("use 'hg status' to list changes"))
             if not wc.isinmemory():
                 for s in sorted(wc.substate):
                     wc.sub(s).bailifchanged()
 
         elif not overwrite:
             if p1 == p2: # no-op update
                 # call the hooks and exit early
                 repo.hook('preupdate', throw=True, parent1=xp2, parent2='')
                 repo.hook('update', parent1=xp2, parent2='', error=0)
                 return updateresult(0, 0, 0, 0)
 
             if (updatecheck == 'linear' and
                     pas not in ([p1], [p2])):  # nonlinear
                 dirty = wc.dirty(missing=True)
                 if dirty:
                     # Branching is a bit strange to ensure we do the minimal
                     # amount of call to obsutil.foreground.
                     foreground = obsutil.foreground(repo, [p1.node()])
                     # note: the <node> variable contains a random identifier
                     if repo[node].node() in foreground:
                         pass # allow updating to successors
                     else:
                         msg = _("uncommitted changes")
                         hint = _("commit or update --clean to discard changes")
                         raise error.UpdateAbort(msg, hint=hint)
                 else:
                     # Allow jumping branches if clean and specific rev given
                     pass
 
         if overwrite:
             pas = [wc]
         elif not branchmerge:
             pas = [p1]
 
         # deprecated config: merge.followcopies
         followcopies = repo.ui.configbool('merge', 'followcopies')
         if overwrite:
             followcopies = False
         elif not pas[0]:
             followcopies = False
         if not branchmerge and not wc.dirty(missing=True):
             followcopies = False
 
         ### calculate phase
         actionbyfile, diverge, renamedelete = calculateupdates(
             repo, wc, p2, pas, branchmerge, force, mergeancestor,
             followcopies, matcher=matcher, mergeforce=mergeforce)
 
         if updatecheck == 'noconflict':
             for f, (m, args, msg) in actionbyfile.iteritems():
                 if m not in (ACTION_GET, ACTION_KEEP, ACTION_EXEC,
                              ACTION_REMOVE, ACTION_PATH_CONFLICT_RESOLVE):
                     msg = _("conflicting changes")
                     hint = _("commit or update --clean to discard changes")
                     raise error.Abort(msg, hint=hint)
 
         # Prompt and create actions. Most of this is in the resolve phase
         # already, but we can't handle .hgsubstate in filemerge or
         # subrepoutil.submerge yet so we have to keep prompting for it.
         if '.hgsubstate' in actionbyfile:
             f = '.hgsubstate'
             m, args, msg = actionbyfile[f]
             prompts = filemerge.partextras(labels)
             prompts['f'] = f
             if m == ACTION_CHANGED_DELETED:
                 if repo.ui.promptchoice(
                     _("local%(l)s changed %(f)s which other%(o)s deleted\n"
                       "use (c)hanged version or (d)elete?"
                       "$$ &Changed $$ &Delete") % prompts, 0):
                     actionbyfile[f] = (ACTION_REMOVE, None, 'prompt delete')
                 elif f in p1:
                     actionbyfile[f] = (ACTION_ADD_MODIFIED, None, 'prompt keep')
                 else:
                     actionbyfile[f] = (ACTION_ADD, None, 'prompt keep')
             elif m == ACTION_DELETED_CHANGED:
                 f1, f2, fa, move, anc = args
                 flags = p2[f2].flags()
                 if repo.ui.promptchoice(
                     _("other%(o)s changed %(f)s which local%(l)s deleted\n"
                       "use (c)hanged version or leave (d)eleted?"
                       "$$ &Changed $$ &Deleted") % prompts, 0) == 0:
                     actionbyfile[f] = (ACTION_GET, (flags, False),
                                        'prompt recreating')
                 else:
                     del actionbyfile[f]
 
         # Convert to dictionary-of-lists format
         actions = dict((m, [])
                        for m in (
                            ACTION_ADD,
                            ACTION_ADD_MODIFIED,
                            ACTION_FORGET,
                            ACTION_GET,
                            ACTION_CHANGED_DELETED,
                            ACTION_DELETED_CHANGED,
                            ACTION_REMOVE,
                            ACTION_DIR_RENAME_MOVE_LOCAL,
                            ACTION_LOCAL_DIR_RENAME_GET,
                            ACTION_MERGE,
                            ACTION_EXEC,
                            ACTION_KEEP,
                            ACTION_PATH_CONFLICT,
                            ACTION_PATH_CONFLICT_RESOLVE))
         for f, (m, args, msg) in actionbyfile.iteritems():
             if m not in actions:
                 actions[m] = []
             actions[m].append((f, args, msg))
 
         if not util.fscasesensitive(repo.path):
             # check collision between files only in p2 for clean update
             if (not branchmerge and
                 (force or not wc.dirty(missing=True, branch=False))):
                 _checkcollision(repo, p2.manifest(), None)
             else:
                 _checkcollision(repo, wc.manifest(), actions)
 
         # divergent renames
         for f, fl in sorted(diverge.iteritems()):
             repo.ui.warn(_("note: possible conflict - %s was renamed "
                            "multiple times to:\n") % f)
             for nf in fl:
                 repo.ui.warn(" %s\n" % nf)
 
         # rename and delete
         for f, fl in sorted(renamedelete.iteritems()):
             repo.ui.warn(_("note: possible conflict - %s was deleted "
                            "and renamed to:\n") % f)
             for nf in fl:
                 repo.ui.warn(" %s\n" % nf)
 
         ### apply phase
         if not branchmerge: # just jump to the new rev
             fp1, fp2, xp1, xp2 = fp2, nullid, xp2, ''
         if not partial and not wc.isinmemory():
             repo.hook('preupdate', throw=True, parent1=xp1, parent2=xp2)
             # note that we're in the middle of an update
             repo.vfs.write('updatestate', p2.hex())
 
         # Advertise fsmonitor when its presence could be useful.
         #
         # We only advertise when performing an update from an empty working
         # directory. This typically only occurs during initial clone.
         #
         # We give users a mechanism to disable the warning in case it is
         # annoying.
         #
         # We only allow on Linux and MacOS because that's where fsmonitor is
         # considered stable.
         fsmonitorwarning = repo.ui.configbool('fsmonitor', 'warn_when_unused')
         fsmonitorthreshold = repo.ui.configint('fsmonitor',
                                                'warn_update_file_count')
         try:
             # avoid cycle: extensions -> cmdutil -> merge
             from . import extensions
             extensions.find('fsmonitor')
             fsmonitorenabled = repo.ui.config('fsmonitor', 'mode') != 'off'
             # We intentionally don't look at whether fsmonitor has disabled
             # itself because a) fsmonitor may have already printed a warning
             # b) we only care about the config state here.
         except KeyError:
             fsmonitorenabled = False
 
         if (fsmonitorwarning
                 and not fsmonitorenabled
                 and p1.node() == nullid
                 and len(actions[ACTION_GET]) >= fsmonitorthreshold
                 and pycompat.sysplatform.startswith(('linux', 'darwin'))):
             repo.ui.warn(
                 _('(warning: large working directory being used without '
                   'fsmonitor enabled; enable fsmonitor to improve performance; '
                   'see "hg help -e fsmonitor")\n'))
 
         stats = applyupdates(repo, actions, wc, p2, overwrite, labels=labels)
 
         if not partial and not wc.isinmemory():
             with repo.dirstate.parentchange():
                 repo.setparents(fp1, fp2)
                 recordupdates(repo, actions, branchmerge)
                 # update completed, clear state
                 util.unlink(repo.vfs.join('updatestate'))
 
                 if not branchmerge:
                     repo.dirstate.setbranch(p2.branch())
 
     # If we're updating to a location, clean up any stale temporary includes
     # (ex: this happens during hg rebase --abort).
     if not branchmerge:
         sparse.prunetemporaryincludes(repo)
 
     if not partial:
         repo.hook('update', parent1=xp1, parent2=xp2,
                   error=stats.unresolvedcount)
     return stats
 
 def graft(repo, ctx, pctx, labels, keepparent=False):
     """Do a graft-like merge.
 
     This is a merge where the merge ancestor is chosen such that one
     or more changesets are grafted onto the current changeset. In
     addition to the merge, this fixes up the dirstate to include only
     a single parent (if keepparent is False) and tries to duplicate any
     renames/copies appropriately.
 
     ctx - changeset to rebase
     pctx - merge base, usually ctx.p1()
     labels - merge labels eg ['local', 'graft']
     keepparent - keep second parent if any
 
     """
     # If we're grafting a descendant onto an ancestor, be sure to pass
     # mergeancestor=True to update. This does two things: 1) allows the merge if
     # the destination is the same as the parent of the ctx (so we can use graft
     # to copy commits), and 2) informs update that the incoming changes are
     # newer than the destination so it doesn't prompt about "remote changed foo
     # which local deleted".
     mergeancestor = repo.changelog.isancestor(repo['.'].node(), ctx.node())
 
     stats = update(repo, ctx.node(), True, True, pctx.node(),
                    mergeancestor=mergeancestor, labels=labels)
 
     pother = nullid
     parents = ctx.parents()
     if keepparent and len(parents) == 2 and pctx in parents:
         parents.remove(pctx)
         pother = parents[0].node()
 
     with repo.dirstate.parentchange():
         repo.setparents(repo['.'].node(), pother)
         repo.dirstate.write(repo.currenttransaction())
         # fix up dirstate for copies and renames
         copies.duplicatecopies(repo, repo[None], ctx.rev(), pctx.rev())
     return stats

mercurial/scmutil.py

@@ -1,1615 +1,1636 b''
 # scmutil.py - Mercurial core utility functions
 #
 #  Copyright Matt 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.
 
 from __future__ import absolute_import
 
 import errno
 import glob
 import hashlib
 import os
 import re
 import socket
 import subprocess
 import weakref
 
 from .i18n import _
 from .node import (
     bin,
     hex,
     nullid,
     short,
     wdirid,
     wdirrev,
 )
 
 from . import (
     encoding,
     error,
     match as matchmod,
     obsolete,
     obsutil,
     pathutil,
     phases,
     pycompat,
     revsetlang,
     similar,
     url,
     util,
     vfs,
 )
 
 from .utils import (
     procutil,
     stringutil,
 )
 
 if pycompat.iswindows:
     from . import scmwindows as scmplatform
 else:
     from . import scmposix as scmplatform
 
 termsize = scmplatform.termsize
 
 class status(tuple):
     '''Named tuple with a list of files per status. The 'deleted', 'unknown'
        and 'ignored' properties are only relevant to the working copy.
     '''
 
     __slots__ = ()
 
     def __new__(cls, modified, added, removed, deleted, unknown, ignored,
                 clean):
         return tuple.__new__(cls, (modified, added, removed, deleted, unknown,
                                    ignored, clean))
 
     @property
     def modified(self):
         '''files that have been modified'''
         return self[0]
 
     @property
     def added(self):
         '''files that have been added'''
         return self[1]
 
     @property
     def removed(self):
         '''files that have been removed'''
         return self[2]
 
     @property
     def deleted(self):
         '''files that are in the dirstate, but have been deleted from the
            working copy (aka "missing")
         '''
         return self[3]
 
     @property
     def unknown(self):
         '''files not in the dirstate that are not ignored'''
         return self[4]
 
     @property
     def ignored(self):
         '''files not in the dirstate that are ignored (by _dirignore())'''
         return self[5]
 
     @property
     def clean(self):
         '''files that have not been modified'''
         return self[6]
 
     def __repr__(self, *args, **kwargs):
         return ((r'<status modified=%s, added=%s, removed=%s, deleted=%s, '
                  r'unknown=%s, ignored=%s, clean=%s>') %
                 tuple(pycompat.sysstr(stringutil.pprint(v)) for v in self))
 
 def itersubrepos(ctx1, ctx2):
     """find subrepos in ctx1 or ctx2"""
     # Create a (subpath, ctx) mapping where we prefer subpaths from
     # ctx1. The subpaths from ctx2 are important when the .hgsub file
     # has been modified (in ctx2) but not yet committed (in ctx1).
     subpaths = dict.fromkeys(ctx2.substate, ctx2)
     subpaths.update(dict.fromkeys(ctx1.substate, ctx1))
 
     missing = set()
 
     for subpath in ctx2.substate:
         if subpath not in ctx1.substate:
             del subpaths[subpath]
             missing.add(subpath)
 
     for subpath, ctx in sorted(subpaths.iteritems()):
         yield subpath, ctx.sub(subpath)
 
     # Yield an empty subrepo based on ctx1 for anything only in ctx2.  That way,
     # status and diff will have an accurate result when it does
     # 'sub.{status|diff}(rev2)'.  Otherwise, the ctx2 subrepo is compared
     # against itself.
     for subpath in missing:
         yield subpath, ctx2.nullsub(subpath, ctx1)
 
 def nochangesfound(ui, repo, excluded=None):
     '''Report no changes for push/pull, excluded is None or a list of
     nodes excluded from the push/pull.
     '''
     secretlist = []
     if excluded:
         for n in excluded:
             ctx = repo[n]
             if ctx.phase() >= phases.secret and not ctx.extinct():
                 secretlist.append(n)
 
     if secretlist:
         ui.status(_("no changes found (ignored %d secret changesets)\n")
                   % len(secretlist))
     else:
         ui.status(_("no changes found\n"))
 
