curses: do not setlocale() at import time (issue5261)

setlocale() can break date formatting/parsing functions because they are
locale dependent. We should avoid doing setlocale() as possible.

This patch moves setlocale() just before curses.wrapper(), which function
is documented to "initialize curses." I don't know the details about the
curses initialization, but I *think* this would work as well.

Maybe we can extract a curses setup function later.

https://www.mercurial-scm.org/pipermail/mercurial-devel/2019-February/128788.html

hgext/histedit.py

@@ -1,2326 +1,2324 b''
 # histedit.py - interactive history editing for mercurial
 #
 # Copyright 2009 Augie Fackler <[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.
 """interactive history editing
 
 With this extension installed, Mercurial gains one new command: histedit. Usage
 is as follows, assuming the following history::
 
  @  3[tip]   7c2fd3b9020c   2009-04-27 18:04 -0500   durin42
  |    Add delta
  |
  o  2   030b686bedc4   2009-04-27 18:04 -0500   durin42
  |    Add gamma
  |
  o  1   c561b4e977df   2009-04-27 18:04 -0500   durin42
  |    Add beta
  |
  o  0   d8d2fcd0e319   2009-04-27 18:04 -0500   durin42
       Add alpha
 
 If you were to run ``hg histedit c561b4e977df``, you would see the following
 file open in your editor::
 
  pick c561b4e977df Add beta
  pick 030b686bedc4 Add gamma
  pick 7c2fd3b9020c Add delta
 
  # Edit history between c561b4e977df and 7c2fd3b9020c
  #
  # Commits are listed from least to most recent
  #
  # Commands:
  #  p, pick = use commit
  #  e, edit = use commit, but stop for amending
  #  f, fold = use commit, but combine it with the one above
  #  r, roll = like fold, but discard this commit's description and date
  #  d, drop = remove commit from history
  #  m, mess = edit commit message without changing commit content
  #  b, base = checkout changeset and apply further changesets from there
  #
 
 In this file, lines beginning with ``#`` are ignored. You must specify a rule
 for each revision in your history. For example, if you had meant to add gamma
 before beta, and then wanted to add delta in the same revision as beta, you
 would reorganize the file to look like this::
 
  pick 030b686bedc4 Add gamma
  pick c561b4e977df Add beta
  fold 7c2fd3b9020c Add delta
 
  # Edit history between c561b4e977df and 7c2fd3b9020c
  #
  # Commits are listed from least to most recent
  #
  # Commands:
  #  p, pick = use commit
  #  e, edit = use commit, but stop for amending
  #  f, fold = use commit, but combine it with the one above
  #  r, roll = like fold, but discard this commit's description and date
  #  d, drop = remove commit from history
  #  m, mess = edit commit message without changing commit content
  #  b, base = checkout changeset and apply further changesets from there
  #
 
 At which point you close the editor and ``histedit`` starts working. When you
 specify a ``fold`` operation, ``histedit`` will open an editor when it folds
 those revisions together, offering you a chance to clean up the commit message::
 
  Add beta
  ***
  Add delta
 
 Edit the commit message to your liking, then close the editor. The date used
 for the commit will be the later of the two commits' dates. For this example,
 let's assume that the commit message was changed to ``Add beta and delta.``
 After histedit has run and had a chance to remove any old or temporary
 revisions it needed, the history looks like this::
 
  @  2[tip]   989b4d060121   2009-04-27 18:04 -0500   durin42
  |    Add beta and delta.
  |
  o  1   081603921c3f   2009-04-27 18:04 -0500   durin42
  |    Add gamma
  |
  o  0   d8d2fcd0e319   2009-04-27 18:04 -0500   durin42
       Add alpha
 
 Note that ``histedit`` does *not* remove any revisions (even its own temporary
 ones) until after it has completed all the editing operations, so it will
 probably perform several strip operations when it's done. For the above example,
 it had to run strip twice. Strip can be slow depending on a variety of factors,
 so you might need to be a little patient. You can choose to keep the original
 revisions by passing the ``--keep`` flag.
 
 The ``edit`` operation will drop you back to a command prompt,
 allowing you to edit files freely, or even use ``hg record`` to commit
 some changes as a separate commit. When you're done, any remaining
 uncommitted changes will be committed as well. When done, run ``hg
 histedit --continue`` to finish this step. If there are uncommitted
 changes, you'll be prompted for a new commit message, but the default
 commit message will be the original message for the ``edit`` ed
 revision, and the date of the original commit will be preserved.
 
 The ``message`` operation will give you a chance to revise a commit
 message without changing the contents. It's a shortcut for doing
 ``edit`` immediately followed by `hg histedit --continue``.
 
 If ``histedit`` encounters a conflict when moving a revision (while
 handling ``pick`` or ``fold``), it'll stop in a similar manner to
 ``edit`` with the difference that it won't prompt you for a commit
 message when done. If you decide at this point that you don't like how
 much work it will be to rearrange history, or that you made a mistake,
 you can use ``hg histedit --abort`` to abandon the new changes you
 have made and return to the state before you attempted to edit your
 history.
 
 If we clone the histedit-ed example repository above and add four more
 changes, such that we have the following history::
 
    @  6[tip]   038383181893   2009-04-27 18:04 -0500   stefan
    |    Add theta
    |
    o  5   140988835471   2009-04-27 18:04 -0500   stefan
    |    Add eta
    |
    o  4   122930637314   2009-04-27 18:04 -0500   stefan
    |    Add zeta
    |
    o  3   836302820282   2009-04-27 18:04 -0500   stefan
    |    Add epsilon
    |
    o  2   989b4d060121   2009-04-27 18:04 -0500   durin42
    |    Add beta and delta.
    |
    o  1   081603921c3f   2009-04-27 18:04 -0500   durin42
    |    Add gamma
    |
    o  0   d8d2fcd0e319   2009-04-27 18:04 -0500   durin42
         Add alpha
 
 If you run ``hg histedit --outgoing`` on the clone then it is the same
 as running ``hg histedit 836302820282``. If you need plan to push to a
 repository that Mercurial does not detect to be related to the source
 repo, you can add a ``--force`` option.
 
 Config
 ------
 
 Histedit rule lines are truncated to 80 characters by default. You
 can customize this behavior by setting a different length in your
 configuration file::
 
   [histedit]
   linelen = 120      # truncate rule lines at 120 characters
 
 The summary of a change can be customized as well::
 
   [histedit]
   summary-template = '{rev} {bookmarks} {desc|firstline}'
 
 The customized summary should be kept short enough that rule lines
 will fit in the configured line length. See above if that requires
 customization.
 
 ``hg histedit`` attempts to automatically choose an appropriate base
 revision to use. To change which base revision is used, define a
 revset in your configuration file::
 
   [histedit]
   defaultrev = only(.) & draft()
 
 By default each edited revision needs to be present in histedit commands.
 To remove revision you need to use ``drop`` operation. You can configure
 the drop to be implicit for missing commits by adding::
 
   [histedit]
   dropmissing = True
 
 By default, histedit will close the transaction after each action. For
 performance purposes, you can configure histedit to use a single transaction
 across the entire histedit. WARNING: This setting introduces a significant risk
 of losing the work you've done in a histedit if the histedit aborts
 unexpectedly::
 
   [histedit]
   singletransaction = True
 
 """
 
 from __future__ import absolute_import
 
 # chistedit dependencies that are not available everywhere
 try:
     import fcntl
     import termios
 except ImportError:
     fcntl = None
     termios = None
 
 import functools
+import locale
 import os
 import struct
 
 from mercurial.i18n import _
 from mercurial import (
     bundle2,
     cmdutil,
     context,
     copies,
     destutil,
     discovery,
     error,
     exchange,
     extensions,
     hg,
     logcmdutil,
     merge as mergemod,
     mergeutil,
     node,
     obsolete,
     pycompat,
     registrar,
     repair,
     scmutil,
     state as statemod,
     util,
 )
 from mercurial.utils import (
     dateutil,
     stringutil,
 )
 
 pickle = util.pickle
 cmdtable = {}
 command = registrar.command(cmdtable)
 
 configtable = {}
 configitem = registrar.configitem(configtable)
 configitem('experimental', 'histedit.autoverb',
     default=False,
 )
 configitem('histedit', 'defaultrev',
     default=None,
 )
 configitem('histedit', 'dropmissing',
     default=False,
 )
 configitem('histedit', 'linelen',
     default=80,
 )
 configitem('histedit', 'singletransaction',
     default=False,
 )
 configitem('ui', 'interface.histedit',
     default=None,
 )
 configitem('histedit', 'summary-template',
            default='{rev} {desc|firstline}')
 
 # Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for
 # extensions which SHIP WITH MERCURIAL. Non-mainline extensions should
 # be specifying the version(s) of Mercurial they are tested with, or
 # leave the attribute unspecified.
 testedwith = 'ships-with-hg-core'
 
 actiontable = {}
 primaryactions = set()
 secondaryactions = set()
 tertiaryactions = set()
 internalactions = set()
 
 def geteditcomment(ui, first, last):
     """ construct the editor comment
     The comment includes::
      - an intro
      - sorted primary commands
      - sorted short commands
      - sorted long commands
      - additional hints
 
     Commands are only included once.
     """
     intro = _("""Edit history between %s and %s
 
 Commits are listed from least to most recent
 
 You can reorder changesets by reordering the lines
 
 Commands:
 """)
     actions = []
     def addverb(v):
         a = actiontable[v]
         lines = a.message.split("\n")
         if len(a.verbs):
             v = ', '.join(sorted(a.verbs, key=lambda v: len(v)))
         actions.append(" %s = %s" % (v, lines[0]))
         actions.extend(['  %s' for l in lines[1:]])
 
     for v in (
          sorted(primaryactions) +
          sorted(secondaryactions) +
          sorted(tertiaryactions)
         ):
         addverb(v)
     actions.append('')
 
     hints = []
     if ui.configbool('histedit', 'dropmissing'):
         hints.append("Deleting a changeset from the list "
                      "will DISCARD it from the edited history!")
 
     lines = (intro % (first, last)).split('\n') + actions + hints
 
     return ''.join(['# %s\n' % l if l else '#\n' for l in lines])
 
 class histeditstate(object):
     def __init__(self, repo):
         self.repo = repo
         self.actions = None
         self.keep = None
         self.topmost = None
         self.parentctxnode = None
         self.lock = None
         self.wlock = None
         self.backupfile = None
         self.stateobj = statemod.cmdstate(repo, 'histedit-state')
         self.replacements = []
 
     def read(self):
         """Load histedit state from disk and set fields appropriately."""
         if not self.stateobj.exists():
             cmdutil.wrongtooltocontinue(self.repo, _('histedit'))
 
         data = self._read()
 
         self.parentctxnode = data['parentctxnode']
         actions = parserules(data['rules'], self)
         self.actions = actions
         self.keep = data['keep']
         self.topmost = data['topmost']
         self.replacements = data['replacements']
         self.backupfile = data['backupfile']
 
     def _read(self):
         fp = self.repo.vfs.read('histedit-state')
         if fp.startswith('v1\n'):
             data = self._load()
             parentctxnode, rules, keep, topmost, replacements, backupfile = data
         else:
             data = pickle.loads(fp)
             parentctxnode, rules, keep, topmost, replacements = data
             backupfile = None
         rules = "\n".join(["%s %s" % (verb, rest) for [verb, rest] in rules])
 
         return {'parentctxnode': parentctxnode, "rules": rules, "keep": keep,
                 "topmost": topmost, "replacements": replacements,
                 "backupfile": backupfile}
 
     def write(self, tr=None):
         if tr:
             tr.addfilegenerator('histedit-state', ('histedit-state',),
                                 self._write, location='plain')
         else:
             with self.repo.vfs("histedit-state", "w") as f:
                 self._write(f)
 
     def _write(self, fp):
         fp.write('v1\n')
         fp.write('%s\n' % node.hex(self.parentctxnode))
         fp.write('%s\n' % node.hex(self.topmost))
         fp.write('%s\n' % ('True' if self.keep else 'False'))
         fp.write('%d\n' % len(self.actions))
         for action in self.actions:
             fp.write('%s\n' % action.tostate())
         fp.write('%d\n' % len(self.replacements))
         for replacement in self.replacements:
             fp.write('%s%s\n' % (node.hex(replacement[0]), ''.join(node.hex(r)
                 for r in replacement[1])))
         backupfile = self.backupfile
         if not backupfile:
             backupfile = ''
         fp.write('%s\n' % backupfile)
 
     def _load(self):
         fp = self.repo.vfs('histedit-state', 'r')
         lines = [l[:-1] for l in fp.readlines()]
 
         index = 0
         lines[index] # version number
         index += 1
 
         parentctxnode = node.bin(lines[index])
         index += 1
 
         topmost = node.bin(lines[index])
         index += 1
 
         keep = lines[index] == 'True'
         index += 1
 
         # Rules
         rules = []
         rulelen = int(lines[index])
         index += 1
         for i in pycompat.xrange(rulelen):
             ruleaction = lines[index]
             index += 1
             rule = lines[index]
             index += 1
             rules.append((ruleaction, rule))
 