 def callcatch(ui, func):
     """call func() with global exception handling
 
     return func() if no exception happens. otherwise do some error handling
     and return an exit code accordingly. does not handle all exceptions.
     """
     try:
         try:
             return func()
         except: # re-raises
             ui.traceback()
             raise
     # Global exception handling, alphabetically
     # Mercurial-specific first, followed by built-in and library exceptions
     except error.LockHeld as inst:
         if inst.errno == errno.ETIMEDOUT:
             reason = _('timed out waiting for lock held by %r') % inst.locker
         else:
             reason = _('lock held by %r') % inst.locker
         ui.warn(_("abort: %s: %s\n")
                 % (inst.desc or stringutil.forcebytestr(inst.filename), reason))
         if not inst.locker:
             ui.warn(_("(lock might be very busy)\n"))
     except error.LockUnavailable as inst:
         ui.warn(_("abort: could not lock %s: %s\n") %
                 (inst.desc or stringutil.forcebytestr(inst.filename),
                  encoding.strtolocal(inst.strerror)))
     except error.OutOfBandError as inst:
         if inst.args:
             msg = _("abort: remote error:\n")
         else:
             msg = _("abort: remote error\n")
         ui.warn(msg)
         if inst.args:
             ui.warn(''.join(inst.args))
         if inst.hint:
             ui.warn('(%s)\n' % inst.hint)
     except error.RepoError as inst:
         ui.warn(_("abort: %s!\n") % inst)
         if inst.hint:
             ui.warn(_("(%s)\n") % inst.hint)
     except error.ResponseError as inst:
         ui.warn(_("abort: %s") % inst.args[0])
         msg = inst.args[1]
         if isinstance(msg, type(u'')):
             msg = pycompat.sysbytes(msg)
         if not isinstance(msg, bytes):
             ui.warn(" %r\n" % (msg,))
         elif not msg:
             ui.warn(_(" empty string\n"))
         else:
             ui.warn("\n%r\n" % stringutil.ellipsis(msg))
     except error.CensoredNodeError as inst:
         ui.warn(_("abort: file censored %s!\n") % inst)
     except error.RevlogError as inst:
         ui.warn(_("abort: %s!\n") % inst)
     except error.InterventionRequired as inst:
         ui.warn("%s\n" % inst)
         if inst.hint:
             ui.warn(_("(%s)\n") % inst.hint)
         return 1
     except error.WdirUnsupported:
         ui.warn(_("abort: working directory revision cannot be specified\n"))
     except error.Abort as inst:
         ui.warn(_("abort: %s\n") % inst)
         if inst.hint:
             ui.warn(_("(%s)\n") % inst.hint)
     except ImportError as inst:
         ui.warn(_("abort: %s!\n") % stringutil.forcebytestr(inst))
         m = stringutil.forcebytestr(inst).split()[-1]
         if m in "mpatch bdiff".split():
             ui.warn(_("(did you forget to compile extensions?)\n"))
         elif m in "zlib".split():
             ui.warn(_("(is your Python install correct?)\n"))
     except IOError as inst:
         if util.safehasattr(inst, "code"):
             ui.warn(_("abort: %s\n") % stringutil.forcebytestr(inst))
         elif util.safehasattr(inst, "reason"):
             try: # usually it is in the form (errno, strerror)
                 reason = inst.reason.args[1]
             except (AttributeError, IndexError):
                 # it might be anything, for example a string
                 reason = inst.reason
             if isinstance(reason, pycompat.unicode):
                 # SSLError of Python 2.7.9 contains a unicode
                 reason = encoding.unitolocal(reason)
             ui.warn(_("abort: error: %s\n") % reason)
         elif (util.safehasattr(inst, "args")
               and inst.args and inst.args[0] == errno.EPIPE):
             pass
         elif getattr(inst, "strerror", None):
             if getattr(inst, "filename", None):
                 ui.warn(_("abort: %s: %s\n") % (
                     encoding.strtolocal(inst.strerror),
                     stringutil.forcebytestr(inst.filename)))
             else:
                 ui.warn(_("abort: %s\n") % encoding.strtolocal(inst.strerror))
         else:
             raise
     except OSError as inst:
         if getattr(inst, "filename", None) is not None:
             ui.warn(_("abort: %s: '%s'\n") % (
                 encoding.strtolocal(inst.strerror),
                 stringutil.forcebytestr(inst.filename)))
         else:
             ui.warn(_("abort: %s\n") % encoding.strtolocal(inst.strerror))
     except MemoryError:
         ui.warn(_("abort: out of memory\n"))
     except SystemExit as inst:
         # Commands shouldn't sys.exit directly, but give a return code.
         # Just in case catch this and and pass exit code to caller.
         return inst.code
     except socket.error as inst:
         ui.warn(_("abort: %s\n") % stringutil.forcebytestr(inst.args[-1]))
 
     return -1
 
 def checknewlabel(repo, lbl, kind):
     # Do not use the "kind" parameter in ui output.
     # It makes strings difficult to translate.
     if lbl in ['tip', '.', 'null']:
         raise error.Abort(_("the name '%s' is reserved") % lbl)
     for c in (':', '\0', '\n', '\r'):
         if c in lbl:
             raise error.Abort(
                 _("%r cannot be used in a name") % pycompat.bytestr(c))
     try:
         int(lbl)
         raise error.Abort(_("cannot use an integer as a name"))
     except ValueError:
         pass
     if lbl.strip() != lbl:
         raise error.Abort(_("leading or trailing whitespace in name %r") % lbl)
 
 def checkfilename(f):
     '''Check that the filename f is an acceptable filename for a tracked file'''
     if '\r' in f or '\n' in f:
         raise error.Abort(_("'\\n' and '\\r' disallowed in filenames: %r")
                           % pycompat.bytestr(f))
 
 def checkportable(ui, f):
     '''Check if filename f is portable and warn or abort depending on config'''
     checkfilename(f)
     abort, warn = checkportabilityalert(ui)
     if abort or warn:
         msg = util.checkwinfilename(f)
         if msg:
             msg = "%s: %s" % (msg, procutil.shellquote(f))
             if abort:
                 raise error.Abort(msg)
             ui.warn(_("warning: %s\n") % msg)
 
 def checkportabilityalert(ui):
     '''check if the user's config requests nothing, a warning, or abort for
     non-portable filenames'''
     val = ui.config('ui', 'portablefilenames')
     lval = val.lower()
     bval = stringutil.parsebool(val)
     abort = pycompat.iswindows or lval == 'abort'
     warn = bval or lval == 'warn'
     if bval is None and not (warn or abort or lval == 'ignore'):
         raise error.ConfigError(
             _("ui.portablefilenames value is invalid ('%s')") % val)
     return abort, warn
 
 class casecollisionauditor(object):
     def __init__(self, ui, abort, dirstate):
         self._ui = ui
         self._abort = abort
         allfiles = '\0'.join(dirstate._map)
         self._loweredfiles = set(encoding.lower(allfiles).split('\0'))
         self._dirstate = dirstate
         # The purpose of _newfiles is so that we don't complain about
         # case collisions if someone were to call this object with the
         # same filename twice.
         self._newfiles = set()
 
     def __call__(self, f):
         if f in self._newfiles:
             return
         fl = encoding.lower(f)
         if fl in self._loweredfiles and f not in self._dirstate:
             msg = _('possible case-folding collision for %s') % f
             if self._abort:
                 raise error.Abort(msg)
             self._ui.warn(_("warning: %s\n") % msg)
         self._loweredfiles.add(fl)
         self._newfiles.add(f)
 
 def filteredhash(repo, maxrev):
     """build hash of filtered revisions in the current repoview.
 
     Multiple caches perform up-to-date validation by checking that the
     tiprev and tipnode stored in the cache file match the current repository.
     However, this is not sufficient for validating repoviews because the set
     of revisions in the view may change without the repository tiprev and
     tipnode changing.
 
     This function hashes all the revs filtered from the view and returns
     that SHA-1 digest.
     """
     cl = repo.changelog
     if not cl.filteredrevs:
         return None
     key = None
     revs = sorted(r for r in cl.filteredrevs if r <= maxrev)
     if revs:
         s = hashlib.sha1()
         for rev in revs:
             s.update('%d;' % rev)
         key = s.digest()
     return key
 
 def walkrepos(path, followsym=False, seen_dirs=None, recurse=False):
     '''yield every hg repository under path, always recursively.
     The recurse flag will only control recursion into repo working dirs'''
     def errhandler(err):
         if err.filename == path:
             raise err
     samestat = getattr(os.path, 'samestat', None)
     if followsym and samestat is not None:
         def adddir(dirlst, dirname):
             dirstat = os.stat(dirname)
             match = any(samestat(dirstat, lstdirstat) for lstdirstat in dirlst)
             if not match:
                 dirlst.append(dirstat)
             return not match
     else:
         followsym = False
 
     if (seen_dirs is None) and followsym:
         seen_dirs = []
         adddir(seen_dirs, path)
     for root, dirs, files in os.walk(path, topdown=True, onerror=errhandler):
         dirs.sort()
         if '.hg' in dirs:
             yield root # found a repository
             qroot = os.path.join(root, '.hg', 'patches')
             if os.path.isdir(os.path.join(qroot, '.hg')):
                 yield qroot # we have a patch queue repo here
             if recurse:
                 # avoid recursing inside the .hg directory
                 dirs.remove('.hg')
             else:
                 dirs[:] = [] # don't descend further
         elif followsym:
             newdirs = []
             for d in dirs:
                 fname = os.path.join(root, d)
                 if adddir(seen_dirs, fname):
                     if os.path.islink(fname):
                         for hgname in walkrepos(fname, True, seen_dirs):
                             yield hgname
                     else:
                         newdirs.append(d)
             dirs[:] = newdirs
 
 def binnode(ctx):
     """Return binary node id for a given basectx"""
     node = ctx.node()
     if node is None:
         return wdirid
     return node
 
 def intrev(ctx):
     """Return integer for a given basectx that can be used in comparison or
     arithmetic operation"""
     rev = ctx.rev()
     if rev is None:
         return wdirrev
     return rev
 
 def formatchangeid(ctx):
     """Format changectx as '{rev}:{node|formatnode}', which is the default
     template provided by logcmdutil.changesettemplater"""
     repo = ctx.repo()
     return formatrevnode(repo.ui, intrev(ctx), binnode(ctx))
 
 def formatrevnode(ui, rev, node):
     """Format given revision and node depending on the current verbosity"""
     if ui.debugflag:
         hexfunc = hex
     else:
         hexfunc = short
     return '%d:%s' % (rev, hexfunc(node))
 
 def resolvehexnodeidprefix(repo, prefix):
     # Uses unfiltered repo because it's faster when prefix is ambiguous/
     # This matches the shortesthexnodeidprefix() function below.
     node = repo.unfiltered().changelog._partialmatch(prefix)
     if node is None:
         return
     repo.changelog.rev(node)  # make sure node isn't filtered
     return node
 
 def shortesthexnodeidprefix(repo, node, minlength=1):
     """Find the shortest unambiguous prefix that matches hexnode."""
     # _partialmatch() of filtered changelog could take O(len(repo)) time,
     # which would be unacceptably slow. so we look for hash collision in
     # unfiltered space, which means some hashes may be slightly longer.
     cl = repo.unfiltered().changelog
 
     def isrev(prefix):
         try:
             i = int(prefix)
             # if we are a pure int, then starting with zero will not be
             # confused as a rev; or, obviously, if the int is larger
             # than the value of the tip rev
             if prefix[0] == '0' or i > len(cl):
                 return False
             return True
         except ValueError:
             return False
 
     def disambiguate(prefix):
         """Disambiguate against revnums."""
         hexnode = hex(node)
         for length in range(len(prefix), len(hexnode) + 1):
             prefix = hexnode[:length]
             if not isrev(prefix):
                 return prefix
 
     try:
         return disambiguate(cl.shortest(node, minlength))
     except error.LookupError:
         raise error.RepoLookupError()
 
 def isrevsymbol(repo, symbol):
     """Checks if a symbol exists in the repo.
 
     See revsymbol() for details. Raises error.LookupError if the symbol is an
     ambiguous nodeid prefix.
     """
     try:
         revsymbol(repo, symbol)
         return True
     except error.RepoLookupError:
         return False
 
 def revsymbol(repo, symbol):
     """Returns a context given a single revision symbol (as string).
 
     This is similar to revsingle(), but accepts only a single revision symbol,
     i.e. things like ".", "tip", "1234", "deadbeef", "my-bookmark" work, but
     not "max(public())".
     """
     if not isinstance(symbol, bytes):
         msg = ("symbol (%s of type %s) was not a string, did you mean "
                "repo[symbol]?" % (symbol, type(symbol)))
         raise error.ProgrammingError(msg)
     try:
         if symbol in ('.', 'tip', 'null'):
             return repo[symbol]
 
         try:
             r = int(symbol)
             if '%d' % r != symbol:
                 raise ValueError
             l = len(repo.changelog)
             if r < 0:
                 r += l
             if r < 0 or r >= l and r != wdirrev:
                 raise ValueError
             return repo[r]
         except error.FilteredIndexError:
             raise
         except (ValueError, OverflowError, IndexError):
             pass
 
         if len(symbol) == 40:
             try:
                 node = bin(symbol)
                 rev = repo.changelog.rev(node)
                 return repo[rev]
             except error.FilteredLookupError:
                 raise
             except (TypeError, LookupError):
                 pass
 
         # look up bookmarks through the name interface
         try:
             node = repo.names.singlenode(repo, symbol)
             rev = repo.changelog.rev(node)
             return repo[rev]
         except KeyError:
             pass
 
         node = resolvehexnodeidprefix(repo, symbol)
         if node is not None:
             rev = repo.changelog.rev(node)
             return repo[rev]
 
         raise error.RepoLookupError(_("unknown revision '%s'") % symbol)
 
     except error.WdirUnsupported:
         return repo[None]
     except (error.FilteredIndexError, error.FilteredLookupError,
             error.FilteredRepoLookupError):
         raise _filterederror(repo, symbol)
 
 def _filterederror(repo, changeid):
     """build an exception to be raised about a filtered changeid
 
     This is extracted in a function to help extensions (eg: evolve) to
     experiment with various message variants."""
     if repo.filtername.startswith('visible'):
 
         # Check if the changeset is obsolete
         unfilteredrepo = repo.unfiltered()
         ctx = revsymbol(unfilteredrepo, changeid)
 
         # If the changeset is obsolete, enrich the message with the reason
         # that made this changeset not visible
         if ctx.obsolete():
             msg = obsutil._getfilteredreason(repo, changeid, ctx)
         else:
             msg = _("hidden revision '%s'") % changeid
 
         hint = _('use --hidden to access hidden revisions')
 
         return error.FilteredRepoLookupError(msg, hint=hint)
     msg = _("filtered revision '%s' (not in '%s' subset)")
     msg %= (changeid, repo.filtername)
     return error.FilteredRepoLookupError(msg)
 
 def revsingle(repo, revspec, default='.', localalias=None):
     if not revspec and revspec != 0:
         return repo[default]
 
     l = revrange(repo, [revspec], localalias=localalias)
     if not l:
         raise error.Abort(_('empty revision set'))
     return repo[l.last()]
 
 def _pairspec(revspec):
     tree = revsetlang.parse(revspec)
     return tree and tree[0] in ('range', 'rangepre', 'rangepost', 'rangeall')
 
 def revpair(repo, revs):
     if not revs:
         return repo['.'], repo[None]
 
     l = revrange(repo, revs)
 
     if not l:
         first = second = None
     elif l.isascending():
         first = l.min()
         second = l.max()
     elif l.isdescending():
         first = l.max()
         second = l.min()
     else:
         first = l.first()
         second = l.last()
 
     if first is None:
         raise error.Abort(_('empty revision range'))
     if (first == second and len(revs) >= 2
         and not all(revrange(repo, [r]) for r in revs)):
         raise error.Abort(_('empty revision on one side of range'))
 
     # if top-level is range expression, the result must always be a pair
     if first == second and len(revs) == 1 and not _pairspec(revs[0]):
         return repo[first], repo[None]
 
     return repo[first], repo[second]
 
 def revrange(repo, specs, localalias=None):
     """Execute 1 to many revsets and return the union.
 
     This is the preferred mechanism for executing revsets using user-specified
     config options, such as revset aliases.
 
     The revsets specified by ``specs`` will be executed via a chained ``OR``
     expression. If ``specs`` is empty, an empty result is returned.
 
     ``specs`` can contain integers, in which case they are assumed to be
     revision numbers.
 
     It is assumed the revsets are already formatted. If you have arguments
     that need to be expanded in the revset, call ``revsetlang.formatspec()``
     and pass the result as an element of ``specs``.
 
     Specifying a single revset is allowed.
 
     Returns a ``revset.abstractsmartset`` which is a list-like interface over
     integer revisions.
     """
     allspecs = []
     for spec in specs:
         if isinstance(spec, int):
             spec = revsetlang.formatspec('rev(%d)', spec)
         allspecs.append(spec)
     return repo.anyrevs(allspecs, user=True, localalias=localalias)
 
 def meaningfulparents(repo, ctx):
     """Return list of meaningful (or all if debug) parentrevs for rev.
 
     For merges (two non-nullrev revisions) both parents are meaningful.
     Otherwise the first parent revision is considered meaningful if it
     is not the preceding revision.
     """
     parents = ctx.parents()
     if len(parents) > 1:
         return parents
     if repo.ui.debugflag:
         return [parents[0], repo['null']]
     if parents[0].rev() >= intrev(ctx) - 1:
         return []
     return parents
 
 def expandpats(pats):
     '''Expand bare globs when running on windows.
     On posix we assume it already has already been done by sh.'''
     if not util.expandglobs:
         return list(pats)
     ret = []
     for kindpat in pats:
         kind, pat = matchmod._patsplit(kindpat, None)
         if kind is None:
             try:
                 globbed = glob.glob(pat)
             except re.error:
                 globbed = [pat]
             if globbed:
                 ret.extend(globbed)
                 continue
         ret.append(kindpat)
     return ret
 
 def matchandpats(ctx, pats=(), opts=None, globbed=False, default='relpath',
                  badfn=None):
     '''Return a matcher and the patterns that were used.
     The matcher will warn about bad matches, unless an alternate badfn callback
     is provided.'''
     if pats == ("",):
         pats = []
     if opts is None:
         opts = {}
     if not globbed and default == 'relpath':
         pats = expandpats(pats or [])
 
     def bad(f, msg):
         ctx.repo().ui.warn("%s: %s\n" % (m.rel(f), msg))
 
     if badfn is None:
         badfn = bad
 
     m = ctx.match(pats, opts.get('include'), opts.get('exclude'),
                   default, listsubrepos=opts.get('subrepos'), badfn=badfn)
 
     if m.always():
         pats = []
     return m, pats
 
 def match(ctx, pats=(), opts=None, globbed=False, default='relpath',
           badfn=None):
     '''Return a matcher that will warn about bad matches.'''
     return matchandpats(ctx, pats, opts, globbed, default, badfn=badfn)[0]
 
 def matchall(repo):
     '''Return a matcher that will efficiently match everything.'''
     return matchmod.always(repo.root, repo.getcwd())
 
 def matchfiles(repo, files, badfn=None):
     '''Return a matcher that will efficiently match exactly these files.'''
     return matchmod.exact(repo.root, repo.getcwd(), files, badfn=badfn)
 
 def parsefollowlinespattern(repo, rev, pat, msg):
     """Return a file name from `pat` pattern suitable for usage in followlines
     logic.
     """
     if not matchmod.patkind(pat):
         return pathutil.canonpath(repo.root, repo.getcwd(), pat)
     else:
         ctx = repo[rev]
         m = matchmod.match(repo.root, repo.getcwd(), [pat], ctx=ctx)
         files = [f for f in ctx if m(f)]
         if len(files) != 1:
             raise error.ParseError(msg)
         return files[0]
 
 def origpath(ui, repo, filepath):
     '''customize where .orig files are created
 
     Fetch user defined path from config file: [ui] origbackuppath = <path>
     Fall back to default (filepath with .orig suffix) if not specified
     '''
     origbackuppath = ui.config('ui', 'origbackuppath')
     if not origbackuppath:
         return filepath + ".orig"
 
     # Convert filepath from an absolute path into a path inside the repo.
     filepathfromroot = util.normpath(os.path.relpath(filepath,
                                                      start=repo.root))
 
     origvfs = vfs.vfs(repo.wjoin(origbackuppath))
     origbackupdir = origvfs.dirname(filepathfromroot)
     if not origvfs.isdir(origbackupdir) or origvfs.islink(origbackupdir):
         ui.note(_('creating directory: %s\n') % origvfs.join(origbackupdir))
 
         # Remove any files that conflict with the backup file's path
         for f in reversed(list(util.finddirs(filepathfromroot))):
             if origvfs.isfileorlink(f):
                 ui.note(_('removing conflicting file: %s\n')
                         % origvfs.join(f))
                 origvfs.unlink(f)
                 break
 
         origvfs.makedirs(origbackupdir)
 
     if origvfs.isdir(filepathfromroot) and not origvfs.islink(filepathfromroot):
         ui.note(_('removing conflicting directory: %s\n')
                 % origvfs.join(filepathfromroot))
         origvfs.rmtree(filepathfromroot, forcibly=True)
 
     return origvfs.join(filepathfromroot)
 
 class _containsnode(object):
     """proxy __contains__(node) to container.__contains__ which accepts revs"""
 
     def __init__(self, repo, revcontainer):
         self._torev = repo.changelog.rev
         self._revcontains = revcontainer.__contains__
 
     def __contains__(self, node):
         return self._revcontains(self._torev(node))
 
 def cleanupnodes(repo, replacements, operation, moves=None, metadata=None):
     """do common cleanups when old nodes are replaced by new nodes
 
     That includes writing obsmarkers or stripping nodes, and moving bookmarks.
     (we might also want to move working directory parent in the future)
 
     By default, bookmark moves are calculated automatically from 'replacements',
     but 'moves' can be used to override that. Also, 'moves' may include
     additional bookmark moves that should not have associated obsmarkers.
 
     replacements is {oldnode: [newnode]} or a iterable of nodes if they do not
     have replacements. operation is a string, like "rebase".
 
     metadata is dictionary containing metadata to be stored in obsmarker if
     obsolescence is enabled.
     """
     if not replacements and not moves:
         return
 
     # translate mapping's other forms
     if not util.safehasattr(replacements, 'items'):
         replacements = {n: () for n in replacements}
 
     # Calculate bookmark movements
     if moves is None:
         moves = {}
     # Unfiltered repo is needed since nodes in replacements might be hidden.
     unfi = repo.unfiltered()
     for oldnode, newnodes in replacements.items():
         if oldnode in moves:
             continue
         if len(newnodes) > 1:
             # usually a split, take the one with biggest rev number
             newnode = next(unfi.set('max(%ln)', newnodes)).node()
         elif len(newnodes) == 0:
             # move bookmark backwards
             roots = list(unfi.set('max((::%n) - %ln)', oldnode,
                                   list(replacements)))
             if roots:
                 newnode = roots[0].node()
             else:
                 newnode = nullid
         else:
             newnode = newnodes[0]
         moves[oldnode] = newnode
 
     with repo.transaction('cleanup') as tr:
         # Move bookmarks
         bmarks = repo._bookmarks
         bmarkchanges = []
         allnewnodes = [n for ns in replacements.values() for n in ns]
         for oldnode, newnode in moves.items():
             oldbmarks = repo.nodebookmarks(oldnode)
             if not oldbmarks:
                 continue
             from . import bookmarks # avoid import cycle
             repo.ui.debug('moving bookmarks %r from %s to %s\n' %
                           (util.rapply(pycompat.maybebytestr, oldbmarks),
                            hex(oldnode), hex(newnode)))
             # Delete divergent bookmarks being parents of related newnodes
             deleterevs = repo.revs('parents(roots(%ln & (::%n))) - parents(%n)',
                                    allnewnodes, newnode, oldnode)
             deletenodes = _containsnode(repo, deleterevs)
             for name in oldbmarks:
                 bmarkchanges.append((name, newnode))
                 for b in bookmarks.divergent2delete(repo, deletenodes, name):
                     bmarkchanges.append((b, None))
 
         if bmarkchanges:
             bmarks.applychanges(repo, tr, bmarkchanges)
 
         # Obsolete or strip nodes
         if obsolete.isenabled(repo, obsolete.createmarkersopt):
             # If a node is already obsoleted, and we want to obsolete it
             # without a successor, skip that obssolete request since it's
             # unnecessary. That's the "if s or not isobs(n)" check below.
             # Also sort the node in topology order, that might be useful for
             # some obsstore logic.
             # NOTE: the filtering and sorting might belong to createmarkers.
             isobs = unfi.obsstore.successors.__contains__
             torev = unfi.changelog.rev
             sortfunc = lambda ns: torev(ns[0])
             rels = [(unfi[n], tuple(unfi[m] for m in s))
                     for n, s in sorted(replacements.items(), key=sortfunc)
                     if s or not isobs(n)]
             if rels:
                 obsolete.createmarkers(repo, rels, operation=operation,
                                        metadata=metadata)
         else:
             from . import repair # avoid import cycle
             tostrip = list(replacements)
             if tostrip:
                 repair.delayedstrip(repo.ui, repo, tostrip, operation)
 
 def addremove(repo, matcher, prefix, opts=None):
     if opts is None:
         opts = {}
     m = matcher
     dry_run = opts.get('dry_run')
     try:
         similarity = float(opts.get('similarity') or 0)
     except ValueError:
         raise error.Abort(_('similarity must be a number'))
     if similarity < 0 or similarity > 100:
         raise error.Abort(_('similarity must be between 0 and 100'))
     similarity /= 100.0
 
     ret = 0
     join = lambda f: os.path.join(prefix, f)
 
     wctx = repo[None]
     for subpath in sorted(wctx.substate):
         submatch = matchmod.subdirmatcher(subpath, m)
         if opts.get('subrepos') or m.exact(subpath) or any(submatch.files()):
             sub = wctx.sub(subpath)
             try:
                 if sub.addremove(submatch, prefix, opts):
                     ret = 1
             except error.LookupError:
                 repo.ui.status(_("skipping missing subrepository: %s\n")
                                  % join(subpath))
 
     rejected = []
     def badfn(f, msg):
         if f in m.files():
             m.bad(f, msg)
         rejected.append(f)
 
     badmatch = matchmod.badmatch(m, badfn)
     added, unknown, deleted, removed, forgotten = _interestingfiles(repo,
                                                                     badmatch)
 
     unknownset = set(unknown + forgotten)
     toprint = unknownset.copy()
     toprint.update(deleted)
     for abs in sorted(toprint):
         if repo.ui.verbose or not m.exact(abs):
             if abs in unknownset:
                 status = _('adding %s\n') % m.uipath(abs)
             else:
                 status = _('removing %s\n') % m.uipath(abs)
             repo.ui.status(status)
 
     renames = _findrenames(repo, m, added + unknown, removed + deleted,
                            similarity)
 
     if not dry_run:
         _markchanges(repo, unknown + forgotten, deleted, renames)
 
     for f in rejected:
         if f in m.files():
             return 1
     return ret
 
 def marktouched(repo, files, similarity=0.0):
     '''Assert that files have somehow been operated upon. files are relative to
     the repo root.'''
     m = matchfiles(repo, files, badfn=lambda x, y: rejected.append(x))
     rejected = []
 
     added, unknown, deleted, removed, forgotten = _interestingfiles(repo, m)
 
     if repo.ui.verbose:
         unknownset = set(unknown + forgotten)
         toprint = unknownset.copy()
         toprint.update(deleted)
         for abs in sorted(toprint):
             if abs in unknownset:
                 status = _('adding %s\n') % abs
             else:
                 status = _('removing %s\n') % abs
             repo.ui.status(status)
 
     renames = _findrenames(repo, m, added + unknown, removed + deleted,
                            similarity)
 
     _markchanges(repo, unknown + forgotten, deleted, renames)
 
     for f in rejected:
         if f in m.files():
             return 1
     return 0
 
 def _interestingfiles(repo, matcher):
     '''Walk dirstate with matcher, looking for files that addremove would care
     about.
 
     This is different from dirstate.status because it doesn't care about
     whether files are modified or clean.'''
     added, unknown, deleted, removed, forgotten = [], [], [], [], []
     audit_path = pathutil.pathauditor(repo.root, cached=True)
 
     ctx = repo[None]
     dirstate = repo.dirstate
     walkresults = dirstate.walk(matcher, subrepos=sorted(ctx.substate),
                                 unknown=True, ignored=False, full=False)
     for abs, st in walkresults.iteritems():
         dstate = dirstate[abs]
         if dstate == '?' and audit_path.check(abs):
             unknown.append(abs)
         elif dstate != 'r' and not st:
             deleted.append(abs)
         elif dstate == 'r' and st:
             forgotten.append(abs)
         # for finding renames
         elif dstate == 'r' and not st:
             removed.append(abs)
         elif dstate == 'a':
             added.append(abs)
 
     return added, unknown, deleted, removed, forgotten
 
 def _findrenames(repo, matcher, added, removed, similarity):
     '''Find renames from removed files to added ones.'''
     renames = {}
     if similarity > 0:
         for old, new, score in similar.findrenames(repo, added, removed,
                                                    similarity):
             if (repo.ui.verbose or not matcher.exact(old)
                 or not matcher.exact(new)):
                 repo.ui.status(_('recording removal of %s as rename to %s '
                                  '(%d%% similar)\n') %
                                (matcher.rel(old), matcher.rel(new),
                                 score * 100))
             renames[new] = old
     return renames
 
 def _markchanges(repo, unknown, deleted, renames):
     '''Marks the files in unknown as added, the files in deleted as removed,
     and the files in renames as copied.'''
     wctx = repo[None]
     with repo.wlock():
         wctx.forget(deleted)
         wctx.add(unknown)
         for new, old in renames.iteritems():
             wctx.copy(old, new)
 
 def dirstatecopy(ui, repo, wctx, src, dst, dryrun=False, cwd=None):
     """Update the dirstate to reflect the intent of copying src to dst. For
     different reasons it might not end with dst being marked as copied from src.
     """
     origsrc = repo.dirstate.copied(src) or src
     if dst == origsrc: # copying back a copy?
         if repo.dirstate[dst] not in 'mn' and not dryrun:
             repo.dirstate.normallookup(dst)
     else:
         if repo.dirstate[origsrc] == 'a' and origsrc == src:
             if not ui.quiet:
                 ui.warn(_("%s has not been committed yet, so no copy "
                           "data will be stored for %s.\n")
                         % (repo.pathto(origsrc, cwd), repo.pathto(dst, cwd)))
             if repo.dirstate[dst] in '?r' and not dryrun:
                 wctx.add([dst])
         elif not dryrun:
             wctx.copy(origsrc, dst)
 
 def readrequires(opener, supported):
     '''Reads and parses .hg/requires and checks if all entries found
     are in the list of supported features.'''
     requirements = set(opener.read("requires").splitlines())
     missings = []
     for r in requirements:
         if r not in supported:
             if not r or not r[0:1].isalnum():
                 raise error.RequirementError(_(".hg/requires file is corrupt"))
             missings.append(r)
     missings.sort()
     if missings:
         raise error.RequirementError(
             _("repository requires features unknown to this Mercurial: %s")
             % " ".join(missings),
             hint=_("see https://mercurial-scm.org/wiki/MissingRequirement"
                    " for more information"))
     return requirements
 
 def writerequires(opener, requirements):
     with opener('requires', 'w') as fp:
         for r in sorted(requirements):
             fp.write("%s\n" % r)
 
 class filecachesubentry(object):
     def __init__(self, path, stat):
         self.path = path
         self.cachestat = None
         self._cacheable = None
 
         if stat:
             self.cachestat = filecachesubentry.stat(self.path)
 
             if self.cachestat:
                 self._cacheable = self.cachestat.cacheable()
             else:
                 # None means we don't know yet
                 self._cacheable = None
 
     def refresh(self):
         if self.cacheable():
             self.cachestat = filecachesubentry.stat(self.path)
 
     def cacheable(self):
         if self._cacheable is not None:
             return self._cacheable
 
         # we don't know yet, assume it is for now
         return True
 
     def changed(self):
         # no point in going further if we can't cache it
         if not self.cacheable():
             return True
 
         newstat = filecachesubentry.stat(self.path)
 
         # we may not know if it's cacheable yet, check again now
         if newstat and self._cacheable is None:
             self._cacheable = newstat.cacheable()
 
             # check again
             if not self._cacheable:
                 return True
 
         if self.cachestat != newstat:
             self.cachestat = newstat
             return True
         else:
             return False
 
     @staticmethod
     def stat(path):
         try:
             return util.cachestat(path)
         except OSError as e:
             if e.errno != errno.ENOENT:
                 raise
 
 class filecacheentry(object):
     def __init__(self, paths, stat=True):
         self._entries = []
         for path in paths:
             self._entries.append(filecachesubentry(path, stat))
 
     def changed(self):
         '''true if any entry has changed'''
         for entry in self._entries:
             if entry.changed():
                 return True
         return False
 
     def refresh(self):
         for entry in self._entries:
             entry.refresh()
 
 class filecache(object):
     '''A property like decorator that tracks files under .hg/ for updates.
 