         # Replacements
         replacements = []
         replacementlen = int(lines[index])
         index += 1
         for i in pycompat.xrange(replacementlen):
             replacement = lines[index]
             original = node.bin(replacement[:40])
             succ = [node.bin(replacement[i:i + 40]) for i in
                     range(40, len(replacement), 40)]
             replacements.append((original, succ))
             index += 1
 
         backupfile = lines[index]
         index += 1
 
         fp.close()
 
         return parentctxnode, rules, keep, topmost, replacements, backupfile
 
     def clear(self):
         if self.inprogress():
             self.repo.vfs.unlink('histedit-state')
 
     def inprogress(self):
         return self.repo.vfs.exists('histedit-state')
 
 
 class histeditaction(object):
     def __init__(self, state, node):
         self.state = state
         self.repo = state.repo
         self.node = node
 
     @classmethod
     def fromrule(cls, state, rule):
         """Parses the given rule, returning an instance of the histeditaction.
         """
         ruleid = rule.strip().split(' ', 1)[0]
         # ruleid can be anything from rev numbers, hashes, "bookmarks" etc
         # Check for validation of rule ids and get the rulehash
         try:
             rev = node.bin(ruleid)
         except TypeError:
             try:
                 _ctx = scmutil.revsingle(state.repo, ruleid)
                 rulehash = _ctx.hex()
                 rev = node.bin(rulehash)
             except error.RepoLookupError:
                 raise error.ParseError(_("invalid changeset %s") % ruleid)
         return cls(state, rev)
 
     def verify(self, prev, expected, seen):
         """ Verifies semantic correctness of the rule"""
         repo = self.repo
         ha = node.hex(self.node)
         self.node = scmutil.resolvehexnodeidprefix(repo, ha)
         if self.node is None:
             raise error.ParseError(_('unknown changeset %s listed') % ha[:12])
         self._verifynodeconstraints(prev, expected, seen)
 
     def _verifynodeconstraints(self, prev, expected, seen):
         # by default command need a node in the edited list
         if self.node not in expected:
             raise error.ParseError(_('%s "%s" changeset was not a candidate')
                                    % (self.verb, node.short(self.node)),
                                    hint=_('only use listed changesets'))
         # and only one command per node
         if self.node in seen:
             raise error.ParseError(_('duplicated command for changeset %s') %
                                    node.short(self.node))
 
     def torule(self):
         """build a histedit rule line for an action
 
         by default lines are in the form:
         <hash> <rev> <summary>
         """
         ctx = self.repo[self.node]
         ui = self.repo.ui
         summary = cmdutil.rendertemplate(
             ctx, ui.config('histedit', 'summary-template')) or ''
         summary = summary.splitlines()[0]
         line = '%s %s %s' % (self.verb, ctx, summary)
         # trim to 75 columns by default so it's not stupidly wide in my editor
         # (the 5 more are left for verb)
         maxlen = self.repo.ui.configint('histedit', 'linelen')
         maxlen = max(maxlen, 22) # avoid truncating hash
         return stringutil.ellipsis(line, maxlen)
 
     def tostate(self):
         """Print an action in format used by histedit state files
            (the first line is a verb, the remainder is the second)
         """
         return "%s\n%s" % (self.verb, node.hex(self.node))
 
     def run(self):
         """Runs the action. The default behavior is simply apply the action's
         rulectx onto the current parentctx."""
         self.applychange()
         self.continuedirty()
         return self.continueclean()
 
     def applychange(self):
         """Applies the changes from this action's rulectx onto the current
         parentctx, but does not commit them."""
         repo = self.repo
         rulectx = repo[self.node]
         repo.ui.pushbuffer(error=True, labeled=True)
         hg.update(repo, self.state.parentctxnode, quietempty=True)
         repo.ui.popbuffer()
         stats = applychanges(repo.ui, repo, rulectx, {})
         repo.dirstate.setbranch(rulectx.branch())
         if stats.unresolvedcount:
             raise error.InterventionRequired(
                 _('Fix up the change (%s %s)') %
                 (self.verb, node.short(self.node)),
                 hint=_('hg histedit --continue to resume'))
 
     def continuedirty(self):
         """Continues the action when changes have been applied to the working
         copy. The default behavior is to commit the dirty changes."""
         repo = self.repo
         rulectx = repo[self.node]
 
         editor = self.commiteditor()
         commit = commitfuncfor(repo, rulectx)
         if repo.ui.configbool('rewrite', 'update-timestamp'):
             date = dateutil.makedate()
         else:
             date = rulectx.date()
         commit(text=rulectx.description(), user=rulectx.user(),
                date=date, extra=rulectx.extra(), editor=editor)
 
     def commiteditor(self):
         """The editor to be used to edit the commit message."""
         return False
 
     def continueclean(self):
         """Continues the action when the working copy is clean. The default
         behavior is to accept the current commit as the new version of the
         rulectx."""
         ctx = self.repo['.']
         if ctx.node() == self.state.parentctxnode:
             self.repo.ui.warn(_('%s: skipping changeset (no changes)\n') %
                               node.short(self.node))
             return ctx, [(self.node, tuple())]
         if ctx.node() == self.node:
             # Nothing changed
             return ctx, []
         return ctx, [(self.node, (ctx.node(),))]
 
 def commitfuncfor(repo, src):
     """Build a commit function for the replacement of <src>
 
     This function ensure we apply the same treatment to all changesets.
 
     - Add a 'histedit_source' entry in extra.
 
     Note that fold has its own separated logic because its handling is a bit
     different and not easily factored out of the fold method.
     """
     phasemin = src.phase()
     def commitfunc(**kwargs):
         overrides = {('phases', 'new-commit'): phasemin}
         with repo.ui.configoverride(overrides, 'histedit'):
             extra = kwargs.get(r'extra', {}).copy()
             extra['histedit_source'] = src.hex()
             kwargs[r'extra'] = extra
             return repo.commit(**kwargs)
     return commitfunc
 
 def applychanges(ui, repo, ctx, opts):
     """Merge changeset from ctx (only) in the current working directory"""
     wcpar = repo.dirstate.p1()
     if ctx.p1().node() == wcpar:
         # edits are "in place" we do not need to make any merge,
         # just applies changes on parent for editing
         ui.pushbuffer()
         cmdutil.revert(ui, repo, ctx, (wcpar, node.nullid), all=True)
         stats = mergemod.updateresult(0, 0, 0, 0)
         ui.popbuffer()
     else:
         try:
             # ui.forcemerge is an internal variable, do not document
             repo.ui.setconfig('ui', 'forcemerge', opts.get('tool', ''),
                               'histedit')
             stats = mergemod.graft(repo, ctx, ctx.p1(), ['local', 'histedit'])
         finally:
             repo.ui.setconfig('ui', 'forcemerge', '', 'histedit')
     return stats
 
 def collapse(repo, firstctx, lastctx, commitopts, skipprompt=False):
     """collapse the set of revisions from first to last as new one.
 
     Expected commit options are:
         - message
         - date
         - username
     Commit message is edited in all cases.
 
     This function works in memory."""
     ctxs = list(repo.set('%d::%d', firstctx.rev(), lastctx.rev()))
     if not ctxs:
         return None
     for c in ctxs:
         if not c.mutable():
             raise error.ParseError(
                 _("cannot fold into public change %s") % node.short(c.node()))
     base = firstctx.p1()
 
     # commit a new version of the old changeset, including the update
     # collect all files which might be affected
     files = set()
     for ctx in ctxs:
         files.update(ctx.files())
 
     # Recompute copies (avoid recording a -> b -> a)
     copied = copies.pathcopies(base, lastctx)
 
     # prune files which were reverted by the updates
     files = [f for f in files if not cmdutil.samefile(f, lastctx, base)]
     # commit version of these files as defined by head
     headmf = lastctx.manifest()
     def filectxfn(repo, ctx, path):
         if path in headmf:
             fctx = lastctx[path]
             flags = fctx.flags()
             mctx = context.memfilectx(repo, ctx,
                                       fctx.path(), fctx.data(),
                                       islink='l' in flags,
                                       isexec='x' in flags,
                                       copysource=copied.get(path))
             return mctx
         return None
 
     if commitopts.get('message'):
         message = commitopts['message']
     else:
         message = firstctx.description()
     user = commitopts.get('user')
     date = commitopts.get('date')
     extra = commitopts.get('extra')
 
     parents = (firstctx.p1().node(), firstctx.p2().node())
     editor = None
     if not skipprompt:
         editor = cmdutil.getcommiteditor(edit=True, editform='histedit.fold')
     new = context.memctx(repo,
                          parents=parents,
                          text=message,
                          files=files,
                          filectxfn=filectxfn,
                          user=user,
                          date=date,
                          extra=extra,
                          editor=editor)
     return repo.commitctx(new)
 
 def _isdirtywc(repo):
     return repo[None].dirty(missing=True)
 
 def abortdirty():
     raise error.Abort(_('working copy has pending changes'),
         hint=_('amend, commit, or revert them and run histedit '
             '--continue, or abort with histedit --abort'))
 
 def action(verbs, message, priority=False, internal=False):
     def wrap(cls):
         assert not priority or not internal
         verb = verbs[0]
         if priority:
             primaryactions.add(verb)
         elif internal:
             internalactions.add(verb)
         elif len(verbs) > 1:
             secondaryactions.add(verb)
         else:
             tertiaryactions.add(verb)
 
         cls.verb = verb
         cls.verbs = verbs
         cls.message = message
         for verb in verbs:
             actiontable[verb] = cls
         return cls
     return wrap
 
 @action(['pick', 'p'],
         _('use commit'),
         priority=True)
 class pick(histeditaction):
     def run(self):
         rulectx = self.repo[self.node]
         if rulectx.p1().node() == self.state.parentctxnode:
             self.repo.ui.debug('node %s unchanged\n' % node.short(self.node))
             return rulectx, []
 
         return super(pick, self).run()
 
 @action(['edit', 'e'],
         _('use commit, but stop for amending'),
         priority=True)
 class edit(histeditaction):
     def run(self):
         repo = self.repo
         rulectx = repo[self.node]
         hg.update(repo, self.state.parentctxnode, quietempty=True)
         applychanges(repo.ui, repo, rulectx, {})
         raise error.InterventionRequired(
             _('Editing (%s), you may commit or record as needed now.')
             % node.short(self.node),
             hint=_('hg histedit --continue to resume'))
 
     def commiteditor(self):
         return cmdutil.getcommiteditor(edit=True, editform='histedit.edit')
 
 @action(['fold', 'f'],
         _('use commit, but combine it with the one above'))
 class fold(histeditaction):
     def verify(self, prev, expected, seen):
         """ Verifies semantic correctness of the fold rule"""
         super(fold, self).verify(prev, expected, seen)
         repo = self.repo
         if not prev:
             c = repo[self.node].p1()
         elif not prev.verb in ('pick', 'base'):
             return
         else:
             c = repo[prev.node]
         if not c.mutable():
             raise error.ParseError(
                 _("cannot fold into public change %s") % node.short(c.node()))
 
 
     def continuedirty(self):
         repo = self.repo
         rulectx = repo[self.node]
 
         commit = commitfuncfor(repo, rulectx)
         commit(text='fold-temp-revision %s' % node.short(self.node),
                user=rulectx.user(), date=rulectx.date(),
                extra=rulectx.extra())
 
     def continueclean(self):
         repo = self.repo
         ctx = repo['.']
         rulectx = repo[self.node]
         parentctxnode = self.state.parentctxnode
         if ctx.node() == parentctxnode:
             repo.ui.warn(_('%s: empty changeset\n') %
                               node.short(self.node))
             return ctx, [(self.node, (parentctxnode,))]
 
         parentctx = repo[parentctxnode]
         newcommits = set(c.node() for c in repo.set('(%d::. - %d)',
                                                     parentctx.rev(),
                                                     parentctx.rev()))
         if not newcommits:
             repo.ui.warn(_('%s: cannot fold - working copy is not a '
                            'descendant of previous commit %s\n') %
                            (node.short(self.node), node.short(parentctxnode)))
             return ctx, [(self.node, (ctx.node(),))]
 
         middlecommits = newcommits.copy()
         middlecommits.discard(ctx.node())
 
         return self.finishfold(repo.ui, repo, parentctx, rulectx, ctx.node(),
                                middlecommits)
 
     def skipprompt(self):
         """Returns true if the rule should skip the message editor.
 
         For example, 'fold' wants to show an editor, but 'rollup'
         doesn't want to.
         """
         return False
 
     def mergedescs(self):
         """Returns true if the rule should merge messages of multiple changes.
 
         This exists mainly so that 'rollup' rules can be a subclass of
         'fold'.
         """
         return True
 
     def firstdate(self):
         """Returns true if the rule should preserve the date of the first
         change.
 
         This exists mainly so that 'rollup' rules can be a subclass of
         'fold'.
         """
         return False
 
     def finishfold(self, ui, repo, ctx, oldctx, newnode, internalchanges):
         parent = ctx.p1().node()
         hg.updaterepo(repo, parent, overwrite=False)
         ### prepare new commit data
         commitopts = {}
         commitopts['user'] = ctx.user()
         # commit message
         if not self.mergedescs():
             newmessage = ctx.description()
         else:
             newmessage = '\n***\n'.join(
                 [ctx.description()] +
                 [repo[r].description() for r in internalchanges] +
                 [oldctx.description()]) + '\n'
         commitopts['message'] = newmessage
         # date
         if self.firstdate():
             commitopts['date'] = ctx.date()
         else:
             commitopts['date'] = max(ctx.date(), oldctx.date())
         # if date is to be updated to current
         if ui.configbool('rewrite', 'update-timestamp'):
             commitopts['date'] = dateutil.makedate()
 
         extra = ctx.extra().copy()
         # histedit_source
         # note: ctx is likely a temporary commit but that the best we can do
         #       here. This is sufficient to solve issue3681 anyway.
         extra['histedit_source'] = '%s,%s' % (ctx.hex(), oldctx.hex())
         commitopts['extra'] = extra
         phasemin = max(ctx.phase(), oldctx.phase())
         overrides = {('phases', 'new-commit'): phasemin}
         with repo.ui.configoverride(overrides, 'histedit'):
             n = collapse(repo, ctx, repo[newnode], commitopts,
                          skipprompt=self.skipprompt())
         if n is None:
             return ctx, []
         hg.updaterepo(repo, n, overwrite=False)
         replacements = [(oldctx.node(), (newnode,)),
                         (ctx.node(), (n,)),
                         (newnode, (n,)),
                        ]
         for ich in internalchanges:
             replacements.append((ich, (n,)))
         return repo[n], replacements
 
 @action(['base', 'b'],
         _('checkout changeset and apply further changesets from there'))
 class base(histeditaction):
 
     def run(self):
         if self.repo['.'].node() != self.node:
             mergemod.update(self.repo, self.node, branchmerge=False, force=True)
         return self.continueclean()
 
     def continuedirty(self):
         abortdirty()
 
     def continueclean(self):
         basectx = self.repo['.']
         return basectx, []
 
     def _verifynodeconstraints(self, prev, expected, seen):
         # base can only be use with a node not in the edited set
         if self.node in expected:
             msg = _('%s "%s" changeset was an edited list candidate')
             raise error.ParseError(
                 msg % (self.verb, node.short(self.node)),
                 hint=_('base must only use unlisted changesets'))
 
 @action(['_multifold'],
         _(
     """fold subclass used for when multiple folds happen in a row
 
     We only want to fire the editor for the folded message once when
     (say) four changes are folded down into a single change. This is
     similar to rollup, but we should preserve both messages so that
     when the last fold operation runs we can show the user all the
     commit messages in their editor.
     """),
         internal=True)
 class _multifold(fold):
     def skipprompt(self):
         return True
 
 @action(["roll", "r"],
         _("like fold, but discard this commit's description and date"))
 class rollup(fold):
     def mergedescs(self):
         return False
 
     def skipprompt(self):
         return True
 
     def firstdate(self):
         return True
 
 @action(["drop", "d"],
         _('remove commit from history'))
 class drop(histeditaction):
     def run(self):
         parentctx = self.repo[self.state.parentctxnode]
         return parentctx, [(self.node, tuple())]
 
 @action(["mess", "m"],
         _('edit commit message without changing commit content'),
         priority=True)
 class message(histeditaction):
     def commiteditor(self):
         return cmdutil.getcommiteditor(edit=True, editform='histedit.mess')
 
 def findoutgoing(ui, repo, remote=None, force=False, opts=None):
     """utility function to find the first outgoing changeset
 
     Used by initialization code"""
     if opts is None:
         opts = {}
     dest = ui.expandpath(remote or 'default-push', remote or 'default')
     dest, branches = hg.parseurl(dest, None)[:2]
     ui.status(_('comparing with %s\n') % util.hidepassword(dest))
 
     revs, checkout = hg.addbranchrevs(repo, repo, branches, None)
     other = hg.peer(repo, opts, dest)
 
     if revs:
         revs = [repo.lookup(rev) for rev in revs]
 
     outgoing = discovery.findcommonoutgoing(repo, other, revs, force=force)
     if not outgoing.missing:
         raise error.Abort(_('no outgoing ancestors'))
     roots = list(repo.revs("roots(%ln)", outgoing.missing))
     if len(roots) > 1:
         msg = _('there are ambiguous outgoing revisions')
         hint = _("see 'hg help histedit' for more detail")
         raise error.Abort(msg, hint=hint)
     return repo[roots[0]].node()
 
 # Curses Support
 try:
     import curses
-
-    # Curses requires setting the locale or it will default to the C
-    # locale. This sets the locale to the user's default system
-    # locale.
-    import locale
-    locale.setlocale(locale.LC_ALL, r'')
 except ImportError:
     curses = None
 
 KEY_LIST = ['pick', 'edit', 'fold', 'drop', 'mess', 'roll']
 ACTION_LABELS = {
     'fold': '^fold',
     'roll': '^roll',
 }
 
 COLOR_HELP, COLOR_SELECTED, COLOR_OK, COLOR_WARN, COLOR_CURRENT  = 1, 2, 3, 4, 5
 COLOR_DIFF_ADD_LINE, COLOR_DIFF_DEL_LINE, COLOR_DIFF_OFFSET = 6, 7, 8
 
 E_QUIT, E_HISTEDIT = 1, 2
 E_PAGEDOWN, E_PAGEUP, E_LINEUP, E_LINEDOWN, E_RESIZE = 3, 4, 5, 6, 7
 MODE_INIT, MODE_PATCH, MODE_RULES, MODE_HELP = 0, 1, 2, 3
 
 KEYTABLE = {
     'global': {
         'h':         'next-action',
         'KEY_RIGHT': 'next-action',
         'l':         'prev-action',
         'KEY_LEFT':  'prev-action',
         'q':         'quit',
         'c':         'histedit',
         'C':         'histedit',
         'v':         'showpatch',
         '?':         'help',
     },
     MODE_RULES: {
         'd':         'action-drop',
         'e':         'action-edit',
         'f':         'action-fold',
         'm':         'action-mess',
         'p':         'action-pick',
         'r':         'action-roll',
         ' ':         'select',
         'j':         'down',
         'k':         'up',
         'KEY_DOWN':  'down',
         'KEY_UP':    'up',
         'J':         'move-down',
         'K':         'move-up',
         'KEY_NPAGE': 'move-down',
         'KEY_PPAGE': 'move-up',
         '0':         'goto',  # Used for 0..9
     },
     MODE_PATCH: {
         ' ':         'page-down',
         'KEY_NPAGE': 'page-down',
         'KEY_PPAGE': 'page-up',
         'j':         'line-down',
         'k':         'line-up',
         'KEY_DOWN':  'line-down',
         'KEY_UP':    'line-up',
         'J':         'down',
         'K':         'up',
     },
     MODE_HELP: {
     },
 }
 
 def screen_size():
     return struct.unpack('hh', fcntl.ioctl(1, termios.TIOCGWINSZ, '    '))
 
 class histeditrule(object):
     def __init__(self, ctx, pos, action='pick'):
         self.ctx = ctx
         self.action = action
         self.origpos = pos
         self.pos = pos
         self.conflicts = []
 
     def __str__(self):
         # Some actions ('fold' and 'roll') combine a patch with a previous one.
         # Add a marker showing which patch they apply to, and also omit the
         # description for 'roll' (since it will get discarded). Example display:
         #
         #  #10 pick   316392:06a16c25c053   add option to skip tests
         #  #11 ^roll  316393:71313c964cc5
         #  #12 pick   316394:ab31f3973b0d   include mfbt for mozilla-config.h
         #  #13 ^fold  316395:14ce5803f4c3   fix warnings
         #
         # The carets point to the changeset being folded into ("roll this
         # changeset into the changeset above").
         action = ACTION_LABELS.get(self.action, self.action)
         h = self.ctx.hex()[0:12]
         r = self.ctx.rev()
         desc = self.ctx.description().splitlines()[0].strip()
         if self.action == 'roll':
             desc = ''
         return "#{0:<2} {1:<6} {2}:{3}   {4}".format(
                 self.origpos, action, r, h, desc)
 
     def checkconflicts(self, other):
         if other.pos > self.pos and other.origpos <= self.origpos:
             if set(other.ctx.files()) & set(self.ctx.files()) != set():
                 self.conflicts.append(other)
                 return self.conflicts
 
         if other in self.conflicts:
             self.conflicts.remove(other)
         return self.conflicts
 
 # ============ EVENTS ===============
 def movecursor(state, oldpos, newpos):
     '''Change the rule/changeset that the cursor is pointing to, regardless of
     current mode (you can switch between patches from the view patch window).'''
     state['pos'] = newpos
 
     mode, _ = state['mode']
     if mode == MODE_RULES:
         # Scroll through the list by updating the view for MODE_RULES, so that
         # even if we are not currently viewing the rules, switching back will
         # result in the cursor's rule being visible.
         modestate = state['modes'][MODE_RULES]
         if newpos < modestate['line_offset']:
             modestate['line_offset'] = newpos
         elif newpos > modestate['line_offset'] + state['page_height'] - 1:
             modestate['line_offset'] = newpos - state['page_height'] + 1
 
     # Reset the patch view region to the top of the new patch.
     state['modes'][MODE_PATCH]['line_offset'] = 0
 
 def changemode(state, mode):
     curmode, _ = state['mode']
     state['mode'] = (mode, curmode)
     if mode == MODE_PATCH:
         state['modes'][MODE_PATCH]['patchcontents'] = patchcontents(state)
 
 def makeselection(state, pos):
     state['selected'] = pos
 
 def swap(state, oldpos, newpos):
     """Swap two positions and calculate necessary conflicts in
     O(|newpos-oldpos|) time"""
 
     rules = state['rules']
     assert 0 <= oldpos < len(rules) and 0 <= newpos < len(rules)
 
     rules[oldpos], rules[newpos] = rules[newpos], rules[oldpos]
 
     # TODO: swap should not know about histeditrule's internals
     rules[newpos].pos = newpos
     rules[oldpos].pos = oldpos
 
     start = min(oldpos, newpos)
     end = max(oldpos, newpos)
     for r in pycompat.xrange(start, end + 1):
         rules[newpos].checkconflicts(rules[r])
         rules[oldpos].checkconflicts(rules[r])
 
     if state['selected']:
         makeselection(state, newpos)
 
 def changeaction(state, pos, action):
     """Change the action state on the given position to the new action"""
     rules = state['rules']
     assert 0 <= pos < len(rules)
     rules[pos].action = action
 
 def cycleaction(state, pos, next=False):
     """Changes the action state the next or the previous action from
     the action list"""
     rules = state['rules']
     assert 0 <= pos < len(rules)
     current = rules[pos].action
 
     assert current in KEY_LIST
 
     index = KEY_LIST.index(current)
     if next:
         index += 1
     else:
         index -= 1
     changeaction(state, pos, KEY_LIST[index % len(KEY_LIST)])
 
 def changeview(state, delta, unit):
     '''Change the region of whatever is being viewed (a patch or the list of
     changesets). 'delta' is an amount (+/- 1) and 'unit' is 'page' or 'line'.'''
     mode, _ = state['mode']
     if mode != MODE_PATCH:
         return
     mode_state = state['modes'][mode]
     num_lines = len(mode_state['patchcontents'])
     page_height = state['page_height']
     unit = page_height if unit == 'page' else 1
     num_pages = 1 + (num_lines - 1) / page_height
     max_offset = (num_pages - 1) * page_height
     newline = mode_state['line_offset'] + delta * unit
     mode_state['line_offset'] = max(0, min(max_offset, newline))
 
 def event(state, ch):
     """Change state based on the current character input
 
     This takes the current state and based on the current character input from
     the user we change the state.
     """
     selected = state['selected']
     oldpos = state['pos']
     rules = state['rules']
 
     if ch in (curses.KEY_RESIZE, "KEY_RESIZE"):
         return E_RESIZE
 
     lookup_ch = ch
     if '0' <= ch <= '9':
         lookup_ch = '0'
 