     Records stat info when called in _filecache.
 
     On subsequent calls, compares old stat info with new info, and recreates the
     object when any of the files changes, updating the new stat info in
     _filecache.
 
     Mercurial either atomic renames or appends for files under .hg,
     so to ensure the cache is reliable we need the filesystem to be able
     to tell us if a file has been replaced. If it can't, we fallback to
     recreating the object on every call (essentially the same behavior as
     propertycache).
 
     '''
     def __init__(self, *paths):
         self.paths = paths
 
     def join(self, obj, fname):
         """Used to compute the runtime path of a cached file.
 
         Users should subclass filecache and provide their own version of this
         function to call the appropriate join function on 'obj' (an instance
         of the class that its member function was decorated).
         """
         raise NotImplementedError
 
     def __call__(self, func):
         self.func = func
         self.sname = func.__name__
         self.name = pycompat.sysbytes(self.sname)
         return self
 
     def __get__(self, obj, type=None):
         # if accessed on the class, return the descriptor itself.
         if obj is None:
             return self
         # do we need to check if the file changed?
         if self.sname in obj.__dict__:
             assert self.name in obj._filecache, self.name
             return obj.__dict__[self.sname]
 
         entry = obj._filecache.get(self.name)
 
         if entry:
             if entry.changed():
                 entry.obj = self.func(obj)
         else:
             paths = [self.join(obj, path) for path in self.paths]
 
             # We stat -before- creating the object so our cache doesn't lie if
             # a writer modified between the time we read and stat
             entry = filecacheentry(paths, True)
             entry.obj = self.func(obj)
 
             obj._filecache[self.name] = entry
 
         obj.__dict__[self.sname] = entry.obj
         return entry.obj
 
     def __set__(self, obj, value):
         if self.name not in obj._filecache:
             # we add an entry for the missing value because X in __dict__
             # implies X in _filecache
             paths = [self.join(obj, path) for path in self.paths]
             ce = filecacheentry(paths, False)
             obj._filecache[self.name] = ce
         else:
             ce = obj._filecache[self.name]
 
         ce.obj = value # update cached copy
         obj.__dict__[self.sname] = value # update copy returned by obj.x
 
     def __delete__(self, obj):
         try:
             del obj.__dict__[self.sname]
         except KeyError:
             raise AttributeError(self.sname)
 
 def extdatasource(repo, source):
     """Gather a map of rev -> value dict from the specified source
 
     A source spec is treated as a URL, with a special case shell: type
     for parsing the output from a shell command.
 
     The data is parsed as a series of newline-separated records where
     each record is a revision specifier optionally followed by a space
     and a freeform string value. If the revision is known locally, it
     is converted to a rev, otherwise the record is skipped.
 
     Note that both key and value are treated as UTF-8 and converted to
     the local encoding. This allows uniformity between local and
     remote data sources.
     """
 
     spec = repo.ui.config("extdata", source)
     if not spec:
         raise error.Abort(_("unknown extdata source '%s'") % source)
 
     data = {}
     src = proc = None
     try:
         if spec.startswith("shell:"):
             # external commands should be run relative to the repo root
             cmd = spec[6:]
             proc = subprocess.Popen(cmd, shell=True, bufsize=-1,
                                     close_fds=procutil.closefds,
                                     stdout=subprocess.PIPE, cwd=repo.root)
             src = proc.stdout
         else:
             # treat as a URL or file
             src = url.open(repo.ui, spec)
         for l in src:
             if " " in l:
                 k, v = l.strip().split(" ", 1)
             else:
                 k, v = l.strip(), ""
 
             k = encoding.tolocal(k)
             try:
                 data[revsingle(repo, k).rev()] = encoding.tolocal(v)
             except (error.LookupError, error.RepoLookupError):
                 pass # we ignore data for nodes that don't exist locally
     finally:
         if proc:
             proc.communicate()
         if src:
             src.close()
     if proc and proc.returncode != 0:
         raise error.Abort(_("extdata command '%s' failed: %s")
                           % (cmd, procutil.explainexit(proc.returncode)))
 
     return data
 
 def _locksub(repo, lock, envvar, cmd, environ=None, *args, **kwargs):
     if lock is None:
         raise error.LockInheritanceContractViolation(
             'lock can only be inherited while held')
     if environ is None:
         environ = {}
     with lock.inherit() as locker:
         environ[envvar] = locker
         return repo.ui.system(cmd, environ=environ, *args, **kwargs)
 
 def wlocksub(repo, cmd, *args, **kwargs):
     """run cmd as a subprocess that allows inheriting repo's wlock
 
     This can only be called while the wlock is held. This takes all the
     arguments that ui.system does, and returns the exit code of the
     subprocess."""
     return _locksub(repo, repo.currentwlock(), 'HG_WLOCK_LOCKER', cmd, *args,
                     **kwargs)
 
+class progress(object):
+    def __init__(self, ui, topic, unit="", total=None):
+        self.ui = ui
+        self.pos = 0
+        self.topic = topic
+        self.unit = unit
+        self.total = total
+
+    def update(self, pos, item="", total=None):
+        if total:
+            self.total = total
+        self.pos = pos
+        self._print(item)
+
+    def increment(self, step=1, item="", total=None):
+        self.update(self.pos + step, item, total)
+
+    def _print(self, item):
+        self.ui.progress(self.topic, self.pos, item, self.unit,
+                         self.total)
+
 def gdinitconfig(ui):
     """helper function to know if a repo should be created as general delta
     """
     # experimental config: format.generaldelta
     return (ui.configbool('format', 'generaldelta')
             or ui.configbool('format', 'usegeneraldelta'))
 
 def gddeltaconfig(ui):
     """helper function to know if incoming delta should be optimised
     """
     # experimental config: format.generaldelta
     return ui.configbool('format', 'generaldelta')
 
 class simplekeyvaluefile(object):
     """A simple file with key=value lines
 
     Keys must be alphanumerics and start with a letter, values must not
     contain '\n' characters"""
     firstlinekey = '__firstline'
 
     def __init__(self, vfs, path, keys=None):
         self.vfs = vfs
         self.path = path
 
     def read(self, firstlinenonkeyval=False):
         """Read the contents of a simple key-value file
 
         'firstlinenonkeyval' indicates whether the first line of file should
         be treated as a key-value pair or reuturned fully under the
         __firstline key."""
         lines = self.vfs.readlines(self.path)
         d = {}
         if firstlinenonkeyval:
             if not lines:
                 e = _("empty simplekeyvalue file")
                 raise error.CorruptedState(e)
             # we don't want to include '\n' in the __firstline
             d[self.firstlinekey] = lines[0][:-1]
             del lines[0]
 
         try:
             # the 'if line.strip()' part prevents us from failing on empty
             # lines which only contain '\n' therefore are not skipped
             # by 'if line'
             updatedict = dict(line[:-1].split('=', 1) for line in lines
                                                       if line.strip())
             if self.firstlinekey in updatedict:
                 e = _("%r can't be used as a key")
                 raise error.CorruptedState(e % self.firstlinekey)
             d.update(updatedict)
         except ValueError as e:
             raise error.CorruptedState(str(e))
         return d
 
     def write(self, data, firstline=None):
         """Write key=>value mapping to a file
         data is a dict. Keys must be alphanumerical and start with a letter.
         Values must not contain newline characters.
 
         If 'firstline' is not None, it is written to file before
         everything else, as it is, not in a key=value form"""
         lines = []
         if firstline is not None:
             lines.append('%s\n' % firstline)
 
         for k, v in data.items():
             if k == self.firstlinekey:
                 e = "key name '%s' is reserved" % self.firstlinekey
                 raise error.ProgrammingError(e)
             if not k[0:1].isalpha():
                 e = "keys must start with a letter in a key-value file"
                 raise error.ProgrammingError(e)
             if not k.isalnum():
                 e = "invalid key name in a simple key-value file"
                 raise error.ProgrammingError(e)
             if '\n' in v:
                 e = "invalid value in a simple key-value file"
                 raise error.ProgrammingError(e)
             lines.append("%s=%s\n" % (k, v))
         with self.vfs(self.path, mode='wb', atomictemp=True) as fp:
             fp.write(''.join(lines))
 
 _reportobsoletedsource = [
     'debugobsolete',
     'pull',
     'push',
     'serve',
     'unbundle',
 ]
 
 _reportnewcssource = [
     'pull',
     'unbundle',
 ]
 
 def prefetchfiles(repo, revs, match):
     """Invokes the registered file prefetch functions, allowing extensions to
     ensure the corresponding files are available locally, before the command
     uses them."""
     if match:
         # The command itself will complain about files that don't exist, so
         # don't duplicate the message.
         match = matchmod.badmatch(match, lambda fn, msg: None)
     else:
         match = matchall(repo)
 
     fileprefetchhooks(repo, revs, match)
 
 # a list of (repo, revs, match) prefetch functions
 fileprefetchhooks = util.hooks()
 
 # A marker that tells the evolve extension to suppress its own reporting
 _reportstroubledchangesets = True
 
 def registersummarycallback(repo, otr, txnname=''):
     """register a callback to issue a summary after the transaction is closed
     """
     def txmatch(sources):
         return any(txnname.startswith(source) for source in sources)
 
     categories = []
 
     def reportsummary(func):
         """decorator for report callbacks."""
         # The repoview life cycle is shorter than the one of the actual
         # underlying repository. So the filtered object can die before the
         # weakref is used leading to troubles. We keep a reference to the
         # unfiltered object and restore the filtering when retrieving the
         # repository through the weakref.
         filtername = repo.filtername
         reporef = weakref.ref(repo.unfiltered())
         def wrapped(tr):
             repo = reporef()
             if filtername:
                 repo = repo.filtered(filtername)
             func(repo, tr)
         newcat = '%02i-txnreport' % len(categories)
         otr.addpostclose(newcat, wrapped)
         categories.append(newcat)
         return wrapped
 
     if txmatch(_reportobsoletedsource):
         @reportsummary
         def reportobsoleted(repo, tr):
             obsoleted = obsutil.getobsoleted(repo, tr)
             if obsoleted:
                 repo.ui.status(_('obsoleted %i changesets\n')
                                % len(obsoleted))
 
     if (obsolete.isenabled(repo, obsolete.createmarkersopt) and
         repo.ui.configbool('experimental', 'evolution.report-instabilities')):
         instabilitytypes = [
             ('orphan', 'orphan'),
             ('phase-divergent', 'phasedivergent'),
             ('content-divergent', 'contentdivergent'),
         ]
 
         def getinstabilitycounts(repo):
             filtered = repo.changelog.filteredrevs
             counts = {}
             for instability, revset in instabilitytypes:
                 counts[instability] = len(set(obsolete.getrevs(repo, revset)) -
                                           filtered)
             return counts
 
         oldinstabilitycounts = getinstabilitycounts(repo)
         @reportsummary
         def reportnewinstabilities(repo, tr):
             newinstabilitycounts = getinstabilitycounts(repo)
             for instability, revset in instabilitytypes:
                 delta = (newinstabilitycounts[instability] -
                          oldinstabilitycounts[instability])
                 if delta > 0:
                     repo.ui.warn(_('%i new %s changesets\n') %
                                  (delta, instability))
 
     if txmatch(_reportnewcssource):
         @reportsummary
         def reportnewcs(repo, tr):
             """Report the range of new revisions pulled/unbundled."""
             newrevs = tr.changes.get('revs', xrange(0, 0))
             if not newrevs:
                 return
 
             # Compute the bounds of new revisions' range, excluding obsoletes.
             unfi = repo.unfiltered()
             revs = unfi.revs('%ld and not obsolete()', newrevs)
             if not revs:
                 # Got only obsoletes.
                 return
             minrev, maxrev = repo[revs.min()], repo[revs.max()]
 
             if minrev == maxrev:
                 revrange = minrev
             else:
                 revrange = '%s:%s' % (minrev, maxrev)
             repo.ui.status(_('new changesets %s\n') % revrange)
 
         @reportsummary
         def reportphasechanges(repo, tr):
             """Report statistics of phase changes for changesets pre-existing
             pull/unbundle.
             """
             newrevs = tr.changes.get('revs', xrange(0, 0))
             phasetracking = tr.changes.get('phases', {})
             if not phasetracking:
                 return
             published = [
                 rev for rev, (old, new) in phasetracking.iteritems()
                 if new == phases.public and rev not in newrevs
             ]
             if not published:
                 return
             repo.ui.status(_('%d local changesets published\n')
                            % len(published))
 
 def nodesummaries(repo, nodes, maxnumnodes=4):
     if len(nodes) <= maxnumnodes or repo.ui.verbose:
         return ' '.join(short(h) for h in nodes)
     first = ' '.join(short(h) for h in nodes[:maxnumnodes])
     return _("%s and %d others") % (first, len(nodes) - maxnumnodes)
 
 def enforcesinglehead(repo, tr, desc):
     """check that no named branch has multiple heads"""
     if desc in ('strip', 'repair'):
         # skip the logic during strip
         return
     visible = repo.filtered('visible')
     # possible improvement: we could restrict the check to affected branch
     for name, heads in visible.branchmap().iteritems():
         if len(heads) > 1:
             msg = _('rejecting multiple heads on branch "%s"')
             msg %= name
             hint = _('%d heads: %s')
             hint %= (len(heads), nodesummaries(repo, heads))
             raise error.Abort(msg, hint=hint)
 
 def wrapconvertsink(sink):
     """Allow extensions to wrap the sink returned by convcmd.convertsink()
     before it is used, whether or not the convert extension was formally loaded.
     """
     return sink
 
 def unhidehashlikerevs(repo, specs, hiddentype):
     """parse the user specs and unhide changesets whose hash or revision number
     is passed.
 
     hiddentype can be: 1) 'warn': warn while unhiding changesets
                        2) 'nowarn': don't warn while unhiding changesets
 
     returns a repo object with the required changesets unhidden
     """
     if not repo.filtername or not repo.ui.configbool('experimental',
                                                      'directaccess'):
         return repo
 
     if repo.filtername not in ('visible', 'visible-hidden'):
         return repo
 
     symbols = set()
     for spec in specs:
         try:
             tree = revsetlang.parse(spec)
         except error.ParseError: # will be reported by scmutil.revrange()
             continue
 
         symbols.update(revsetlang.gethashlikesymbols(tree))
 
     if not symbols:
         return repo
 
     revs = _getrevsfromsymbols(repo, symbols)
 
     if not revs:
         return repo
 
     if hiddentype == 'warn':
         unfi = repo.unfiltered()
         revstr = ", ".join([pycompat.bytestr(unfi[l]) for l in revs])
         repo.ui.warn(_("warning: accessing hidden changesets for write "
                        "operation: %s\n") % revstr)
 