     curmode, prevmode = state['mode']
     action = KEYTABLE[curmode].get(lookup_ch, KEYTABLE['global'].get(lookup_ch))
     if action is None:
         return
     if action in ('down', 'move-down'):
         newpos = min(oldpos + 1, len(rules) - 1)
         movecursor(state, oldpos, newpos)
         if selected is not None or action == 'move-down':
             swap(state, oldpos, newpos)
     elif action in ('up', 'move-up'):
         newpos = max(0, oldpos - 1)
         movecursor(state, oldpos, newpos)
         if selected is not None or action == 'move-up':
             swap(state, oldpos, newpos)
     elif action == 'next-action':
         cycleaction(state, oldpos, next=True)
     elif action == 'prev-action':
         cycleaction(state, oldpos, next=False)
     elif action == 'select':
         selected = oldpos if selected is None else None
         makeselection(state, selected)
     elif action == 'goto' and int(ch) < len(rules) and len(rules) <= 10:
         newrule = next((r for r in rules if r.origpos == int(ch)))
         movecursor(state, oldpos, newrule.pos)
         if selected is not None:
             swap(state, oldpos, newrule.pos)
     elif action.startswith('action-'):
         changeaction(state, oldpos, action[7:])
     elif action == 'showpatch':
         changemode(state, MODE_PATCH if curmode != MODE_PATCH else prevmode)
     elif action == 'help':
         changemode(state, MODE_HELP if curmode != MODE_HELP else prevmode)
     elif action == 'quit':
         return E_QUIT
     elif action == 'histedit':
         return E_HISTEDIT
     elif action == 'page-down':
         return E_PAGEDOWN
     elif action == 'page-up':
         return E_PAGEUP
     elif action == 'line-down':
         return E_LINEDOWN
     elif action == 'line-up':
         return E_LINEUP
 
 def makecommands(rules):
     """Returns a list of commands consumable by histedit --commands based on
     our list of rules"""
     commands = []
     for rules in rules:
         commands.append("{0} {1}\n".format(rules.action, rules.ctx))
     return commands
 
 def addln(win, y, x, line, color=None):
     """Add a line to the given window left padding but 100% filled with
     whitespace characters, so that the color appears on the whole line"""
     maxy, maxx = win.getmaxyx()
     length = maxx - 1 - x
     line = ("{0:<%d}" % length).format(str(line).strip())[:length]
     if y < 0:
         y = maxy + y
     if x < 0:
         x = maxx + x
     if color:
         win.addstr(y, x, line, color)
     else:
         win.addstr(y, x, line)
 
 def _trunc_head(line, n):
     if len(line) <= n:
         return line
     return '> ' + line[-(n - 2):]
 def _trunc_tail(line, n):
     if len(line) <= n:
         return line
     return line[:n - 2] + ' >'
 
 def patchcontents(state):
     repo = state['repo']
     rule = state['rules'][state['pos']]
     displayer = logcmdutil.changesetdisplayer(repo.ui, repo, {
         "patch": True,  "template": "status"
     }, buffered=True)
     overrides = {('ui',  'verbose'): True}
     with repo.ui.configoverride(overrides, source='histedit'):
         displayer.show(rule.ctx)
         displayer.close()
     return displayer.hunk[rule.ctx.rev()].splitlines()
 
 def _chisteditmain(repo, rules, stdscr):
     try:
         curses.use_default_colors()
     except curses.error:
         pass
 
     # initialize color pattern
     curses.init_pair(COLOR_HELP, curses.COLOR_WHITE, curses.COLOR_BLUE)
     curses.init_pair(COLOR_SELECTED, curses.COLOR_BLACK, curses.COLOR_WHITE)
     curses.init_pair(COLOR_WARN, curses.COLOR_BLACK, curses.COLOR_YELLOW)
     curses.init_pair(COLOR_OK, curses.COLOR_BLACK, curses.COLOR_GREEN)
     curses.init_pair(COLOR_CURRENT, curses.COLOR_WHITE, curses.COLOR_MAGENTA)
     curses.init_pair(COLOR_DIFF_ADD_LINE, curses.COLOR_GREEN, -1)
     curses.init_pair(COLOR_DIFF_DEL_LINE, curses.COLOR_RED, -1)
     curses.init_pair(COLOR_DIFF_OFFSET, curses.COLOR_MAGENTA, -1)
 
     # don't display the cursor
     try:
         curses.curs_set(0)
     except curses.error:
         pass
 
     def rendercommit(win, state):
         """Renders the commit window that shows the log of the current selected
         commit"""
         pos = state['pos']
         rules = state['rules']
         rule = rules[pos]
 
         ctx = rule.ctx
         win.box()
 
         maxy, maxx = win.getmaxyx()
         length = maxx - 3
 
         line = "changeset: {0}:{1:<12}".format(ctx.rev(), ctx)
         win.addstr(1, 1, line[:length])
 
         line = "user:      {0}".format(ctx.user())
         win.addstr(2, 1, line[:length])
 
         bms = repo.nodebookmarks(ctx.node())
         line = "bookmark:  {0}".format(' '.join(bms))
         win.addstr(3, 1, line[:length])
 
         line = "summary:   {0}".format(ctx.description().splitlines()[0])
         win.addstr(4, 1, line[:length])
 
         line = "files:     "
         win.addstr(5, 1, line)
         fnx = 1 + len(line)
         fnmaxx = length - fnx + 1
         y = 5
         fnmaxn = maxy - (1 + y) - 1
         files = ctx.files()
         for i, line1 in enumerate(files):
             if len(files) > fnmaxn and i == fnmaxn - 1:
                 win.addstr(y, fnx, _trunc_tail(','.join(files[i:]), fnmaxx))
                 y = y + 1
                 break
             win.addstr(y, fnx, _trunc_head(line1, fnmaxx))
             y = y + 1
 
         conflicts = rule.conflicts
         if len(conflicts) > 0:
             conflictstr = ','.join(map(lambda r: str(r.ctx), conflicts))
             conflictstr = "changed files overlap with {0}".format(conflictstr)
         else:
             conflictstr = 'no overlap'
 
         win.addstr(y, 1, conflictstr[:length])
         win.noutrefresh()
 
     def helplines(mode):
         if mode == MODE_PATCH:
             help = """\
 ?: help, k/up: line up, j/down: line down, v: stop viewing patch
 pgup: prev page, space/pgdn: next page, c: commit, q: abort
 """
         else:
             help = """\
 ?: help, k/up: move up, j/down: move down, space: select, v: view patch
 d: drop, e: edit, f: fold, m: mess, p: pick, r: roll
 pgup/K: move patch up, pgdn/J: move patch down, c: commit, q: abort
 """
         return help.splitlines()
 
     def renderhelp(win, state):
         maxy, maxx = win.getmaxyx()
         mode, _ = state['mode']
         for y, line in enumerate(helplines(mode)):
             if y >= maxy:
                 break
             addln(win, y, 0, line, curses.color_pair(COLOR_HELP))
         win.noutrefresh()
 
     def renderrules(rulesscr, state):
         rules = state['rules']
         pos = state['pos']
         selected = state['selected']
         start = state['modes'][MODE_RULES]['line_offset']
 
         conflicts = [r.ctx for r in rules if r.conflicts]
         if len(conflicts) > 0:
             line = "potential conflict in %s" % ','.join(map(str, conflicts))
             addln(rulesscr, -1, 0, line, curses.color_pair(COLOR_WARN))
 
         for y, rule in enumerate(rules[start:]):
             if y >= state['page_height']:
                 break
             if len(rule.conflicts) > 0:
                 rulesscr.addstr(y, 0, " ", curses.color_pair(COLOR_WARN))
             else:
                 rulesscr.addstr(y, 0, " ", curses.COLOR_BLACK)
             if y + start == selected:
                 addln(rulesscr, y, 2, rule, curses.color_pair(COLOR_SELECTED))
             elif y + start == pos:
                 addln(rulesscr, y, 2, rule,
                       curses.color_pair(COLOR_CURRENT) | curses.A_BOLD)
             else:
                 addln(rulesscr, y, 2, rule)
         rulesscr.noutrefresh()
 
     def renderstring(win, state, output, diffcolors=False):
         maxy, maxx = win.getmaxyx()
         length = min(maxy - 1, len(output))
         for y in range(0, length):
             line = output[y]
             if diffcolors:
                 if line and line[0] == '+':
                     win.addstr(
                         y, 0, line, curses.color_pair(COLOR_DIFF_ADD_LINE))
                 elif line and line[0] == '-':
                     win.addstr(
                         y, 0, line, curses.color_pair(COLOR_DIFF_DEL_LINE))
                 elif line.startswith('@@ '):
                     win.addstr(
                         y, 0, line, curses.color_pair(COLOR_DIFF_OFFSET))
                 else:
                     win.addstr(y, 0, line)
             else:
                 win.addstr(y, 0, line)
         win.noutrefresh()
 
     def renderpatch(win, state):
         start = state['modes'][MODE_PATCH]['line_offset']
         content = state['modes'][MODE_PATCH]['patchcontents']
         renderstring(win, state, content[start:], diffcolors=True)
 
     def layout(mode):
         maxy, maxx = stdscr.getmaxyx()
         helplen = len(helplines(mode))
         return {
             'commit': (12, maxx),
             'help': (helplen, maxx),
             'main': (maxy - helplen - 12, maxx),
         }
 
     def drawvertwin(size, y, x):
         win = curses.newwin(size[0], size[1], y, x)
         y += size[0]
         return win, y, x
 
     state = {
         'pos': 0,
         'rules': rules,
         'selected': None,
         'mode': (MODE_INIT, MODE_INIT),
         'page_height': None,
         'modes': {
             MODE_RULES: {
                 'line_offset': 0,
             },
             MODE_PATCH: {
                 'line_offset': 0,
             }
         },
         'repo': repo,
     }
 
     # eventloop
     ch = None
     stdscr.clear()
     stdscr.refresh()
     while True:
         try:
             oldmode, _ = state['mode']
             if oldmode == MODE_INIT:
                 changemode(state, MODE_RULES)
             e = event(state, ch)
 
             if e == E_QUIT:
                 return False
             if e == E_HISTEDIT:
                 return state['rules']
             else:
                 if e == E_RESIZE:
                     size = screen_size()
                     if size != stdscr.getmaxyx():
                         curses.resizeterm(*size)
 
                 curmode, _ = state['mode']
                 sizes = layout(curmode)
                 if curmode != oldmode:
                     state['page_height'] = sizes['main'][0]
                     # Adjust the view to fit the current screen size.
                     movecursor(state, state['pos'], state['pos'])
 
                 # Pack the windows against the top, each pane spread across the
                 # full width of the screen.
                 y, x = (0, 0)
                 helpwin, y, x = drawvertwin(sizes['help'], y, x)
                 mainwin, y, x = drawvertwin(sizes['main'], y, x)
                 commitwin, y, x = drawvertwin(sizes['commit'], y, x)
 
                 if e in (E_PAGEDOWN, E_PAGEUP, E_LINEDOWN, E_LINEUP):
                     if e == E_PAGEDOWN:
                         changeview(state, +1, 'page')
                     elif e == E_PAGEUP:
                         changeview(state, -1, 'page')
                     elif e == E_LINEDOWN:
                         changeview(state, +1, 'line')
                     elif e == E_LINEUP:
                         changeview(state, -1, 'line')
 
                 # start rendering
                 commitwin.erase()
                 helpwin.erase()
                 mainwin.erase()
                 if curmode == MODE_PATCH:
                     renderpatch(mainwin, state)
                 elif curmode == MODE_HELP:
                     renderstring(mainwin, state, __doc__.strip().splitlines())
                 else:
                     renderrules(mainwin, state)
                     rendercommit(commitwin, state)
                 renderhelp(helpwin, state)
                 curses.doupdate()
                 # done rendering
                 ch = stdscr.getkey()
         except curses.error:
             pass
 
 def _chistedit(ui, repo, *freeargs, **opts):
     """interactively edit changeset history via a curses interface
 
     Provides a ncurses interface to histedit. Press ? in chistedit mode
     to see an extensive help. Requires python-curses to be installed."""
 
     if curses is None:
         raise error.Abort(_("Python curses library required"))
 
     # disable color
     ui._colormode = None
 
     try:
         keep = opts.get('keep')
         revs = opts.get('rev', [])[:]
         cmdutil.checkunfinished(repo)
         cmdutil.bailifchanged(repo)
 
         if os.path.exists(os.path.join(repo.path, 'histedit-state')):
             raise error.Abort(_('history edit already in progress, try '
                                '--continue or --abort'))
         revs.extend(freeargs)
         if not revs:
             defaultrev = destutil.desthistedit(ui, repo)
             if defaultrev is not None:
                 revs.append(defaultrev)
         if len(revs) != 1:
             raise error.Abort(
                 _('histedit requires exactly one ancestor revision'))
 
         rr = list(repo.set('roots(%ld)', scmutil.revrange(repo, revs)))
         if len(rr) != 1:
             raise error.Abort(_('The specified revisions must have '
                 'exactly one common root'))
         root = rr[0].node()
 
         topmost = repo.dirstate.p1()
         revs = between(repo, root, topmost, keep)
         if not revs:
             raise error.Abort(_('%s is not an ancestor of working directory') %
                              node.short(root))
 
         ctxs = []
         for i, r in enumerate(revs):
             ctxs.append(histeditrule(repo[r], i))
+        # Curses requires setting the locale or it will default to the C
+        # locale. This sets the locale to the user's default system
+        # locale.
+        locale.setlocale(locale.LC_ALL, r'')
         rc = curses.wrapper(functools.partial(_chisteditmain, repo, ctxs))
         curses.echo()
         curses.endwin()
         if rc is False:
             ui.write(_("histedit aborted\n"))
             return 0
         if type(rc) is list:
             ui.status(_("performing changes\n"))
             rules = makecommands(rc)
             filename = repo.vfs.join('chistedit')
             with open(filename, 'w+') as fp:
                 for r in rules:
                     fp.write(r)
             opts['commands'] = filename
             return _texthistedit(ui, repo, *freeargs, **opts)
     except KeyboardInterrupt:
         pass
     return -1
 