     # we have to use new filtername to separate branch/tags cache until we can
     # disbale these cache when revisions are dynamically pinned.
     return repo.filtered('visible-hidden', revs)
 
 def _getrevsfromsymbols(repo, symbols):
     """parse the list of symbols and returns a set of revision numbers of hidden
     changesets present in symbols"""
     revs = set()
     unfi = repo.unfiltered()
     unficl = unfi.changelog
     cl = repo.changelog
     tiprev = len(unficl)
     allowrevnums = repo.ui.configbool('experimental', 'directaccess.revnums')
     for s in symbols:
         try:
             n = int(s)
             if n <= tiprev:
                 if not allowrevnums:
                     continue
                 else:
                     if n not in cl:
                         revs.add(n)
                     continue
         except ValueError:
             pass
 
         try:
             s = resolvehexnodeidprefix(unfi, s)
         except (error.LookupError, error.WdirUnsupported):
             s = None
 
         if s is not None:
             rev = unficl.rev(s)
             if rev not in cl:
                 revs.add(rev)
 
     return revs
 
 def bookmarkrevs(repo, mark):
     """
     Select revisions reachable by a given bookmark
     """
     return repo.revs("ancestors(bookmark(%s)) - "
                      "ancestors(head() and not bookmark(%s)) - "
                      "ancestors(bookmark() and not bookmark(%s))",
                      mark, mark, mark)

mercurial/ui.py

@@ -1,1869 +1,1873 b''
 # ui.py - user interface bits for mercurial
 #
 # Copyright 2005-2007 Matt 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.
 
 from __future__ import absolute_import
 
 import collections
 import contextlib
 import errno
 import getpass
 import inspect
 import os
 import re
 import signal
 import socket
 import subprocess
 import sys
 import traceback
 
 from .i18n import _
 from .node import hex
 
 from . import (
     color,
     config,
     configitems,
     encoding,
     error,
     formatter,
     progress,
     pycompat,
     rcutil,
     scmutil,
     util,
 )
 from .utils import (
     dateutil,
     procutil,
     stringutil,
 )
 
 urlreq = util.urlreq
 
 # for use with str.translate(None, _keepalnum), to keep just alphanumerics
 _keepalnum = ''.join(c for c in map(pycompat.bytechr, range(256))
                      if not c.isalnum())
 
 # The config knobs that will be altered (if unset) by ui.tweakdefaults.
 tweakrc = b"""
 [ui]
 # The rollback command is dangerous. As a rule, don't use it.
 rollback = False
 # Make `hg status` report copy information
 statuscopies = yes
 # Prefer curses UIs when available. Revert to plain-text with `text`.
 interface = curses
 
 [commands]
 # Make `hg status` emit cwd-relative paths by default.
 status.relative = yes
 # Refuse to perform an `hg update` that would cause a file content merge
 update.check = noconflict
 # Show conflicts information in `hg status`
 status.verbose = True
 # Collapse entire directories that contain only unknown files
 status.terse = u
 
 [diff]
 git = 1
 showfunc = 1
 """
 
 samplehgrcs = {
     'user':
 b"""# example user config (see 'hg help config' for more info)
 [ui]
 # name and email, e.g.
 # username = Jane Doe <[e-mail]>
 username =
 
 # We recommend enabling tweakdefaults to get slight improvements to
 # the UI over time. Make sure to set HGPLAIN in the environment when
 # writing scripts!
 # tweakdefaults = True
 
 # uncomment to disable color in command output
 # (see 'hg help color' for details)
 # color = never
 
 # uncomment to disable command output pagination
 # (see 'hg help pager' for details)
 # paginate = never
 
 [extensions]
 # uncomment these lines to enable some popular extensions
 # (see 'hg help extensions' for more info)
 #
 # churn =
 """,
 
     'cloned':
 b"""# example repository config (see 'hg help config' for more info)
 [paths]
 default = %s
 
 # path aliases to other clones of this repo in URLs or filesystem paths
 # (see 'hg help config.paths' for more info)
 #
 # default:pushurl = ssh://[e-mail]/hg/jdoes-fork
 # my-fork         = ssh://[e-mail]/hg/jdoes-fork
 # my-clone        = /home/jdoe/jdoes-clone
 
 [ui]
 # name and email (local to this repository, optional), e.g.
 # username = Jane Doe <[e-mail]>
 """,
 
     'local':
 b"""# example repository config (see 'hg help config' for more info)
 [paths]
 # path aliases to other clones of this repo in URLs or filesystem paths
 # (see 'hg help config.paths' for more info)
 #
 # default         = http://example.com/hg/example-repo
 # default:pushurl = ssh://[e-mail]/hg/jdoes-fork
 # my-fork         = ssh://[e-mail]/hg/jdoes-fork
 # my-clone        = /home/jdoe/jdoes-clone
 
 [ui]
 # name and email (local to this repository, optional), e.g.
 # username = Jane Doe <[e-mail]>
 """,
 
     'global':
 b"""# example system-wide hg config (see 'hg help config' for more info)
 
 [ui]
 # uncomment to disable color in command output
 # (see 'hg help color' for details)
 # color = never
 
 # uncomment to disable command output pagination
 # (see 'hg help pager' for details)
 # paginate = never
 
 [extensions]
 # uncomment these lines to enable some popular extensions
 # (see 'hg help extensions' for more info)
 #
 # blackbox =
 # churn =
 """,
 }
 
 def _maybestrurl(maybebytes):
     return util.rapply(pycompat.strurl, maybebytes)
 
 def _maybebytesurl(maybestr):
     return util.rapply(pycompat.bytesurl, maybestr)
 
 class httppasswordmgrdbproxy(object):
     """Delays loading urllib2 until it's needed."""
     def __init__(self):
         self._mgr = None
 
     def _get_mgr(self):
         if self._mgr is None:
             self._mgr = urlreq.httppasswordmgrwithdefaultrealm()
         return self._mgr
 
     def add_password(self, realm, uris, user, passwd):
         return self._get_mgr().add_password(
             _maybestrurl(realm), _maybestrurl(uris),
             _maybestrurl(user), _maybestrurl(passwd))
 
     def find_user_password(self, realm, uri):
         mgr = self._get_mgr()
         return _maybebytesurl(mgr.find_user_password(_maybestrurl(realm),
                                                      _maybestrurl(uri)))
 
 def _catchterm(*args):
     raise error.SignalInterrupt
 
 # unique object used to detect no default value has been provided when
 # retrieving configuration value.
 _unset = object()
 
 # _reqexithandlers: callbacks run at the end of a request
 _reqexithandlers = []
 
 class ui(object):
     def __init__(self, src=None):
         """Create a fresh new ui object if no src given
 
         Use uimod.ui.load() to create a ui which knows global and user configs.
         In most cases, you should use ui.copy() to create a copy of an existing
         ui object.
         """
         # _buffers: used for temporary capture of output
         self._buffers = []
         # 3-tuple describing how each buffer in the stack behaves.
         # Values are (capture stderr, capture subprocesses, apply labels).
         self._bufferstates = []
         # When a buffer is active, defines whether we are expanding labels.
         # This exists to prevent an extra list lookup.
         self._bufferapplylabels = None
         self.quiet = self.verbose = self.debugflag = self.tracebackflag = False
         self._reportuntrusted = True
         self._knownconfig = configitems.coreitems
         self._ocfg = config.config() # overlay
         self._tcfg = config.config() # trusted
         self._ucfg = config.config() # untrusted
         self._trustusers = set()
         self._trustgroups = set()
         self.callhooks = True
         # Insecure server connections requested.
         self.insecureconnections = False
         # Blocked time
         self.logblockedtimes = False
         # color mode: see mercurial/color.py for possible value
         self._colormode = None
         self._terminfoparams = {}
         self._styles = {}
 
         if src:
             self.fout = src.fout
             self.ferr = src.ferr
             self.fin = src.fin
             self.pageractive = src.pageractive
             self._disablepager = src._disablepager
             self._tweaked = src._tweaked
 
             self._tcfg = src._tcfg.copy()
             self._ucfg = src._ucfg.copy()
             self._ocfg = src._ocfg.copy()
             self._trustusers = src._trustusers.copy()
             self._trustgroups = src._trustgroups.copy()
             self.environ = src.environ
             self.callhooks = src.callhooks
             self.insecureconnections = src.insecureconnections
             self._colormode = src._colormode
             self._terminfoparams = src._terminfoparams.copy()
             self._styles = src._styles.copy()
 
             self.fixconfig()
 
             self.httppasswordmgrdb = src.httppasswordmgrdb
             self._blockedtimes = src._blockedtimes
         else:
             self.fout = procutil.stdout
             self.ferr = procutil.stderr
             self.fin = procutil.stdin
             self.pageractive = False
             self._disablepager = False
             self._tweaked = False
 
             # shared read-only environment
             self.environ = encoding.environ
 
             self.httppasswordmgrdb = httppasswordmgrdbproxy()
             self._blockedtimes = collections.defaultdict(int)
 
         allowed = self.configlist('experimental', 'exportableenviron')
         if '*' in allowed:
             self._exportableenviron = self.environ
         else:
             self._exportableenviron = {}
             for k in allowed:
                 if k in self.environ:
                     self._exportableenviron[k] = self.environ[k]
 
     @classmethod
     def load(cls):
         """Create a ui and load global and user configs"""
         u = cls()
         # we always trust global config files and environment variables
         for t, f in rcutil.rccomponents():
             if t == 'path':
                 u.readconfig(f, trust=True)
             elif t == 'items':
                 sections = set()
                 for section, name, value, source in f:
                     # do not set u._ocfg
                     # XXX clean this up once immutable config object is a thing
                     u._tcfg.set(section, name, value, source)
                     u._ucfg.set(section, name, value, source)
                     sections.add(section)
                 for section in sections:
                     u.fixconfig(section=section)
             else:
                 raise error.ProgrammingError('unknown rctype: %s' % t)
         u._maybetweakdefaults()
         return u
 
     def _maybetweakdefaults(self):
         if not self.configbool('ui', 'tweakdefaults'):
             return
         if self._tweaked or self.plain('tweakdefaults'):
             return
 
         # Note: it is SUPER IMPORTANT that you set self._tweaked to
         # True *before* any calls to setconfig(), otherwise you'll get
         # infinite recursion between setconfig and this method.
         #
         # TODO: We should extract an inner method in setconfig() to
         # avoid this weirdness.
         self._tweaked = True
         tmpcfg = config.config()
         tmpcfg.parse('<tweakdefaults>', tweakrc)
         for section in tmpcfg:
             for name, value in tmpcfg.items(section):
                 if not self.hasconfig(section, name):
                     self.setconfig(section, name, value, "<tweakdefaults>")
 
     def copy(self):
         return self.__class__(self)
 
     def resetstate(self):
         """Clear internal state that shouldn't persist across commands"""
         if self._progbar:
             self._progbar.resetstate()  # reset last-print time of progress bar
         self.httppasswordmgrdb = httppasswordmgrdbproxy()
 
     @contextlib.contextmanager
     def timeblockedsection(self, key):
         # this is open-coded below - search for timeblockedsection to find them
         starttime = util.timer()
         try:
             yield
         finally:
             self._blockedtimes[key + '_blocked'] += \
                 (util.timer() - starttime) * 1000
 
     def formatter(self, topic, opts):
         return formatter.formatter(self, self, topic, opts)
 
     def _trusted(self, fp, f):
         st = util.fstat(fp)
         if util.isowner(st):
             return True
 
         tusers, tgroups = self._trustusers, self._trustgroups
         if '*' in tusers or '*' in tgroups:
             return True
 
         user = util.username(st.st_uid)
         group = util.groupname(st.st_gid)
         if user in tusers or group in tgroups or user == util.username():
             return True
 
         if self._reportuntrusted:
             self.warn(_('not trusting file %s from untrusted '
                         'user %s, group %s\n') % (f, user, group))
         return False
 
     def readconfig(self, filename, root=None, trust=False,
                    sections=None, remap=None):
         try:
             fp = open(filename, u'rb')
         except IOError:
             if not sections: # ignore unless we were looking for something
                 return
             raise
 
         cfg = config.config()
         trusted = sections or trust or self._trusted(fp, filename)
 
         try:
             cfg.read(filename, fp, sections=sections, remap=remap)
             fp.close()
         except error.ConfigError as inst:
             if trusted:
                 raise
             self.warn(_("ignored: %s\n") % stringutil.forcebytestr(inst))
 
         if self.plain():
             for k in ('debug', 'fallbackencoding', 'quiet', 'slash',
                       'logtemplate', 'statuscopies', 'style',
                       'traceback', 'verbose'):
                 if k in cfg['ui']:
                     del cfg['ui'][k]
             for k, v in cfg.items('defaults'):
                 del cfg['defaults'][k]
             for k, v in cfg.items('commands'):
                 del cfg['commands'][k]
         # Don't remove aliases from the configuration if in the exceptionlist
         if self.plain('alias'):
             for k, v in cfg.items('alias'):
                 del cfg['alias'][k]
         if self.plain('revsetalias'):
             for k, v in cfg.items('revsetalias'):
                 del cfg['revsetalias'][k]
         if self.plain('templatealias'):
             for k, v in cfg.items('templatealias'):
                 del cfg['templatealias'][k]
 
         if trusted:
             self._tcfg.update(cfg)
             self._tcfg.update(self._ocfg)
         self._ucfg.update(cfg)
         self._ucfg.update(self._ocfg)
 
         if root is None:
             root = os.path.expanduser('~')
         self.fixconfig(root=root)
 
     def fixconfig(self, root=None, section=None):
         if section in (None, 'paths'):
             # expand vars and ~
             # translate paths relative to root (or home) into absolute paths
             root = root or pycompat.getcwd()
             for c in self._tcfg, self._ucfg, self._ocfg:
                 for n, p in c.items('paths'):
                     # Ignore sub-options.
                     if ':' in n:
                         continue
                     if not p:
                         continue
                     if '%%' in p:
                         s = self.configsource('paths', n) or 'none'
                         self.warn(_("(deprecated '%%' in path %s=%s from %s)\n")
                                   % (n, p, s))
                         p = p.replace('%%', '%')
                     p = util.expandpath(p)
                     if not util.hasscheme(p) and not os.path.isabs(p):
                         p = os.path.normpath(os.path.join(root, p))
                     c.set("paths", n, p)
 
         if section in (None, 'ui'):
             # update ui options
             self.debugflag = self.configbool('ui', 'debug')
             self.verbose = self.debugflag or self.configbool('ui', 'verbose')
             self.quiet = not self.debugflag and self.configbool('ui', 'quiet')
             if self.verbose and self.quiet:
                 self.quiet = self.verbose = False
             self._reportuntrusted = self.debugflag or self.configbool("ui",
                 "report_untrusted")
             self.tracebackflag = self.configbool('ui', 'traceback')
             self.logblockedtimes = self.configbool('ui', 'logblockedtimes')
 
         if section in (None, 'trusted'):
             # update trust information
             self._trustusers.update(self.configlist('trusted', 'users'))
             self._trustgroups.update(self.configlist('trusted', 'groups'))
 
     def backupconfig(self, section, item):
         return (self._ocfg.backup(section, item),
                 self._tcfg.backup(section, item),
                 self._ucfg.backup(section, item),)
     def restoreconfig(self, data):
         self._ocfg.restore(data[0])
         self._tcfg.restore(data[1])
         self._ucfg.restore(data[2])
 
     def setconfig(self, section, name, value, source=''):
         for cfg in (self._ocfg, self._tcfg, self._ucfg):
             cfg.set(section, name, value, source)
         self.fixconfig(section=section)
         self._maybetweakdefaults()
 
     def _data(self, untrusted):
         return untrusted and self._ucfg or self._tcfg
 
     def configsource(self, section, name, untrusted=False):
         return self._data(untrusted).source(section, name)
 
     def config(self, section, name, default=_unset, untrusted=False):
         """return the plain string version of a config"""
         value = self._config(section, name, default=default,
                              untrusted=untrusted)
         if value is _unset:
             return None
         return value
 
     def _config(self, section, name, default=_unset, untrusted=False):
         value = itemdefault = default
         item = self._knownconfig.get(section, {}).get(name)
         alternates = [(section, name)]
 
         if item is not None:
             alternates.extend(item.alias)
             if callable(item.default):
                 itemdefault = item.default()
             else:
                 itemdefault = item.default
         else:
             msg = ("accessing unregistered config item: '%s.%s'")
             msg %= (section, name)
             self.develwarn(msg, 2, 'warn-config-unknown')
 
         if default is _unset:
             if item is None:
                 value = default
             elif item.default is configitems.dynamicdefault:
                 value = None
                 msg = "config item requires an explicit default value: '%s.%s'"
                 msg %= (section, name)
                 self.develwarn(msg, 2, 'warn-config-default')
             else:
                 value = itemdefault
         elif (item is not None
               and item.default is not configitems.dynamicdefault
               and default != itemdefault):
             msg = ("specifying a mismatched default value for a registered "
                    "config item: '%s.%s' '%s'")
             msg %= (section, name, pycompat.bytestr(default))
             self.develwarn(msg, 2, 'warn-config-default')
 
         for s, n in alternates:
             candidate = self._data(untrusted).get(s, n, None)
             if candidate is not None:
                 value = candidate
                 section = s
                 name = n
                 break
 
         if self.debugflag and not untrusted and self._reportuntrusted:
             for s, n in alternates:
                 uvalue = self._ucfg.get(s, n)
                 if uvalue is not None and uvalue != value:
                     self.debug("ignoring untrusted configuration option "
                                "%s.%s = %s\n" % (s, n, uvalue))
         return value
 
     def configsuboptions(self, section, name, default=_unset, untrusted=False):
         """Get a config option and all sub-options.
 
         Some config options have sub-options that are declared with the
         format "key:opt = value". This method is used to return the main
         option and all its declared sub-options.
 
         Returns a 2-tuple of ``(option, sub-options)``, where `sub-options``
         is a dict of defined sub-options where keys and values are strings.
         """
         main = self.config(section, name, default, untrusted=untrusted)
         data = self._data(untrusted)
         sub = {}
         prefix = '%s:' % name
         for k, v in data.items(section):
             if k.startswith(prefix):
                 sub[k[len(prefix):]] = v
 
         if self.debugflag and not untrusted and self._reportuntrusted:
             for k, v in sub.items():
                 uvalue = self._ucfg.get(section, '%s:%s' % (name, k))
                 if uvalue is not None and uvalue != v:
                     self.debug('ignoring untrusted configuration option '
                                '%s:%s.%s = %s\n' % (section, name, k, uvalue))
 
         return main, sub
 
     def configpath(self, section, name, default=_unset, untrusted=False):
         'get a path config item, expanded relative to repo root or config file'
         v = self.config(section, name, default, untrusted)
         if v is None:
             return None
         if not os.path.isabs(v) or "://" not in v:
             src = self.configsource(section, name, untrusted)
             if ':' in src:
                 base = os.path.dirname(src.rsplit(':')[0])
                 v = os.path.join(base, os.path.expanduser(v))
         return v
 
     def configbool(self, section, name, default=_unset, untrusted=False):
         """parse a configuration element as a boolean
 
         >>> u = ui(); s = b'foo'
         >>> u.setconfig(s, b'true', b'yes')
         >>> u.configbool(s, b'true')
         True
         >>> u.setconfig(s, b'false', b'no')
         >>> u.configbool(s, b'false')
         False
         >>> u.configbool(s, b'unknown')
         False
         >>> u.configbool(s, b'unknown', True)
         True
         >>> u.setconfig(s, b'invalid', b'somevalue')
         >>> u.configbool(s, b'invalid')
         Traceback (most recent call last):
             ...
         ConfigError: foo.invalid is not a boolean ('somevalue')
         """
 
         v = self._config(section, name, default, untrusted=untrusted)
         if v is None:
             return v
         if v is _unset:
             if default is _unset:
                 return False
             return default
         if isinstance(v, bool):
             return v
         b = stringutil.parsebool(v)
         if b is None:
             raise error.ConfigError(_("%s.%s is not a boolean ('%s')")
                                     % (section, name, v))
         return b
 
     def configwith(self, convert, section, name, default=_unset,
                    desc=None, untrusted=False):
         """parse a configuration element with a conversion function
 
         >>> u = ui(); s = b'foo'
         >>> u.setconfig(s, b'float1', b'42')
         >>> u.configwith(float, s, b'float1')
         42.0
         >>> u.setconfig(s, b'float2', b'-4.25')
         >>> u.configwith(float, s, b'float2')
         -4.25
         >>> u.configwith(float, s, b'unknown', 7)
         7.0
         >>> u.setconfig(s, b'invalid', b'somevalue')
         >>> u.configwith(float, s, b'invalid')
         Traceback (most recent call last):
             ...
         ConfigError: foo.invalid is not a valid float ('somevalue')
         >>> u.configwith(float, s, b'invalid', desc=b'womble')
         Traceback (most recent call last):
             ...
         ConfigError: foo.invalid is not a valid womble ('somevalue')
         """
 
         v = self.config(section, name, default, untrusted)
         if v is None:
             return v # do not attempt to convert None
         try:
             return convert(v)
         except (ValueError, error.ParseError):
             if desc is None:
                 desc = pycompat.sysbytes(convert.__name__)
             raise error.ConfigError(_("%s.%s is not a valid %s ('%s')")
                                     % (section, name, desc, v))
 
     def configint(self, section, name, default=_unset, untrusted=False):
         """parse a configuration element as an integer
 
         >>> u = ui(); s = b'foo'
         >>> u.setconfig(s, b'int1', b'42')
         >>> u.configint(s, b'int1')
         42
         >>> u.setconfig(s, b'int2', b'-42')
         >>> u.configint(s, b'int2')
         -42
         >>> u.configint(s, b'unknown', 7)
         7
         >>> u.setconfig(s, b'invalid', b'somevalue')
         >>> u.configint(s, b'invalid')
         Traceback (most recent call last):
             ...
         ConfigError: foo.invalid is not a valid integer ('somevalue')
         """
 
         return self.configwith(int, section, name, default, 'integer',
                                untrusted)
 
     def configbytes(self, section, name, default=_unset, untrusted=False):
         """parse a configuration element as a quantity in bytes
 
         Units can be specified as b (bytes), k or kb (kilobytes), m or
         mb (megabytes), g or gb (gigabytes).
 
         >>> u = ui(); s = b'foo'
         >>> u.setconfig(s, b'val1', b'42')
         >>> u.configbytes(s, b'val1')
         42
         >>> u.setconfig(s, b'val2', b'42.5 kb')
         >>> u.configbytes(s, b'val2')
         43520
         >>> u.configbytes(s, b'unknown', b'7 MB')
         7340032
         >>> u.setconfig(s, b'invalid', b'somevalue')
         >>> u.configbytes(s, b'invalid')
         Traceback (most recent call last):
             ...
         ConfigError: foo.invalid is not a byte quantity ('somevalue')
         """
 
         value = self._config(section, name, default, untrusted)
         if value is _unset:
             if default is _unset:
                 default = 0
             value = default
         if not isinstance(value, bytes):
             return value
         try:
             return util.sizetoint(value)
         except error.ParseError:
             raise error.ConfigError(_("%s.%s is not a byte quantity ('%s')")
                                     % (section, name, value))
 
     def configlist(self, section, name, default=_unset, untrusted=False):
         """parse a configuration element as a list of comma/space separated
         strings
 
         >>> u = ui(); s = b'foo'
         >>> u.setconfig(s, b'list1', b'this,is "a small" ,test')
         >>> u.configlist(s, b'list1')
         ['this', 'is', 'a small', 'test']
         >>> u.setconfig(s, b'list2', b'this, is "a small" , test ')
         >>> u.configlist(s, b'list2')
         ['this', 'is', 'a small', 'test']
         """
         # default is not always a list
         v = self.configwith(config.parselist, section, name, default,
                                'list', untrusted)
         if isinstance(v, bytes):
             return config.parselist(v)
         elif v is None:
             return []
         return v
 
     def configdate(self, section, name, default=_unset, untrusted=False):
         """parse a configuration element as a tuple of ints
 
         >>> u = ui(); s = b'foo'
         >>> u.setconfig(s, b'date', b'0 0')
         >>> u.configdate(s, b'date')
         (0, 0)
         """
         if self.config(section, name, default, untrusted):
             return self.configwith(dateutil.parsedate, section, name, default,
                                    'date', untrusted)
         if default is _unset:
             return None
         return default
 
     def hasconfig(self, section, name, untrusted=False):
         return self._data(untrusted).hasitem(section, name)
 
     def has_section(self, section, untrusted=False):
         '''tell whether section exists in config.'''
         return section in self._data(untrusted)
 
     def configitems(self, section, untrusted=False, ignoresub=False):
         items = self._data(untrusted).items(section)
         if ignoresub:
             items = [i for i in items if ':' not in i[0]]
         if self.debugflag and not untrusted and self._reportuntrusted:
             for k, v in self._ucfg.items(section):
                 if self._tcfg.get(section, k) != v:
                     self.debug("ignoring untrusted configuration option "
                                "%s.%s = %s\n" % (section, k, v))
         return items
 
     def walkconfig(self, untrusted=False):
         cfg = self._data(untrusted)
         for section in cfg.sections():
             for name, value in self.configitems(section, untrusted):
                 yield section, name, value
 
     def plain(self, feature=None):
         '''is plain mode active?
 
         Plain mode means that all configuration variables which affect
         the behavior and output of Mercurial should be
         ignored. Additionally, the output should be stable,
         reproducible and suitable for use in scripts or applications.
 
         The only way to trigger plain mode is by setting either the
         `HGPLAIN' or `HGPLAINEXCEPT' environment variables.
 
         The return value can either be
         - False if HGPLAIN is not set, or feature is in HGPLAINEXCEPT
         - False if feature is disabled by default and not included in HGPLAIN
         - True otherwise
         '''
         if ('HGPLAIN' not in encoding.environ and
                 'HGPLAINEXCEPT' not in encoding.environ):
             return False
         exceptions = encoding.environ.get('HGPLAINEXCEPT',
                 '').strip().split(',')
         # TODO: add support for HGPLAIN=+feature,-feature syntax
         if '+strictflags' not in encoding.environ.get('HGPLAIN', '').split(','):
             exceptions.append('strictflags')
         if feature and exceptions:
             return feature not in exceptions
         return True
 
     def username(self, acceptempty=False):
         """Return default username to be used in commits.
 
         Searched in this order: $HGUSER, [ui] section of hgrcs, $EMAIL
         and stop searching if one of these is set.
         If not found and acceptempty is True, returns None.
         If not found and ui.askusername is True, ask the user, else use
         ($LOGNAME or $USER or $LNAME or $USERNAME) + "@full.hostname".
         If no username could be found, raise an Abort error.
         """
         user = encoding.environ.get("HGUSER")
         if user is None:
             user = self.config("ui", "username")
             if user is not None:
                 user = os.path.expandvars(user)
         if user is None:
             user = encoding.environ.get("EMAIL")
         if user is None and acceptempty:
             return user
         if user is None and self.configbool("ui", "askusername"):
             user = self.prompt(_("enter a commit username:"), default=None)
         if user is None and not self.interactive():
             try:
                 user = '%s@%s' % (procutil.getuser(),
                                   encoding.strtolocal(socket.getfqdn()))
                 self.warn(_("no username found, using '%s' instead\n") % user)
             except KeyError:
                 pass
         if not user:
             raise error.Abort(_('no username supplied'),
                              hint=_("use 'hg config --edit' "
                                     'to set your username'))
         if "\n" in user:
             raise error.Abort(_("username %r contains a newline\n")
                               % pycompat.bytestr(user))
         return user
 
     def shortuser(self, user):
         """Return a short representation of a user name or email address."""
         if not self.verbose:
             user = stringutil.shortuser(user)
         return user
 
     def expandpath(self, loc, default=None):
         """Return repository location relative to cwd or from [paths]"""
         try:
             p = self.paths.getpath(loc)
             if p:
                 return p.rawloc
         except error.RepoError:
             pass
 
         if default:
             try:
                 p = self.paths.getpath(default)
                 if p:
                     return p.rawloc
             except error.RepoError:
                 pass
 
         return loc
 
     @util.propertycache
     def paths(self):
         return paths(self)
 
     def pushbuffer(self, error=False, subproc=False, labeled=False):
         """install a buffer to capture standard output of the ui object
 
         If error is True, the error output will be captured too.
 
         If subproc is True, output from subprocesses (typically hooks) will be
         captured too.
 
         If labeled is True, any labels associated with buffered
         output will be handled. By default, this has no effect
         on the output returned, but extensions and GUI tools may
         handle this argument and returned styled output. If output
         is being buffered so it can be captured and parsed or
         processed, labeled should not be set to True.
         """
         self._buffers.append([])
         self._bufferstates.append((error, subproc, labeled))
         self._bufferapplylabels = labeled
 
     def popbuffer(self):
         '''pop the last buffer and return the buffered output'''
         self._bufferstates.pop()
         if self._bufferstates:
             self._bufferapplylabels = self._bufferstates[-1][2]
         else:
             self._bufferapplylabels = None
 
         return "".join(self._buffers.pop())
 
     def canwritewithoutlabels(self):
         '''check if write skips the label'''
         if self._buffers and not self._bufferapplylabels:
             return True
         return self._colormode is None
 
     def canbatchlabeledwrites(self):
         '''check if write calls with labels are batchable'''
         # Windows color printing is special, see ``write``.
         return self._colormode != 'win32'
 
     def write(self, *args, **opts):
         '''write args to output
 
         By default, this method simply writes to the buffer or stdout.
         Color mode can be set on the UI class to have the output decorated
         with color modifier before being written to stdout.
 
         The color used is controlled by an optional keyword argument, "label".
         This should be a string containing label names separated by space.
         Label names take the form of "topic.type". For example, ui.debug()
         issues a label of "ui.debug".
 