 @command('histedit',
     [('', 'commands', '',
       _('read history edits from the specified file'), _('FILE')),
      ('c', 'continue', False, _('continue an edit already in progress')),
      ('', 'edit-plan', False, _('edit remaining actions list')),
      ('k', 'keep', False,
       _("don't strip old nodes after edit is complete")),
      ('', 'abort', False, _('abort an edit in progress')),
      ('o', 'outgoing', False, _('changesets not found in destination')),
      ('f', 'force', False,
       _('force outgoing even for unrelated repositories')),
      ('r', 'rev', [], _('first revision to be edited'), _('REV'))] +
     cmdutil.formatteropts,
      _("[OPTIONS] ([ANCESTOR] | --outgoing [URL])"),
     helpcategory=command.CATEGORY_CHANGE_MANAGEMENT)
 def histedit(ui, repo, *freeargs, **opts):
     """interactively edit changeset history
 
     This command lets you edit a linear series of changesets (up to
     and including the working directory, which should be clean).
     You can:
 
     - `pick` to [re]order a changeset
 
     - `drop` to omit changeset
 
     - `mess` to reword the changeset commit message
 
     - `fold` to combine it with the preceding changeset (using the later date)
 
     - `roll` like fold, but discarding this commit's description and date
 
     - `edit` to edit this changeset (preserving date)
 
     - `base` to checkout changeset and apply further changesets from there
 
     There are a number of ways to select the root changeset:
 
     - Specify ANCESTOR directly
 
     - Use --outgoing -- it will be the first linear changeset not
       included in destination. (See :hg:`help config.paths.default-push`)
 
     - Otherwise, the value from the "histedit.defaultrev" config option
       is used as a revset to select the base revision when ANCESTOR is not
       specified. The first revision returned by the revset is used. By
       default, this selects the editable history that is unique to the
       ancestry of the working directory.
 
     .. container:: verbose
 
        If you use --outgoing, this command will abort if there are ambiguous
        outgoing revisions. For example, if there are multiple branches
        containing outgoing revisions.
 
        Use "min(outgoing() and ::.)" or similar revset specification
        instead of --outgoing to specify edit target revision exactly in
        such ambiguous situation. See :hg:`help revsets` for detail about
        selecting revisions.
 
     .. container:: verbose
 
        Examples:
 
          - A number of changes have been made.
            Revision 3 is no longer needed.
 
            Start history editing from revision 3::
 
              hg histedit -r 3
 
            An editor opens, containing the list of revisions,
            with specific actions specified::
 
              pick 5339bf82f0ca 3 Zworgle the foobar
              pick 8ef592ce7cc4 4 Bedazzle the zerlog
              pick 0a9639fcda9d 5 Morgify the cromulancy
 
            Additional information about the possible actions
            to take appears below the list of revisions.
 
            To remove revision 3 from the history,
            its action (at the beginning of the relevant line)
            is changed to 'drop'::
 
              drop 5339bf82f0ca 3 Zworgle the foobar
              pick 8ef592ce7cc4 4 Bedazzle the zerlog
              pick 0a9639fcda9d 5 Morgify the cromulancy
 
          - A number of changes have been made.
            Revision 2 and 4 need to be swapped.
 
            Start history editing from revision 2::
 
              hg histedit -r 2
 
            An editor opens, containing the list of revisions,
            with specific actions specified::
 
              pick 252a1af424ad 2 Blorb a morgwazzle
              pick 5339bf82f0ca 3 Zworgle the foobar
              pick 8ef592ce7cc4 4 Bedazzle the zerlog
 
            To swap revision 2 and 4, its lines are swapped
            in the editor::
 
              pick 8ef592ce7cc4 4 Bedazzle the zerlog
              pick 5339bf82f0ca 3 Zworgle the foobar
              pick 252a1af424ad 2 Blorb a morgwazzle
 
     Returns 0 on success, 1 if user intervention is required (not only
     for intentional "edit" command, but also for resolving unexpected
     conflicts).
     """
     # kludge: _chistedit only works for starting an edit, not aborting
     # or continuing, so fall back to regular _texthistedit for those
     # operations.
     if ui.interface('histedit') == 'curses' and  _getgoal(
             pycompat.byteskwargs(opts)) == goalnew:
         return _chistedit(ui, repo, *freeargs, **opts)
     return _texthistedit(ui, repo, *freeargs, **opts)
 
 def _texthistedit(ui, repo, *freeargs, **opts):
     state = histeditstate(repo)
     with repo.wlock() as wlock, repo.lock() as lock:
         state.wlock = wlock
         state.lock = lock
         _histedit(ui, repo, state, *freeargs, **opts)
 
 goalcontinue = 'continue'
 goalabort = 'abort'
 goaleditplan = 'edit-plan'
 goalnew = 'new'
 
 def _getgoal(opts):
     if opts.get(b'continue'):
         return goalcontinue
     if opts.get(b'abort'):
         return goalabort
     if opts.get(b'edit_plan'):
         return goaleditplan
     return goalnew
 
 def _readfile(ui, path):
     if path == '-':
         with ui.timeblockedsection('histedit'):
             return ui.fin.read()
     else:
         with open(path, 'rb') as f:
             return f.read()
 
 def _validateargs(ui, repo, state, freeargs, opts, goal, rules, revs):
     # TODO only abort if we try to histedit mq patches, not just
     # blanket if mq patches are applied somewhere
     mq = getattr(repo, 'mq', None)
     if mq and mq.applied:
         raise error.Abort(_('source has mq patches applied'))
 
     # basic argument incompatibility processing
     outg = opts.get('outgoing')
     editplan = opts.get('edit_plan')
     abort = opts.get('abort')
     force = opts.get('force')
     if force and not outg:
         raise error.Abort(_('--force only allowed with --outgoing'))
     if goal == 'continue':
         if any((outg, abort, revs, freeargs, rules, editplan)):
             raise error.Abort(_('no arguments allowed with --continue'))
     elif goal == 'abort':
         if any((outg, revs, freeargs, rules, editplan)):
             raise error.Abort(_('no arguments allowed with --abort'))
     elif goal == 'edit-plan':
         if any((outg, revs, freeargs)):
             raise error.Abort(_('only --commands argument allowed with '
                                '--edit-plan'))
     else:
         if state.inprogress():
             raise error.Abort(_('history edit already in progress, try '
                                '--continue or --abort'))
         if outg:
             if revs:
                 raise error.Abort(_('no revisions allowed with --outgoing'))
             if len(freeargs) > 1:
                 raise error.Abort(
                     _('only one repo argument allowed with --outgoing'))
         else:
             revs.extend(freeargs)
             if len(revs) == 0:
                 defaultrev = destutil.desthistedit(ui, repo)
                 if defaultrev is not None:
                     revs.append(defaultrev)
 
             if len(revs) != 1:
                 raise error.Abort(
                     _('histedit requires exactly one ancestor revision'))
 
 def _histedit(ui, repo, state, *freeargs, **opts):
     opts = pycompat.byteskwargs(opts)
     fm = ui.formatter('histedit', opts)
     fm.startitem()
     goal = _getgoal(opts)
     revs = opts.get('rev', [])
     nobackup = not ui.configbool('rewrite', 'backup-bundle')
     rules = opts.get('commands', '')
     state.keep = opts.get('keep', False)
 
     _validateargs(ui, repo, state, freeargs, opts, goal, rules, revs)
 
     hastags = False
     if revs:
         revs = scmutil.revrange(repo, revs)
         ctxs = [repo[rev] for rev in revs]
         for ctx in ctxs:
             tags = [tag for tag in ctx.tags() if tag != 'tip']
             if not hastags:
                 hastags = len(tags)
     if hastags:
         if ui.promptchoice(_('warning: tags associated with the given'
                              ' changeset will be lost after histedit.\n'
                              'do you want to continue (yN)? $$ &Yes $$ &No'),
                            default=1):
             raise error.Abort(_('histedit cancelled\n'))
     # rebuild state
     if goal == goalcontinue:
         state.read()
         state = bootstrapcontinue(ui, state, opts)
     elif goal == goaleditplan:
         _edithisteditplan(ui, repo, state, rules)
         return
     elif goal == goalabort:
         _aborthistedit(ui, repo, state, nobackup=nobackup)
         return
     else:
         # goal == goalnew
         _newhistedit(ui, repo, state, revs, freeargs, opts)
 
     _continuehistedit(ui, repo, state)
     _finishhistedit(ui, repo, state, fm)
     fm.end()
 
 def _continuehistedit(ui, repo, state):
     """This function runs after either:
     - bootstrapcontinue (if the goal is 'continue')
     - _newhistedit (if the goal is 'new')
     """
     # preprocess rules so that we can hide inner folds from the user
     # and only show one editor
     actions = state.actions[:]
     for idx, (action, nextact) in enumerate(
             zip(actions, actions[1:] + [None])):
         if action.verb == 'fold' and nextact and nextact.verb == 'fold':
             state.actions[idx].__class__ = _multifold
 
     # Force an initial state file write, so the user can run --abort/continue
     # even if there's an exception before the first transaction serialize.
     state.write()
 
     tr = None
     # Don't use singletransaction by default since it rolls the entire
     # transaction back if an unexpected exception happens (like a
     # pretxncommit hook throws, or the user aborts the commit msg editor).
     if ui.configbool("histedit", "singletransaction"):
         # Don't use a 'with' for the transaction, since actions may close
         # and reopen a transaction. For example, if the action executes an
         # external process it may choose to commit the transaction first.
         tr = repo.transaction('histedit')
     progress = ui.makeprogress(_("editing"), unit=_('changes'),
                                total=len(state.actions))
     with progress, util.acceptintervention(tr):
         while state.actions:
             state.write(tr=tr)
             actobj = state.actions[0]
             progress.increment(item=actobj.torule())
             ui.debug('histedit: processing %s %s\n' % (actobj.verb,
                                                        actobj.torule()))
             parentctx, replacement_ = actobj.run()
             state.parentctxnode = parentctx.node()
             state.replacements.extend(replacement_)
             state.actions.pop(0)
 
     state.write()
 
 def _finishhistedit(ui, repo, state, fm):
     """This action runs when histedit is finishing its session"""
     hg.updaterepo(repo, state.parentctxnode, overwrite=False)
 
     mapping, tmpnodes, created, ntm = processreplacement(state)
     if mapping:
         for prec, succs in mapping.iteritems():
             if not succs:
                 ui.debug('histedit: %s is dropped\n' % node.short(prec))
             else:
                 ui.debug('histedit: %s is replaced by %s\n' % (
                     node.short(prec), node.short(succs[0])))
                 if len(succs) > 1:
                     m = 'histedit:                            %s'
                     for n in succs[1:]:
                         ui.debug(m % node.short(n))
 
     if not state.keep:
         if mapping:
             movetopmostbookmarks(repo, state.topmost, ntm)
             # TODO update mq state
     else:
         mapping = {}
 
     for n in tmpnodes:
         if n in repo:
             mapping[n] = ()
 
     # remove entries about unknown nodes
     nodemap = repo.unfiltered().changelog.nodemap
     mapping = {k: v for k, v in mapping.items()
                if k in nodemap and all(n in nodemap for n in v)}
     scmutil.cleanupnodes(repo, mapping, 'histedit')
     hf = fm.hexfunc
     fl = fm.formatlist
     fd = fm.formatdict
     nodechanges = fd({hf(oldn): fl([hf(n) for n in newn], name='node')
                       for oldn, newn in mapping.iteritems()},
                      key="oldnode", value="newnodes")
     fm.data(nodechanges=nodechanges)
 
     state.clear()
     if os.path.exists(repo.sjoin('undo')):
         os.unlink(repo.sjoin('undo'))
     if repo.vfs.exists('histedit-last-edit.txt'):
         repo.vfs.unlink('histedit-last-edit.txt')
 
 def _aborthistedit(ui, repo, state, nobackup=False):
     try:
         state.read()
         __, leafs, tmpnodes, __ = processreplacement(state)
         ui.debug('restore wc to old parent %s\n'
                 % node.short(state.topmost))
 
         # Recover our old commits if necessary
         if not state.topmost in repo and state.backupfile:
             backupfile = repo.vfs.join(state.backupfile)
             f = hg.openpath(ui, backupfile)
             gen = exchange.readbundle(ui, f, backupfile)
             with repo.transaction('histedit.abort') as tr:
                 bundle2.applybundle(repo, gen, tr, source='histedit',
                                     url='bundle:' + backupfile)
 
             os.remove(backupfile)
 