         When labeling output for a specific command, a label of
         "cmdname.type" is recommended. For example, status issues
         a label of "status.modified" for modified files.
         '''
         if self._buffers:
             if self._bufferapplylabels:
                 label = opts.get(r'label', '')
                 self._buffers[-1].extend(self.label(a, label) for a in args)
             else:
                 self._buffers[-1].extend(args)
         else:
             self._writenobuf(*args, **opts)
 
     def _writenobuf(self, *args, **opts):
         if self._colormode == 'win32':
             # windows color printing is its own can of crab, defer to
             # the color module and that is it.
             color.win32print(self, self._write, *args, **opts)
         else:
             msgs = args
             if self._colormode is not None:
                 label = opts.get(r'label', '')
                 msgs = [self.label(a, label) for a in args]
             self._write(*msgs, **opts)
 
     def _write(self, *msgs, **opts):
         self._progclear()
         # opencode timeblockedsection because this is a critical path
         starttime = util.timer()
         try:
             self.fout.write(''.join(msgs))
         except IOError as err:
             raise error.StdioError(err)
         finally:
             self._blockedtimes['stdio_blocked'] += \
                 (util.timer() - starttime) * 1000
 
     def write_err(self, *args, **opts):
         self._progclear()
         if self._bufferstates and self._bufferstates[-1][0]:
             self.write(*args, **opts)
         elif self._colormode == 'win32':
             # windows color printing is its own can of crab, defer to
             # the color module and that is it.
             color.win32print(self, self._write_err, *args, **opts)
         else:
             msgs = args
             if self._colormode is not None:
                 label = opts.get(r'label', '')
                 msgs = [self.label(a, label) for a in args]
             self._write_err(*msgs, **opts)
 
     def _write_err(self, *msgs, **opts):
         try:
             with self.timeblockedsection('stdio'):
                 if not getattr(self.fout, 'closed', False):
                     self.fout.flush()
                 for a in msgs:
                     self.ferr.write(a)
                 # stderr may be buffered under win32 when redirected to files,
                 # including stdout.
                 if not getattr(self.ferr, 'closed', False):
                     self.ferr.flush()
         except IOError as inst:
             if inst.errno not in (errno.EPIPE, errno.EIO, errno.EBADF):
                 raise error.StdioError(inst)
 
     def flush(self):
         # opencode timeblockedsection because this is a critical path
         starttime = util.timer()
         try:
             try:
                 self.fout.flush()
             except IOError as err:
                 if err.errno not in (errno.EPIPE, errno.EIO, errno.EBADF):
                     raise error.StdioError(err)
             finally:
                 try:
                     self.ferr.flush()
                 except IOError as err:
                     if err.errno not in (errno.EPIPE, errno.EIO, errno.EBADF):
                         raise error.StdioError(err)
         finally:
             self._blockedtimes['stdio_blocked'] += \
                 (util.timer() - starttime) * 1000
 
     def _isatty(self, fh):
         if self.configbool('ui', 'nontty'):
             return False
         return procutil.isatty(fh)
 
     def disablepager(self):
         self._disablepager = True
 
     def pager(self, command):
         """Start a pager for subsequent command output.
 
         Commands which produce a long stream of output should call
         this function to activate the user's preferred pagination
         mechanism (which may be no pager). Calling this function
         precludes any future use of interactive functionality, such as
         prompting the user or activating curses.
 
         Args:
           command: The full, non-aliased name of the command. That is, "log"
                    not "history, "summary" not "summ", etc.
         """
         if (self._disablepager
             or self.pageractive):
             # how pager should do is already determined
             return
 
         if not command.startswith('internal-always-') and (
             # explicit --pager=on (= 'internal-always-' prefix) should
             # take precedence over disabling factors below
             command in self.configlist('pager', 'ignore')
             or not self.configbool('ui', 'paginate')
             or not self.configbool('pager', 'attend-' + command, True)
             # TODO: if we want to allow HGPLAINEXCEPT=pager,
             # formatted() will need some adjustment.
             or not self.formatted()
             or self.plain()
             or self._buffers
             # TODO: expose debugger-enabled on the UI object
             or '--debugger' in pycompat.sysargv):
             # We only want to paginate if the ui appears to be
             # interactive, the user didn't say HGPLAIN or
             # HGPLAINEXCEPT=pager, and the user didn't specify --debug.
             return
 
         pagercmd = self.config('pager', 'pager', rcutil.fallbackpager)
         if not pagercmd:
             return
 
         pagerenv = {}
         for name, value in rcutil.defaultpagerenv().items():
             if name not in encoding.environ:
                 pagerenv[name] = value
 
         self.debug('starting pager for command %r\n' % command)
         self.flush()
 
         wasformatted = self.formatted()
         if util.safehasattr(signal, "SIGPIPE"):
             signal.signal(signal.SIGPIPE, _catchterm)
         if self._runpager(pagercmd, pagerenv):
             self.pageractive = True
             # Preserve the formatted-ness of the UI. This is important
             # because we mess with stdout, which might confuse
             # auto-detection of things being formatted.
             self.setconfig('ui', 'formatted', wasformatted, 'pager')
             self.setconfig('ui', 'interactive', False, 'pager')
 
             # If pagermode differs from color.mode, reconfigure color now that
             # pageractive is set.
             cm = self._colormode
             if cm != self.config('color', 'pagermode', cm):
                 color.setup(self)
         else:
             # If the pager can't be spawned in dispatch when --pager=on is
             # given, don't try again when the command runs, to avoid a duplicate
             # warning about a missing pager command.
             self.disablepager()
 
     def _runpager(self, command, env=None):
         """Actually start the pager and set up file descriptors.
 
         This is separate in part so that extensions (like chg) can
         override how a pager is invoked.
         """
         if command == 'cat':
             # Save ourselves some work.
             return False
         # If the command doesn't contain any of these characters, we
         # assume it's a binary and exec it directly. This means for
         # simple pager command configurations, we can degrade
         # gracefully and tell the user about their broken pager.
         shell = any(c in command for c in "|&;<>()$`\\\"' \t\n*?[#~=%")
 
         if pycompat.iswindows and not shell:
             # Window's built-in `more` cannot be invoked with shell=False, but
             # its `more.com` can.  Hide this implementation detail from the
             # user so we can also get sane bad PAGER behavior.  MSYS has
             # `more.exe`, so do a cmd.exe style resolution of the executable to
             # determine which one to use.
             fullcmd = procutil.findexe(command)
             if not fullcmd:
                 self.warn(_("missing pager command '%s', skipping pager\n")
                           % command)
                 return False
 
             command = fullcmd
 
         try:
             pager = subprocess.Popen(
                 command, shell=shell, bufsize=-1,
                 close_fds=procutil.closefds, stdin=subprocess.PIPE,
                 stdout=procutil.stdout, stderr=procutil.stderr,
                 env=procutil.shellenviron(env))
         except OSError as e:
             if e.errno == errno.ENOENT and not shell:
                 self.warn(_("missing pager command '%s', skipping pager\n")
                           % command)
                 return False
             raise
 
         # back up original file descriptors
         stdoutfd = os.dup(procutil.stdout.fileno())
         stderrfd = os.dup(procutil.stderr.fileno())
 
         os.dup2(pager.stdin.fileno(), procutil.stdout.fileno())
         if self._isatty(procutil.stderr):
             os.dup2(pager.stdin.fileno(), procutil.stderr.fileno())
 
         @self.atexit
         def killpager():
             if util.safehasattr(signal, "SIGINT"):
                 signal.signal(signal.SIGINT, signal.SIG_IGN)
             # restore original fds, closing pager.stdin copies in the process
             os.dup2(stdoutfd, procutil.stdout.fileno())
             os.dup2(stderrfd, procutil.stderr.fileno())
             pager.stdin.close()
             pager.wait()
 
         return True
 
     @property
     def _exithandlers(self):
         return _reqexithandlers
 
     def atexit(self, func, *args, **kwargs):
         '''register a function to run after dispatching a request
 
         Handlers do not stay registered across request boundaries.'''
         self._exithandlers.append((func, args, kwargs))
         return func
 
     def interface(self, feature):
         """what interface to use for interactive console features?
 
         The interface is controlled by the value of `ui.interface` but also by
         the value of feature-specific configuration. For example:
 
         ui.interface.histedit = text
         ui.interface.chunkselector = curses
 
         Here the features are "histedit" and "chunkselector".
 
         The configuration above means that the default interfaces for commands
         is curses, the interface for histedit is text and the interface for
         selecting chunk is crecord (the best curses interface available).
 
         Consider the following example:
         ui.interface = curses
         ui.interface.histedit = text
 
         Then histedit will use the text interface and chunkselector will use
         the default curses interface (crecord at the moment).
         """
         alldefaults = frozenset(["text", "curses"])
 
         featureinterfaces = {
             "chunkselector": [
                 "text",
                 "curses",
             ]
         }
 
         # Feature-specific interface
         if feature not in featureinterfaces.keys():
             # Programming error, not user error
             raise ValueError("Unknown feature requested %s" % feature)
 
         availableinterfaces = frozenset(featureinterfaces[feature])
         if alldefaults > availableinterfaces:
             # Programming error, not user error. We need a use case to
             # define the right thing to do here.
             raise ValueError(
                 "Feature %s does not handle all default interfaces" %
                 feature)
 
         if self.plain():
             return "text"
 
         # Default interface for all the features
         defaultinterface = "text"
         i = self.config("ui", "interface")
         if i in alldefaults:
             defaultinterface = i
 
         choseninterface = defaultinterface
         f = self.config("ui", "interface.%s" % feature)
         if f in availableinterfaces:
             choseninterface = f
 
         if i is not None and defaultinterface != i:
             if f is not None:
                 self.warn(_("invalid value for ui.interface: %s\n") %
                           (i,))
             else:
                 self.warn(_("invalid value for ui.interface: %s (using %s)\n") %
                          (i, choseninterface))
         if f is not None and choseninterface != f:
             self.warn(_("invalid value for ui.interface.%s: %s (using %s)\n") %
                       (feature, f, choseninterface))
 
         return choseninterface
 
     def interactive(self):
         '''is interactive input allowed?
 
         An interactive session is a session where input can be reasonably read
         from `sys.stdin'. If this function returns false, any attempt to read
         from stdin should fail with an error, unless a sensible default has been
         specified.
 
         Interactiveness is triggered by the value of the `ui.interactive'
         configuration variable or - if it is unset - when `sys.stdin' points
         to a terminal device.
 
         This function refers to input only; for output, see `ui.formatted()'.
         '''
         i = self.configbool("ui", "interactive")
         if i is None:
             # some environments replace stdin without implementing isatty
             # usually those are non-interactive
             return self._isatty(self.fin)
 
         return i
 
     def termwidth(self):
         '''how wide is the terminal in columns?
         '''
         if 'COLUMNS' in encoding.environ:
             try:
                 return int(encoding.environ['COLUMNS'])
             except ValueError:
                 pass
         return scmutil.termsize(self)[0]
 
     def formatted(self):
         '''should formatted output be used?
 
         It is often desirable to format the output to suite the output medium.
         Examples of this are truncating long lines or colorizing messages.
         However, this is not often not desirable when piping output into other
         utilities, e.g. `grep'.
 
         Formatted output is triggered by the value of the `ui.formatted'
         configuration variable or - if it is unset - when `sys.stdout' points
         to a terminal device. Please note that `ui.formatted' should be
         considered an implementation detail; it is not intended for use outside
         Mercurial or its extensions.
 
         This function refers to output only; for input, see `ui.interactive()'.
         This function always returns false when in plain mode, see `ui.plain()'.
         '''
         if self.plain():
             return False
 
         i = self.configbool("ui", "formatted")
         if i is None:
             # some environments replace stdout without implementing isatty
             # usually those are non-interactive
             return self._isatty(self.fout)
 
         return i
 
     def _readline(self):
         # Replacing stdin/stdout temporarily is a hard problem on Python 3
         # because they have to be text streams with *no buffering*. Instead,
         # we use rawinput() only if call_readline() will be invoked by
         # PyOS_Readline(), so no I/O will be made at Python layer.
         usereadline = (self._isatty(self.fin) and self._isatty(self.fout)
                        and procutil.isstdin(self.fin)
                        and procutil.isstdout(self.fout))
         if usereadline:
             try:
                 # magically add command line editing support, where
                 # available
                 import readline
                 # force demandimport to really load the module
                 readline.read_history_file
                 # windows sometimes raises something other than ImportError
             except Exception:
                 usereadline = False
 
         # prompt ' ' must exist; otherwise readline may delete entire line
         # - http://bugs.python.org/issue12833
         with self.timeblockedsection('stdio'):
             if usereadline:
                 line = encoding.strtolocal(pycompat.rawinput(r' '))
                 # When stdin is in binary mode on Windows, it can cause
                 # raw_input() to emit an extra trailing carriage return
                 if pycompat.oslinesep == b'\r\n' and line.endswith(b'\r'):
                     line = line[:-1]
             else:
                 self.fout.write(b' ')
                 self.fout.flush()
                 line = self.fin.readline()
                 if not line:
                     raise EOFError
                 line = line.rstrip(pycompat.oslinesep)
 
         return line
 
     def prompt(self, msg, default="y"):
         """Prompt user with msg, read response.
         If ui is not interactive, the default is returned.
         """
         if not self.interactive():
             self.write(msg, ' ', default or '', "\n")
             return default
         self._writenobuf(msg, label='ui.prompt')
         self.flush()
         try:
             r = self._readline()
             if not r:
                 r = default
             if self.configbool('ui', 'promptecho'):
                 self.write(r, "\n")
             return r
         except EOFError:
             raise error.ResponseExpected()
 
     @staticmethod
     def extractchoices(prompt):
         """Extract prompt message and list of choices from specified prompt.
 
         This returns tuple "(message, choices)", and "choices" is the
         list of tuple "(response character, text without &)".
 
         >>> ui.extractchoices(b"awake? $$ &Yes $$ &No")
         ('awake? ', [('y', 'Yes'), ('n', 'No')])
         >>> ui.extractchoices(b"line\\nbreak? $$ &Yes $$ &No")
         ('line\\nbreak? ', [('y', 'Yes'), ('n', 'No')])
         >>> ui.extractchoices(b"want lots of $$money$$?$$Ye&s$$N&o")
         ('want lots of $$money$$?', [('s', 'Yes'), ('o', 'No')])
         """
 
         # Sadly, the prompt string may have been built with a filename
         # containing "$$" so let's try to find the first valid-looking
         # prompt to start parsing. Sadly, we also can't rely on
         # choices containing spaces, ASCII, or basically anything
         # except an ampersand followed by a character.
         m = re.match(br'(?s)(.+?)\$\$([^\$]*&[^ \$].*)', prompt)
         msg = m.group(1)
         choices = [p.strip(' ') for p in m.group(2).split('$$')]
         def choicetuple(s):
             ampidx = s.index('&')
             return s[ampidx + 1:ampidx + 2].lower(), s.replace('&', '', 1)
         return (msg, [choicetuple(s) for s in choices])
 
     def promptchoice(self, prompt, default=0):
         """Prompt user with a message, read response, and ensure it matches
         one of the provided choices. The prompt is formatted as follows:
 
            "would you like fries with that (Yn)? $$ &Yes $$ &No"
 
         The index of the choice is returned. Responses are case
         insensitive. If ui is not interactive, the default is
         returned.
         """
 
         msg, choices = self.extractchoices(prompt)
         resps = [r for r, t in choices]
         while True:
             r = self.prompt(msg, resps[default])
             if r.lower() in resps:
                 return resps.index(r.lower())
             self.write(_("unrecognized response\n"))
 
     def getpass(self, prompt=None, default=None):
         if not self.interactive():
             return default
         try:
             self.write_err(self.label(prompt or _('password: '), 'ui.prompt'))
             # disable getpass() only if explicitly specified. it's still valid
             # to interact with tty even if fin is not a tty.
             with self.timeblockedsection('stdio'):
                 if self.configbool('ui', 'nontty'):
                     l = self.fin.readline()
                     if not l:
                         raise EOFError
                     return l.rstrip('\n')
                 else:
                     return getpass.getpass('')
         except EOFError:
             raise error.ResponseExpected()
     def status(self, *msg, **opts):
         '''write status message to output (if ui.quiet is False)
 
         This adds an output label of "ui.status".
         '''
         if not self.quiet:
             opts[r'label'] = opts.get(r'label', '') + ' ui.status'
             self.write(*msg, **opts)
     def warn(self, *msg, **opts):
         '''write warning message to output (stderr)
 
         This adds an output label of "ui.warning".
         '''
         opts[r'label'] = opts.get(r'label', '') + ' ui.warning'
         self.write_err(*msg, **opts)
     def note(self, *msg, **opts):
         '''write note to output (if ui.verbose is True)
 
         This adds an output label of "ui.note".
         '''
         if self.verbose:
             opts[r'label'] = opts.get(r'label', '') + ' ui.note'
             self.write(*msg, **opts)
     def debug(self, *msg, **opts):
         '''write debug message to output (if ui.debugflag is True)
 
         This adds an output label of "ui.debug".
         '''
         if self.debugflag:
             opts[r'label'] = opts.get(r'label', '') + ' ui.debug'
             self.write(*msg, **opts)
 
     def edit(self, text, user, extra=None, editform=None, pending=None,
              repopath=None, action=None):
         if action is None:
             self.develwarn('action is None but will soon be a required '
                            'parameter to ui.edit()')
         extra_defaults = {
             'prefix': 'editor',
             'suffix': '.txt',
         }
         if extra is not None:
             if extra.get('suffix') is not None:
                 self.develwarn('extra.suffix is not None but will soon be '
                                'ignored by ui.edit()')
             extra_defaults.update(extra)
         extra = extra_defaults
 
         if action == 'diff':
             suffix = '.diff'
         elif action:
             suffix = '.%s.hg.txt' % action
         else:
             suffix = extra['suffix']
 
         rdir = None
         if self.configbool('experimental', 'editortmpinhg'):
             rdir = repopath
         (fd, name) = pycompat.mkstemp(prefix='hg-' + extra['prefix'] + '-',
                                       suffix=suffix,
                                       dir=rdir)
         try:
             f = os.fdopen(fd, r'wb')
             f.write(util.tonativeeol(text))
             f.close()
 
             environ = {'HGUSER': user}
             if 'transplant_source' in extra:
                 environ.update({'HGREVISION': hex(extra['transplant_source'])})
             for label in ('intermediate-source', 'source', 'rebase_source'):
                 if label in extra:
                     environ.update({'HGREVISION': extra[label]})
                     break
             if editform:
                 environ.update({'HGEDITFORM': editform})
             if pending:
                 environ.update({'HG_PENDING': pending})
 
             editor = self.geteditor()
 
             self.system("%s \"%s\"" % (editor, name),
                         environ=environ,
                         onerr=error.Abort, errprefix=_("edit failed"),
                         blockedtag='editor')
 
             f = open(name, r'rb')
             t = util.fromnativeeol(f.read())
             f.close()
         finally:
             os.unlink(name)
 
         return t
 
     def system(self, cmd, environ=None, cwd=None, onerr=None, errprefix=None,
                blockedtag=None):
         '''execute shell command with appropriate output stream. command
         output will be redirected if fout is not stdout.
 
         if command fails and onerr is None, return status, else raise onerr
         object as exception.
         '''
         if blockedtag is None:
             # Long cmds tend to be because of an absolute path on cmd. Keep
             # the tail end instead
             cmdsuffix = cmd.translate(None, _keepalnum)[-85:]
             blockedtag = 'unknown_system_' + cmdsuffix
         out = self.fout
         if any(s[1] for s in self._bufferstates):
             out = self
         with self.timeblockedsection(blockedtag):
             rc = self._runsystem(cmd, environ=environ, cwd=cwd, out=out)
         if rc and onerr:
             errmsg = '%s %s' % (os.path.basename(cmd.split(None, 1)[0]),
                                 procutil.explainexit(rc))
             if errprefix:
                 errmsg = '%s: %s' % (errprefix, errmsg)
             raise onerr(errmsg)
         return rc
 
     def _runsystem(self, cmd, environ, cwd, out):
         """actually execute the given shell command (can be overridden by
         extensions like chg)"""
         return procutil.system(cmd, environ=environ, cwd=cwd, out=out)
 
     def traceback(self, exc=None, force=False):
         '''print exception traceback if traceback printing enabled or forced.
         only to call in exception handler. returns true if traceback
         printed.'''
         if self.tracebackflag or force:
             if exc is None:
                 exc = sys.exc_info()
             cause = getattr(exc[1], 'cause', None)
 
             if cause is not None:
                 causetb = traceback.format_tb(cause[2])
                 exctb = traceback.format_tb(exc[2])
                 exconly = traceback.format_exception_only(cause[0], cause[1])
 
                 # exclude frame where 'exc' was chained and rethrown from exctb
                 self.write_err('Traceback (most recent call last):\n',
                                ''.join(exctb[:-1]),
                                ''.join(causetb),
                                ''.join(exconly))
             else:
                 output = traceback.format_exception(exc[0], exc[1], exc[2])
                 self.write_err(encoding.strtolocal(r''.join(output)))
         return self.tracebackflag or force
 
     def geteditor(self):
         '''return editor to use'''
         if pycompat.sysplatform == 'plan9':
             # vi is the MIPS instruction simulator on Plan 9. We
             # instead default to E to plumb commit messages to
             # avoid confusion.
             editor = 'E'
         else:
             editor = 'vi'
         return (encoding.environ.get("HGEDITOR") or
                 self.config("ui", "editor", editor))
 
     @util.propertycache
     def _progbar(self):
         """setup the progbar singleton to the ui object"""
         if (self.quiet or self.debugflag
                 or self.configbool('progress', 'disable')
                 or not progress.shouldprint(self)):
             return None
         return getprogbar(self)
 
     def _progclear(self):
         """clear progress bar output if any. use it before any output"""
         if not haveprogbar(): # nothing loaded yet
             return
         if self._progbar is not None and self._progbar.printed:
             self._progbar.clear()
 
     def progress(self, topic, pos, item="", unit="", total=None):
         '''show a progress message
 
         By default a textual progress bar will be displayed if an operation
         takes too long. 'topic' is the current operation, 'item' is a
         non-numeric marker of the current position (i.e. the currently
         in-process file), 'pos' is the current numeric position (i.e.
         revision, bytes, etc.), unit is a corresponding unit label,
         and total is the highest expected pos.
 
         Multiple nested topics may be active at a time.
 
         All topics should be marked closed by setting pos to None at
         termination.
         '''
         if self._progbar is not None:
             self._progbar.progress(topic, pos, item=item, unit=unit,
                                    total=total)
         if pos is None or not self.configbool('progress', 'debug'):
             return
 
         if unit:
             unit = ' ' + unit
         if item:
             item = ' ' + item
 
         if total:
             pct = 100.0 * pos / total
             self.debug('%s:%s %d/%d%s (%4.2f%%)\n'
                      % (topic, item, pos, total, unit, pct))
         else:
             self.debug('%s:%s %d%s\n' % (topic, item, pos, unit))
 
+    def makeprogress(self, topic, unit="", total=None):
+        '''exists only so low-level modules won't need to import scmutil'''
+        return scmutil.progress(self, topic, unit, total)
+
     def log(self, service, *msg, **opts):
         '''hook for logging facility extensions
 
         service should be a readily-identifiable subsystem, which will
         allow filtering.
 
         *msg should be a newline-terminated format string to log, and
         then any values to %-format into that format string.
 
         **opts currently has no defined meanings.
         '''
 
     def label(self, msg, label):
         '''style msg based on supplied label
 
         If some color mode is enabled, this will add the necessary control
         characters to apply such color. In addition, 'debug' color mode adds
         markup showing which label affects a piece of text.
 
         ui.write(s, 'label') is equivalent to
         ui.write(ui.label(s, 'label')).
         '''
         if self._colormode is not None:
             return color.colorlabel(self, msg, label)
         return msg
 
     def develwarn(self, msg, stacklevel=1, config=None):
         """issue a developer warning message
 
         Use 'stacklevel' to report the offender some layers further up in the
         stack.
         """
         if not self.configbool('devel', 'all-warnings'):
             if config is None or not self.configbool('devel', config):
                 return
         msg = 'devel-warn: ' + msg
         stacklevel += 1 # get in develwarn
         if self.tracebackflag:
             util.debugstacktrace(msg, stacklevel, self.ferr, self.fout)
             self.log('develwarn', '%s at:\n%s' %
                      (msg, ''.join(util.getstackframes(stacklevel))))
         else:
             curframe = inspect.currentframe()
             calframe = inspect.getouterframes(curframe, 2)
             fname, lineno, fmsg = calframe[stacklevel][1:4]
             fname, fmsg = pycompat.sysbytes(fname), pycompat.sysbytes(fmsg)
             self.write_err('%s at: %s:%d (%s)\n'
                            % (msg, fname, lineno, fmsg))
             self.log('develwarn', '%s at: %s:%d (%s)\n',
                      msg, fname, lineno, fmsg)
             curframe = calframe = None  # avoid cycles
 
     def deprecwarn(self, msg, version, stacklevel=2):
         """issue a deprecation warning
 
         - msg: message explaining what is deprecated and how to upgrade,
         - version: last version where the API will be supported,
         """
         if not (self.configbool('devel', 'all-warnings')
                 or self.configbool('devel', 'deprec-warn')):
             return
         msg += ("\n(compatibility will be dropped after Mercurial-%s,"
                 " update your code.)") % version
         self.develwarn(msg, stacklevel=stacklevel, config='deprec-warn')
 
     def exportableenviron(self):
         """The environment variables that are safe to export, e.g. through
         hgweb.
         """
         return self._exportableenviron
 
     @contextlib.contextmanager
     def configoverride(self, overrides, source=""):
         """Context manager for temporary config overrides
         `overrides` must be a dict of the following structure:
         {(section, name) : value}"""
         backups = {}
         try:
             for (section, name), value in overrides.items():
                 backups[(section, name)] = self.backupconfig(section, name)
                 self.setconfig(section, name, value, source)
             yield
         finally:
             for __, backup in backups.items():
                 self.restoreconfig(backup)
             # just restoring ui.quiet config to the previous value is not enough
             # as it does not update ui.quiet class member
             if ('ui', 'quiet') in overrides:
                 self.fixconfig(section='ui')
 
 class paths(dict):
     """Represents a collection of paths and their configs.
 
     Data is initially derived from ui instances and the config files they have
     loaded.
     """
     def __init__(self, ui):
         dict.__init__(self)
 
         for name, loc in ui.configitems('paths', ignoresub=True):
             # No location is the same as not existing.
             if not loc:
                 continue
             loc, sub = ui.configsuboptions('paths', name)
             self[name] = path(ui, name, rawloc=loc, suboptions=sub)
 
     def getpath(self, name, default=None):
         """Return a ``path`` from a string, falling back to default.
 
         ``name`` can be a named path or locations. Locations are filesystem
         paths or URIs.
 
         Returns None if ``name`` is not a registered path, a URI, or a local
         path to a repo.
         """
         # Only fall back to default if no path was requested.
         if name is None:
             if not default:
                 default = ()
             elif not isinstance(default, (tuple, list)):
                 default = (default,)
             for k in default:
                 try:
                     return self[k]
                 except KeyError:
                     continue
             return None
 
         # Most likely empty string.
         # This may need to raise in the future.
         if not name:
             return None
 
         try:
             return self[name]
         except KeyError:
             # Try to resolve as a local path or URI.
             try:
                 # We don't pass sub-options in, so no need to pass ui instance.
                 return path(None, None, rawloc=name)
             except ValueError:
                 raise error.RepoError(_('repository %s does not exist') %
                                         name)
 
 _pathsuboptions = {}
 
 def pathsuboption(option, attr):
     """Decorator used to declare a path sub-option.
 
     Arguments are the sub-option name and the attribute it should set on
     ``path`` instances.
 
     The decorated function will receive as arguments a ``ui`` instance,
     ``path`` instance, and the string value of this option from the config.
     The function should return the value that will be set on the ``path``
     instance.
 
     This decorator can be used to perform additional verification of
     sub-options and to change the type of sub-options.
     """
     def register(func):
         _pathsuboptions[option] = (attr, func)
         return func
     return register
 
 @pathsuboption('pushurl', 'pushloc')
 def pushurlpathoption(ui, path, value):
     u = util.url(value)
     # Actually require a URL.
     if not u.scheme:
         ui.warn(_('(paths.%s:pushurl not a URL; ignoring)\n') % path.name)
         return None
 
     # Don't support the #foo syntax in the push URL to declare branch to
     # push.
     if u.fragment:
         ui.warn(_('("#fragment" in paths.%s:pushurl not supported; '
                   'ignoring)\n') % path.name)
         u.fragment = None
 
     return bytes(u)
 
 @pathsuboption('pushrev', 'pushrev')
 def pushrevpathoption(ui, path, value):
     return value
 
 class path(object):
     """Represents an individual path and its configuration."""
 
     def __init__(self, ui, name, rawloc=None, suboptions=None):
         """Construct a path from its config options.
 
         ``ui`` is the ``ui`` instance the path is coming from.
         ``name`` is the symbolic name of the path.
         ``rawloc`` is the raw location, as defined in the config.
         ``pushloc`` is the raw locations pushes should be made to.
 
         If ``name`` is not defined, we require that the location be a) a local
         filesystem path with a .hg directory or b) a URL. If not,
         ``ValueError`` is raised.
         """
         if not rawloc:
             raise ValueError('rawloc must be defined')
 
         # Locations may define branches via syntax <base>#<branch>.
         u = util.url(rawloc)
         branch = None
         if u.fragment:
             branch = u.fragment
             u.fragment = None
 
         self.url = u
         self.branch = branch
 
         self.name = name
         self.rawloc = rawloc
         self.loc = '%s' % u
 
         # When given a raw location but not a symbolic name, validate the
         # location is valid.
         if not name and not u.scheme and not self._isvalidlocalpath(self.loc):
             raise ValueError('location is not a URL or path to a local '
                              'repo: %s' % rawloc)
 
         suboptions = suboptions or {}
 
         # Now process the sub-options. If a sub-option is registered, its
         # attribute will always be present. The value will be None if there
         # was no valid sub-option.
         for suboption, (attr, func) in _pathsuboptions.iteritems():
             if suboption not in suboptions:
                 setattr(self, attr, None)
                 continue
 
             value = func(ui, self, suboptions[suboption])
             setattr(self, attr, value)
 
     def _isvalidlocalpath(self, path):
         """Returns True if the given path is a potentially valid repository.
         This is its own function so that extensions can change the definition of
         'valid' in this case (like when pulling from a git repo into a hg
         one)."""
         return os.path.isdir(os.path.join(path, '.hg'))
 
     @property
     def suboptions(self):
         """Return sub-options and their values for this path.
 
         This is intended to be used for presentation purposes.
         """
         d = {}
         for subopt, (attr, _func) in _pathsuboptions.iteritems():
             value = getattr(self, attr)
             if value is not None:
                 d[subopt] = value
         return d
 
 # we instantiate one globally shared progress bar to avoid
 # competing progress bars when multiple UI objects get created
 _progresssingleton = None
 
 def getprogbar(ui):
     global _progresssingleton
     if _progresssingleton is None:
         # passing 'ui' object to the singleton is fishy,
         # this is how the extension used to work but feel free to rework it.
         _progresssingleton = progress.progbar(ui)
     return _progresssingleton
 
 def haveprogbar():
     return _progresssingleton is not None