         # check whether we should update away
         if repo.unfiltered().revs('parents() and (%n  or %ln::)',
                                 state.parentctxnode, leafs | tmpnodes):
             hg.clean(repo, state.topmost, show_stats=True, quietempty=True)
         cleanupnode(ui, repo, tmpnodes, nobackup=nobackup)
         cleanupnode(ui, repo, leafs, nobackup=nobackup)
     except Exception:
         if state.inprogress():
             ui.warn(_('warning: encountered an exception during histedit '
                 '--abort; the repository may not have been completely '
                 'cleaned up\n'))
         raise
     finally:
             state.clear()
 
 def hgaborthistedit(ui, repo):
     state = histeditstate(repo)
     nobackup = not ui.configbool('rewrite', 'backup-bundle')
     with repo.wlock() as wlock, repo.lock() as lock:
         state.wlock = wlock
         state.lock = lock
         _aborthistedit(ui, repo, state, nobackup=nobackup)
 
 def _edithisteditplan(ui, repo, state, rules):
     state.read()
     if not rules:
         comment = geteditcomment(ui,
                                  node.short(state.parentctxnode),
                                  node.short(state.topmost))
         rules = ruleeditor(repo, ui, state.actions, comment)
     else:
         rules = _readfile(ui, rules)
     actions = parserules(rules, state)
     ctxs = [repo[act.node]
             for act in state.actions if act.node]
     warnverifyactions(ui, repo, actions, state, ctxs)
     state.actions = actions
     state.write()
 
 def _newhistedit(ui, repo, state, revs, freeargs, opts):
     outg = opts.get('outgoing')
     rules = opts.get('commands', '')
     force = opts.get('force')
 
     cmdutil.checkunfinished(repo)
     cmdutil.bailifchanged(repo)
 
     topmost = repo.dirstate.p1()
     if outg:
         if freeargs:
             remote = freeargs[0]
         else:
             remote = None
         root = findoutgoing(ui, repo, remote, force, opts)
     else:
         rr = list(repo.set('roots(%ld)', scmutil.revrange(repo, revs)))
         if len(rr) != 1:
             raise error.Abort(_('The specified revisions must have '
                 'exactly one common root'))
         root = rr[0].node()
 
     revs = between(repo, root, topmost, state.keep)
     if not revs:
         raise error.Abort(_('%s is not an ancestor of working directory') %
                          node.short(root))
 
     ctxs = [repo[r] for r in revs]
     if not rules:
         comment = geteditcomment(ui, node.short(root), node.short(topmost))
         actions = [pick(state, r) for r in revs]
         rules = ruleeditor(repo, ui, actions, comment)
     else:
         rules = _readfile(ui, rules)
     actions = parserules(rules, state)
     warnverifyactions(ui, repo, actions, state, ctxs)
 
     parentctxnode = repo[root].p1().node()
 
     state.parentctxnode = parentctxnode
     state.actions = actions
     state.topmost = topmost
     state.replacements = []
 
     ui.log("histedit", "%d actions to histedit\n", len(actions),
            histedit_num_actions=len(actions))
 
     # Create a backup so we can always abort completely.
     backupfile = None
     if not obsolete.isenabled(repo, obsolete.createmarkersopt):
         backupfile = repair.backupbundle(repo, [parentctxnode],
                                          [topmost], root, 'histedit')
     state.backupfile = backupfile
 
 def _getsummary(ctx):
     # a common pattern is to extract the summary but default to the empty
     # string
     summary = ctx.description() or ''
     if summary:
         summary = summary.splitlines()[0]
     return summary
 
 def bootstrapcontinue(ui, state, opts):
     repo = state.repo
 
     ms = mergemod.mergestate.read(repo)
     mergeutil.checkunresolved(ms)
 
     if state.actions:
         actobj = state.actions.pop(0)
 
         if _isdirtywc(repo):
             actobj.continuedirty()
             if _isdirtywc(repo):
                 abortdirty()
 
         parentctx, replacements = actobj.continueclean()
 
         state.parentctxnode = parentctx.node()
         state.replacements.extend(replacements)
 
     return state
 
 def between(repo, old, new, keep):
     """select and validate the set of revision to edit
 
     When keep is false, the specified set can't have children."""
     revs = repo.revs('%n::%n', old, new)
     if revs and not keep:
         if (not obsolete.isenabled(repo, obsolete.allowunstableopt) and
             repo.revs('(%ld::) - (%ld)', revs, revs)):
             raise error.Abort(_('can only histedit a changeset together '
                                 'with all its descendants'))
         if repo.revs('(%ld) and merge()', revs):
             raise error.Abort(_('cannot edit history that contains merges'))
         root = repo[revs.first()]  # list is already sorted by repo.revs()
         if not root.mutable():
             raise error.Abort(_('cannot edit public changeset: %s') % root,
                              hint=_("see 'hg help phases' for details"))
     return pycompat.maplist(repo.changelog.node, revs)
 
 def ruleeditor(repo, ui, actions, editcomment=""):
     """open an editor to edit rules
 
     rules are in the format [ [act, ctx], ...] like in state.rules
     """
     if repo.ui.configbool("experimental", "histedit.autoverb"):
         newact = util.sortdict()
         for act in actions:
             ctx = repo[act.node]
             summary = _getsummary(ctx)
             fword = summary.split(' ', 1)[0].lower()
             added = False
 
             # if it doesn't end with the special character '!' just skip this
             if fword.endswith('!'):
                 fword = fword[:-1]
                 if fword in primaryactions | secondaryactions | tertiaryactions:
                     act.verb = fword
                     # get the target summary
                     tsum = summary[len(fword) + 1:].lstrip()
                     # safe but slow: reverse iterate over the actions so we
                     # don't clash on two commits having the same summary
                     for na, l in reversed(list(newact.iteritems())):
                         actx = repo[na.node]
                         asum = _getsummary(actx)
                         if asum == tsum:
                             added = True
                             l.append(act)
                             break
 
             if not added:
                 newact[act] = []
 
         # copy over and flatten the new list
         actions = []
         for na, l in newact.iteritems():
             actions.append(na)
             actions += l
 
     rules = '\n'.join([act.torule() for act in actions])
     rules += '\n\n'
     rules += editcomment
     rules = ui.edit(rules, ui.username(), {'prefix': 'histedit'},
                     repopath=repo.path, action='histedit')
 
     # Save edit rules in .hg/histedit-last-edit.txt in case
     # the user needs to ask for help after something
     # surprising happens.
     with repo.vfs('histedit-last-edit.txt', 'wb') as f:
         f.write(rules)
 
     return rules
 
 def parserules(rules, state):
     """Read the histedit rules string and return list of action objects """
     rules = [l for l in (r.strip() for r in rules.splitlines())
                 if l and not l.startswith('#')]
     actions = []
     for r in rules:
         if ' ' not in r:
             raise error.ParseError(_('malformed line "%s"') % r)
         verb, rest = r.split(' ', 1)
 
         if verb not in actiontable:
             raise error.ParseError(_('unknown action "%s"') % verb)
 
         action = actiontable[verb].fromrule(state, rest)
         actions.append(action)
     return actions
 
 def warnverifyactions(ui, repo, actions, state, ctxs):
     try:
         verifyactions(actions, state, ctxs)
     except error.ParseError:
         if repo.vfs.exists('histedit-last-edit.txt'):
             ui.warn(_('warning: histedit rules saved '
                       'to: .hg/histedit-last-edit.txt\n'))
         raise
 
 def verifyactions(actions, state, ctxs):
     """Verify that there exists exactly one action per given changeset and
     other constraints.
 
     Will abort if there are to many or too few rules, a malformed rule,
     or a rule on a changeset outside of the user-given range.
     """
     expected = set(c.node() for c in ctxs)
     seen = set()
     prev = None
 
     if actions and actions[0].verb in ['roll', 'fold']:
         raise error.ParseError(_('first changeset cannot use verb "%s"') %
                                actions[0].verb)
 
     for action in actions:
         action.verify(prev, expected, seen)
         prev = action
         if action.node is not None:
             seen.add(action.node)
     missing = sorted(expected - seen)  # sort to stabilize output
 
     if state.repo.ui.configbool('histedit', 'dropmissing'):
         if len(actions) == 0:
             raise error.ParseError(_('no rules provided'),
                     hint=_('use strip extension to remove commits'))
 
         drops = [drop(state, n) for n in missing]
         # put the in the beginning so they execute immediately and
         # don't show in the edit-plan in the future
         actions[:0] = drops
     elif missing:
         raise error.ParseError(_('missing rules for changeset %s') %
                 node.short(missing[0]),
                 hint=_('use "drop %s" to discard, see also: '
                        "'hg help -e histedit.config'")
                        % node.short(missing[0]))
 
 def adjustreplacementsfrommarkers(repo, oldreplacements):
     """Adjust replacements from obsolescence markers
 
     Replacements structure is originally generated based on
     histedit's state and does not account for changes that are
     not recorded there. This function fixes that by adding
     data read from obsolescence markers"""
     if not obsolete.isenabled(repo, obsolete.createmarkersopt):
         return oldreplacements
 
     unfi = repo.unfiltered()
     nm = unfi.changelog.nodemap
     obsstore = repo.obsstore
     newreplacements = list(oldreplacements)
     oldsuccs = [r[1] for r in oldreplacements]
     # successors that have already been added to succstocheck once
     seensuccs = set().union(*oldsuccs) # create a set from an iterable of tuples
     succstocheck = list(seensuccs)
     while succstocheck:
         n = succstocheck.pop()
         missing = nm.get(n) is None
         markers = obsstore.successors.get(n, ())
         if missing and not markers:
             # dead end, mark it as such
             newreplacements.append((n, ()))
         for marker in markers:
             nsuccs = marker[1]
             newreplacements.append((n, nsuccs))
             for nsucc in nsuccs:
                 if nsucc not in seensuccs:
                     seensuccs.add(nsucc)
                     succstocheck.append(nsucc)
 
     return newreplacements
 
 def processreplacement(state):
     """process the list of replacements to return
 
     1) the final mapping between original and created nodes
     2) the list of temporary node created by histedit
     3) the list of new commit created by histedit"""
     replacements = adjustreplacementsfrommarkers(state.repo, state.replacements)
     allsuccs = set()
     replaced = set()
     fullmapping = {}
     # initialize basic set
     # fullmapping records all operations recorded in replacement
     for rep in replacements:
         allsuccs.update(rep[1])
         replaced.add(rep[0])
         fullmapping.setdefault(rep[0], set()).update(rep[1])
     new = allsuccs - replaced
     tmpnodes = allsuccs & replaced
     # Reduce content fullmapping into direct relation between original nodes
     # and final node created during history edition
     # Dropped changeset are replaced by an empty list
     toproceed = set(fullmapping)
     final = {}
     while toproceed:
         for x in list(toproceed):
             succs = fullmapping[x]
             for s in list(succs):
                 if s in toproceed:
                     # non final node with unknown closure
                     # We can't process this now
                     break
                 elif s in final:
                     # non final node, replace with closure
                     succs.remove(s)
                     succs.update(final[s])
             else:
                 final[x] = succs
                 toproceed.remove(x)
     # remove tmpnodes from final mapping
     for n in tmpnodes:
         del final[n]
     # we expect all changes involved in final to exist in the repo
     # turn `final` into list (topologically sorted)
     nm = state.repo.changelog.nodemap
     for prec, succs in final.items():
         final[prec] = sorted(succs, key=nm.get)
 
     # computed topmost element (necessary for bookmark)
     if new:
         newtopmost = sorted(new, key=state.repo.changelog.rev)[-1]
     elif not final:
         # Nothing rewritten at all. we won't need `newtopmost`
         # It is the same as `oldtopmost` and `processreplacement` know it
         newtopmost = None
     else:
         # every body died. The newtopmost is the parent of the root.
         r = state.repo.changelog.rev
         newtopmost = state.repo[sorted(final, key=r)[0]].p1().node()
 
     return final, tmpnodes, new, newtopmost
 
 def movetopmostbookmarks(repo, oldtopmost, newtopmost):
     """Move bookmark from oldtopmost to newly created topmost
 
     This is arguably a feature and we may only want that for the active
     bookmark. But the behavior is kept compatible with the old version for now.
     """
     if not oldtopmost or not newtopmost:
         return
     oldbmarks = repo.nodebookmarks(oldtopmost)
     if oldbmarks:
         with repo.lock(), repo.transaction('histedit') as tr:
             marks = repo._bookmarks
             changes = []
             for name in oldbmarks:
                 changes.append((name, newtopmost))
             marks.applychanges(repo, tr, changes)
 
 def cleanupnode(ui, repo, nodes, nobackup=False):
     """strip a group of nodes from the repository
 
     The set of node to strip may contains unknown nodes."""
     with repo.lock():
         # do not let filtering get in the way of the cleanse
         # we should probably get rid of obsolescence marker created during the
         # histedit, but we currently do not have such information.
         repo = repo.unfiltered()
         # Find all nodes that need to be stripped
         # (we use %lr instead of %ln to silently ignore unknown items)
         nm = repo.changelog.nodemap
         nodes = sorted(n for n in nodes if n in nm)
         roots = [c.node() for c in repo.set("roots(%ln)", nodes)]
         if roots:
             backup = not nobackup
             repair.strip(ui, repo, roots, backup=backup)
 
 def stripwrapper(orig, ui, repo, nodelist, *args, **kwargs):
     if isinstance(nodelist, str):
         nodelist = [nodelist]
     state = histeditstate(repo)
     if state.inprogress():
         state.read()
         histedit_nodes = {action.node for action
                           in state.actions if action.node}
         common_nodes = histedit_nodes & set(nodelist)
         if common_nodes:
             raise error.Abort(_("histedit in progress, can't strip %s")
                              % ', '.join(node.short(x) for x in common_nodes))
     return orig(ui, repo, nodelist, *args, **kwargs)
 
 extensions.wrapfunction(repair, 'strip', stripwrapper)
 
 def summaryhook(ui, repo):
     state = histeditstate(repo)
     if not state.inprogress():
         return
     state.read()
     if state.actions:
         # i18n: column positioning for "hg summary"
         ui.write(_('hist:   %s (histedit --continue)\n') %
                  (ui.label(_('%d remaining'), 'histedit.remaining') %
                   len(state.actions)))
 
 def extsetup(ui):
     cmdutil.summaryhooks.add('histedit', summaryhook)
     statemod.addunfinished('histedit', fname='histedit-state', allowcommit=True,
                             continueflag=True, abortfunc=hgaborthistedit)
-

mercurial/crecord.py

@@ -1,1916 +1,1915 b''
 # stuff related specifically to patch manipulation / parsing
 #
 # Copyright 2008 Mark Edgington <[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.
 #
 # This code is based on the Mark Edgington's crecord extension.
 # (Itself based on Bryan O'Sullivan's record extension.)
 
 from __future__ import absolute_import
 
 import locale
 import os
 import re
 import signal
 
 from .i18n import _
 from . import (
     encoding,
     error,
     patch as patchmod,
     pycompat,
     scmutil,
     util,
 )
 from .utils import (
     stringutil,
 )
 stringio = util.stringio
 
-# This is required for ncurses to display non-ASCII characters in default user
-# locale encoding correctly.  --immerrr
-locale.setlocale(locale.LC_ALL, r'')
-
 # patch comments based on the git one
 diffhelptext = _("""# To remove '-' lines, make them ' ' lines (context).
 # To remove '+' lines, delete them.
 # Lines starting with # will be removed from the patch.
 """)
 
 hunkhelptext = _("""#
 # If the patch applies cleanly, the edited hunk will immediately be
 # added to the record list. If it does not apply cleanly, a rejects file
 # will be generated. You can use that when you try again. If all lines
 # of the hunk are removed, then the edit is aborted and the hunk is left
 # unchanged.
 """)
 
 patchhelptext = _("""#
 # If the patch applies cleanly, the edited patch will immediately
 # be finalised. If it does not apply cleanly, rejects files will be
 # generated. You can use those when you try again.
 """)
 
 try:
     import curses
     curses.error
 except ImportError:
     # I have no idea if wcurses works with crecord...
     try:
         import wcurses as curses
         curses.error
     except ImportError:
         # wcurses is not shipped on Windows by default, or python is not
         # compiled with curses
         curses = False
 
 class fallbackerror(error.Abort):
     """Error that indicates the client should try to fallback to text mode."""
     # Inherits from error.Abort so that existing behavior is preserved if the
     # calling code does not know how to fallback.
 
 def checkcurses(ui):
     """Return True if the user wants to use curses
 
     This method returns True if curses is found (and that python is built with
     it) and that the user has the correct flag for the ui.
     """
     return curses and ui.interface("chunkselector") == "curses"
 
 class patchnode(object):
     """abstract class for patch graph nodes
     (i.e. patchroot, header, hunk, hunkline)
     """
 
     def firstchild(self):
         raise NotImplementedError("method must be implemented by subclass")
 
     def lastchild(self):
         raise NotImplementedError("method must be implemented by subclass")
 
     def allchildren(self):
         "Return a list of all of the direct children of this node"
         raise NotImplementedError("method must be implemented by subclass")
 
     def nextsibling(self):
         """
         Return the closest next item of the same type where there are no items
         of different types between the current item and this closest item.
         If no such item exists, return None.
         """
         raise NotImplementedError("method must be implemented by subclass")
 
     def prevsibling(self):
         """
         Return the closest previous item of the same type where there are no
         items of different types between the current item and this closest item.
         If no such item exists, return None.
         """
         raise NotImplementedError("method must be implemented by subclass")
 
     def parentitem(self):
         raise NotImplementedError("method must be implemented by subclass")
 
     def nextitem(self, skipfolded=True):
         """
         Try to return the next item closest to this item, regardless of item's
         type (header, hunk, or hunkline).
 
         If skipfolded == True, and the current item is folded, then the child
         items that are hidden due to folding will be skipped when determining
         the next item.
 
         If it is not possible to get the next item, return None.
         """
         try:
             itemfolded = self.folded
         except AttributeError:
             itemfolded = False
         if skipfolded and itemfolded:
             nextitem = self.nextsibling()
             if nextitem is None:
                 try:
                     nextitem = self.parentitem().nextsibling()
                 except AttributeError:
                     nextitem = None
             return nextitem
         else:
             # try child
             item = self.firstchild()
             if item is not None:
                 return item
 
             # else try next sibling
             item = self.nextsibling()
             if item is not None:
                 return item
 
             try:
                 # else try parent's next sibling
                 item = self.parentitem().nextsibling()
                 if item is not None:
                     return item
 
                 # else return grandparent's next sibling (or None)
                 return self.parentitem().parentitem().nextsibling()
 
             except AttributeError: # parent and/or grandparent was None
                 return None
 
     def previtem(self):
         """
         Try to return the previous item closest to this item, regardless of
         item's type (header, hunk, or hunkline).
 
         If it is not possible to get the previous item, return None.
         """
         # try previous sibling's last child's last child,
         # else try previous sibling's last child, else try previous sibling
         prevsibling = self.prevsibling()
         if prevsibling is not None:
             prevsiblinglastchild = prevsibling.lastchild()
             if ((prevsiblinglastchild is not None) and
                 not prevsibling.folded):
                 prevsiblinglclc = prevsiblinglastchild.lastchild()
                 if ((prevsiblinglclc is not None) and
                     not prevsiblinglastchild.folded):
                     return prevsiblinglclc
                 else:
                     return prevsiblinglastchild
             else:
                 return prevsibling
 
         # try parent (or None)
         return self.parentitem()
 
 class patch(patchnode, list): # todo: rename patchroot
     """
     list of header objects representing the patch.
     """
     def __init__(self, headerlist):
         self.extend(headerlist)
         # add parent patch object reference to each header
         for header in self:
             header.patch = self
 
 class uiheader(patchnode):
     """patch header
 
     xxx shouldn't we move this to mercurial/patch.py ?
     """
 
     def __init__(self, header):
         self.nonuiheader = header
         # flag to indicate whether to apply this chunk
         self.applied = True
         # flag which only affects the status display indicating if a node's
         # children are partially applied (i.e. some applied, some not).
         self.partial = False
 
         # flag to indicate whether to display as folded/unfolded to user
         self.folded = True
 
         # list of all headers in patch
         self.patch = None
 
         # flag is False if this header was ever unfolded from initial state
         self.neverunfolded = True
         self.hunks = [uihunk(h, self) for h in self.hunks]
 
     def prettystr(self):
         x = stringio()
         self.pretty(x)
         return x.getvalue()
 
     def nextsibling(self):
         numheadersinpatch = len(self.patch)
         indexofthisheader = self.patch.index(self)
 
         if indexofthisheader < numheadersinpatch - 1:
             nextheader = self.patch[indexofthisheader + 1]
             return nextheader
         else:
             return None
 
     def prevsibling(self):
         indexofthisheader = self.patch.index(self)
         if indexofthisheader > 0:
             previousheader = self.patch[indexofthisheader - 1]
             return previousheader
         else:
             return None
 
     def parentitem(self):
         """
         there is no 'real' parent item of a header that can be selected,
         so return None.
         """
         return None
 
     def firstchild(self):
         "return the first child of this item, if one exists.  otherwise None."
         if len(self.hunks) > 0:
             return self.hunks[0]
         else:
             return None
 
     def lastchild(self):
         "return the last child of this item, if one exists.  otherwise None."
         if len(self.hunks) > 0:
             return self.hunks[-1]
         else:
             return None
 
     def allchildren(self):
         "return a list of all of the direct children of this node"
         return self.hunks
 
     def __getattr__(self, name):
         return getattr(self.nonuiheader, name)
 
 class uihunkline(patchnode):
     "represents a changed line in a hunk"
     def __init__(self, linetext, hunk):
         self.linetext = linetext
         self.applied = True
         # the parent hunk to which this line belongs
         self.hunk = hunk
         # folding lines currently is not used/needed, but this flag is needed
         # in the previtem method.
         self.folded = False
 
     def prettystr(self):
         return self.linetext
 
     def nextsibling(self):
         numlinesinhunk = len(self.hunk.changedlines)
         indexofthisline = self.hunk.changedlines.index(self)
 
         if (indexofthisline < numlinesinhunk - 1):
             nextline = self.hunk.changedlines[indexofthisline + 1]
             return nextline
         else:
             return None
 
     def prevsibling(self):
         indexofthisline = self.hunk.changedlines.index(self)
         if indexofthisline > 0:
             previousline = self.hunk.changedlines[indexofthisline - 1]
             return previousline
         else:
             return None
 
     def parentitem(self):
         "return the parent to the current item"
         return self.hunk
 
     def firstchild(self):
         "return the first child of this item, if one exists.  otherwise None."
         # hunk-lines don't have children
         return None
 
     def lastchild(self):
         "return the last child of this item, if one exists.  otherwise None."
         # hunk-lines don't have children
         return None
 
 class uihunk(patchnode):
     """ui patch hunk, wraps a hunk and keep track of ui behavior """
     maxcontext = 3
 
     def __init__(self, hunk, header):
         self._hunk = hunk
         self.changedlines = [uihunkline(line, self) for line in hunk.hunk]
         self.header = header
         # used at end for detecting how many removed lines were un-applied
         self.originalremoved = self.removed
 
         # flag to indicate whether to display as folded/unfolded to user
         self.folded = True
         # flag to indicate whether to apply this chunk
         self.applied = True
         # flag which only affects the status display indicating if a node's
         # children are partially applied (i.e. some applied, some not).
         self.partial = False
 
     def nextsibling(self):
         numhunksinheader = len(self.header.hunks)
         indexofthishunk = self.header.hunks.index(self)
 
         if (indexofthishunk < numhunksinheader - 1):
             nexthunk = self.header.hunks[indexofthishunk + 1]
             return nexthunk
         else:
             return None
 
     def prevsibling(self):
         indexofthishunk = self.header.hunks.index(self)
         if indexofthishunk > 0:
             previoushunk = self.header.hunks[indexofthishunk - 1]
             return previoushunk
         else:
             return None
 
     def parentitem(self):
         "return the parent to the current item"
         return self.header
 
     def firstchild(self):
         "return the first child of this item, if one exists.  otherwise None."
         if len(self.changedlines) > 0:
             return self.changedlines[0]
         else:
             return None
 
     def lastchild(self):
         "return the last child of this item, if one exists.  otherwise None."
         if len(self.changedlines) > 0:
             return self.changedlines[-1]
         else:
             return None
 
     def allchildren(self):
         "return a list of all of the direct children of this node"
         return self.changedlines
 
     def countchanges(self):
         """changedlines -> (n+,n-)"""
         add = len([l for l in self.changedlines if l.applied
                     and l.prettystr().startswith('+')])
         rem = len([l for l in self.changedlines if l.applied
                     and l.prettystr().startswith('-')])
         return add, rem
 
     def getfromtoline(self):
         # calculate the number of removed lines converted to context lines
         removedconvertedtocontext = self.originalremoved - self.removed
 
         contextlen = (len(self.before) + len(self.after) +
                       removedconvertedtocontext)
         if self.after and self.after[-1] == '\\ No newline at end of file\n':
             contextlen -= 1
         fromlen = contextlen + self.removed
         tolen = contextlen + self.added
 
         # diffutils manual, section "2.2.2.2 detailed description of unified
         # format": "an empty hunk is considered to end at the line that
         # precedes the hunk."
         #
         # so, if either of hunks is empty, decrease its line start. --immerrr
         # but only do this if fromline > 0, to avoid having, e.g fromline=-1.
         fromline, toline = self.fromline, self.toline
         if fromline != 0:
             if fromlen == 0:
                 fromline -= 1
             if tolen == 0 and toline > 0:
                 toline -= 1
 
         fromtoline = '@@ -%d,%d +%d,%d @@%s\n' % (
             fromline, fromlen, toline, tolen,
             self.proc and (' ' + self.proc))
         return fromtoline
 
     def write(self, fp):
         # updated self.added/removed, which are used by getfromtoline()
         self.added, self.removed = self.countchanges()
         fp.write(self.getfromtoline())
 
         hunklinelist = []
         # add the following to the list: (1) all applied lines, and
         # (2) all unapplied removal lines (convert these to context lines)
         for changedline in self.changedlines:
             changedlinestr = changedline.prettystr()
             if changedline.applied:
                 hunklinelist.append(changedlinestr)
             elif changedlinestr.startswith("-"):
                 hunklinelist.append(" " + changedlinestr[1:])
 
         fp.write(''.join(self.before + hunklinelist + self.after))
 
     pretty = write
 
     def prettystr(self):
         x = stringio()
         self.pretty(x)
         return x.getvalue()
 
     def reversehunk(self):
         """return a recordhunk which is the reverse of the hunk
 
         Assuming the displayed patch is diff(A, B) result. The returned hunk is
         intended to be applied to B, instead of A.
 
         For example, when A is "0\n1\n2\n6\n" and B is "0\n3\n4\n5\n6\n", and
         the user made the following selection:
 
                  0
             [x] -1           [x]: selected
             [ ] -2           [ ]: not selected
             [x] +3
             [ ] +4
             [x] +5
                  6
 
         This function returns a hunk like:
 
                  0
                 -3
                 -4
                 -5
                 +1
                 +4
                  6
 
         Note "4" was first deleted then added. That's because "4" exists in B
         side and "-4" must exist between "-3" and "-5" to make the patch
         applicable to B.
         """
         dels = []
         adds = []
         for line in self.changedlines:
             text = line.linetext
             if line.applied:
                 if text.startswith('+'):
                     dels.append(text[1:])
                 elif text.startswith('-'):
                     adds.append(text[1:])
             elif text.startswith('+'):
                 dels.append(text[1:])
                 adds.append(text[1:])
         hunk = ['-%s' % l for l in dels] + ['+%s' % l for l in adds]
         h = self._hunk
         return patchmod.recordhunk(h.header, h.toline, h.fromline, h.proc,
                                    h.before, hunk, h.after)
 
     def __getattr__(self, name):
         return getattr(self._hunk, name)
 
     def __repr__(self):
         return r'<hunk %r@%d>' % (self.filename(), self.fromline)
 
 def filterpatch(ui, chunks, chunkselector, operation=None):
     """interactively filter patch chunks into applied-only chunks"""
     chunks = list(chunks)
     # convert chunks list into structure suitable for displaying/modifying
     # with curses.  create a list of headers only.
     headers = [c for c in chunks if isinstance(c, patchmod.header)]
 
     # if there are no changed files
     if len(headers) == 0:
         return [], {}
     uiheaders = [uiheader(h) for h in headers]
     # let user choose headers/hunks/lines, and mark their applied flags
     # accordingly
     ret = chunkselector(ui, uiheaders, operation=operation)
     appliedhunklist = []
     for hdr in uiheaders:
         if (hdr.applied and
             (hdr.special() or len([h for h in hdr.hunks if h.applied]) > 0)):
             appliedhunklist.append(hdr)
             fixoffset = 0
             for hnk in hdr.hunks:
                 if hnk.applied:
                     appliedhunklist.append(hnk)
                     # adjust the 'to'-line offset of the hunk to be correct
                     # after de-activating some of the other hunks for this file
                     if fixoffset:
                         #hnk = copy.copy(hnk) # necessary??
                         hnk.toline += fixoffset
                 else:
                     fixoffset += hnk.removed - hnk.added
 
     return (appliedhunklist, ret)
 
 def chunkselector(ui, headerlist, operation=None):
     """
     curses interface to get selection of chunks, and mark the applied flags
     of the chosen chunks.
     """
     ui.write(_('starting interactive selection\n'))
     chunkselector = curseschunkselector(headerlist, ui, operation)
+    # This is required for ncurses to display non-ASCII characters in
+    # default user locale encoding correctly.  --immerrr
+    locale.setlocale(locale.LC_ALL, r'')
     origsigtstp = sentinel = object()
     if util.safehasattr(signal, 'SIGTSTP'):
         origsigtstp = signal.getsignal(signal.SIGTSTP)
     try:
         curses.wrapper(chunkselector.main)
         if chunkselector.initexc is not None:
             raise chunkselector.initexc
         # ncurses does not restore signal handler for SIGTSTP
     finally:
         if origsigtstp is not sentinel:
             signal.signal(signal.SIGTSTP, origsigtstp)
     return chunkselector.opts
 
 def testdecorator(testfn, f):
     def u(*args, **kwargs):
         return f(testfn, *args, **kwargs)
     return u
 
 def testchunkselector(testfn, ui, headerlist, operation=None):
     """
     test interface to get selection of chunks, and mark the applied flags
     of the chosen chunks.
     """
     chunkselector = curseschunkselector(headerlist, ui, operation)
 
     class dummystdscr(object):
         def clear(self):
             pass
         def refresh(self):
             pass
 
     chunkselector.stdscr = dummystdscr()
     if testfn and os.path.exists(testfn):
         testf = open(testfn, 'rb')
         testcommands = [x.rstrip('\n') for x in testf.readlines()]
         testf.close()
         while True:
             if chunkselector.handlekeypressed(testcommands.pop(0), test=True):
                 break
     return chunkselector.opts
 
 _headermessages = { # {operation: text}
     'apply': _('Select hunks to apply'),
     'discard': _('Select hunks to discard'),
     'keep': _('Select hunks to keep'),
     None: _('Select hunks to record'),
 }
 
 class curseschunkselector(object):
     def __init__(self, headerlist, ui, operation=None):
         # put the headers into a patch object
         self.headerlist = patch(headerlist)
 
         self.ui = ui
         self.opts = {}
 
         self.errorstr = None
         # list of all chunks
         self.chunklist = []
         for h in headerlist:
             self.chunklist.append(h)
             self.chunklist.extend(h.hunks)
 
         # dictionary mapping (fgcolor, bgcolor) pairs to the
         # corresponding curses color-pair value.
         self.colorpairs = {}
         # maps custom nicknames of color-pairs to curses color-pair values
         self.colorpairnames = {}
 
         # Honor color setting of ui section. Keep colored setup as
         # long as not explicitly set to a falsy value - especially,
         # when not set at all. This is to stay most compatible with
         # previous (color only) behaviour.
         uicolor = stringutil.parsebool(self.ui.config('ui', 'color'))
         self.usecolor = uicolor is not False
 
         # the currently selected header, hunk, or hunk-line
         self.currentselecteditem = self.headerlist[0]
         self.lastapplieditem = None
 
         # updated when printing out patch-display -- the 'lines' here are the
         # line positions *in the pad*, not on the screen.
         self.selecteditemstartline = 0
         self.selecteditemendline = None
 
         # define indentation levels
         self.headerindentnumchars = 0
         self.hunkindentnumchars = 3
         self.hunklineindentnumchars = 6
 
         # the first line of the pad to print to the screen
         self.firstlineofpadtoprint = 0
 
         # keeps track of the number of lines in the pad
         self.numpadlines = None
 
         self.numstatuslines = 1
 
         # keep a running count of the number of lines printed to the pad
         # (used for determining when the selected item begins/ends)
         self.linesprintedtopadsofar = 0
 
         # the first line of the pad which is visible on the screen
         self.firstlineofpadtoprint = 0
 
         # stores optional text for a commit comment provided by the user
         self.commenttext = ""
 
         # if the last 'toggle all' command caused all changes to be applied
         self.waslasttoggleallapplied = True
 
         # affects some ui text
         if operation not in _headermessages:
             raise error.ProgrammingError('unexpected operation: %s' % operation)
         self.operation = operation
 
     def uparrowevent(self):
         """
         try to select the previous item to the current item that has the
         most-indented level.  for example, if a hunk is selected, try to select
         the last hunkline of the hunk prior to the selected hunk.  or, if
         the first hunkline of a hunk is currently selected, then select the
         hunk itself.
         """
         currentitem = self.currentselecteditem
 
         nextitem = currentitem.previtem()
 
         if nextitem is None:
             # if no parent item (i.e. currentitem is the first header), then
             # no change...
             nextitem = currentitem
 
         self.currentselecteditem = nextitem
 
     def uparrowshiftevent(self):
         """
         select (if possible) the previous item on the same level as the
         currently selected item.  otherwise, select (if possible) the
         parent-item of the currently selected item.
         """
         currentitem = self.currentselecteditem
         nextitem = currentitem.prevsibling()
         # if there's no previous sibling, try choosing the parent
         if nextitem is None:
             nextitem = currentitem.parentitem()
         if nextitem is None:
             # if no parent item (i.e. currentitem is the first header), then
             # no change...
             nextitem = currentitem
 
         self.currentselecteditem = nextitem
         self.recenterdisplayedarea()
 
     def downarrowevent(self):
         """
         try to select the next item to the current item that has the
         most-indented level.  for example, if a hunk is selected, select
         the first hunkline of the selected hunk.  or, if the last hunkline of
         a hunk is currently selected, then select the next hunk, if one exists,
         or if not, the next header if one exists.
         """
         #self.startprintline += 1 #debug
         currentitem = self.currentselecteditem
 
         nextitem = currentitem.nextitem()
         # if there's no next item, keep the selection as-is
         if nextitem is None:
             nextitem = currentitem
 
         self.currentselecteditem = nextitem
 
     def downarrowshiftevent(self):
         """
         select (if possible) the next item on the same level as the currently
         selected item.  otherwise, select (if possible) the next item on the
         same level as the parent item of the currently selected item.
         """
         currentitem = self.currentselecteditem
         nextitem = currentitem.nextsibling()
         # if there's no next sibling, try choosing the parent's nextsibling
         if nextitem is None:
             try:
                 nextitem = currentitem.parentitem().nextsibling()
             except AttributeError:
                 # parentitem returned None, so nextsibling() can't be called
                 nextitem = None
         if nextitem is None:
             # if parent has no next sibling, then no change...
             nextitem = currentitem
 
         self.currentselecteditem = nextitem
         self.recenterdisplayedarea()
 
     def nextsametype(self, test=False):
         currentitem = self.currentselecteditem
         sametype = lambda item: isinstance(item, type(currentitem))
         nextitem = currentitem.nextitem()
 
         while nextitem is not None and not sametype(nextitem):
             nextitem = nextitem.nextitem()
 
         if nextitem is None:
             nextitem = currentitem
         else:
             parent = nextitem.parentitem()
             if parent is not None and parent.folded:
                 self.togglefolded(parent)
 
         self.currentselecteditem = nextitem
         if not test:
             self.recenterdisplayedarea()
 
     def rightarrowevent(self):
         """
         select (if possible) the first of this item's child-items.
         """
         currentitem = self.currentselecteditem
         nextitem = currentitem.firstchild()
 
         # turn off folding if we want to show a child-item
         if currentitem.folded:
             self.togglefolded(currentitem)
 
         if nextitem is None:
             # if no next item on parent-level, then no change...
             nextitem = currentitem
 
         self.currentselecteditem = nextitem
 
     def leftarrowevent(self):
         """
         if the current item can be folded (i.e. it is an unfolded header or
         hunk), then fold it.  otherwise try select (if possible) the parent
         of this item.
         """
         currentitem = self.currentselecteditem
 
         # try to fold the item
         if not isinstance(currentitem, uihunkline):
             if not currentitem.folded:
                 self.togglefolded(item=currentitem)
                 return
 
         # if it can't be folded, try to select the parent item
         nextitem = currentitem.parentitem()
 
         if nextitem is None:
             # if no item on parent-level, then no change...
             nextitem = currentitem
             if not nextitem.folded:
                 self.togglefolded(item=nextitem)
 
         self.currentselecteditem = nextitem
 
     def leftarrowshiftevent(self):
         """
         select the header of the current item (or fold current item if the
         current item is already a header).
         """
         currentitem = self.currentselecteditem
 
         if isinstance(currentitem, uiheader):
             if not currentitem.folded:
                 self.togglefolded(item=currentitem)
                 return
 
         # select the parent item recursively until we're at a header
         while True:
             nextitem = currentitem.parentitem()
             if nextitem is None:
                 break
             else:
                 currentitem = nextitem
 
         self.currentselecteditem = currentitem
 
     def updatescroll(self):
         "scroll the screen to fully show the currently-selected"
         selstart = self.selecteditemstartline
         selend = self.selecteditemendline
 
         padstart = self.firstlineofpadtoprint
         padend = padstart + self.yscreensize - self.numstatuslines - 1
         # 'buffered' pad start/end values which scroll with a certain
         # top/bottom context margin
         padstartbuffered = padstart + 3
         padendbuffered = padend - 3
 
         if selend > padendbuffered:
             self.scrolllines(selend - padendbuffered)
         elif selstart < padstartbuffered:
             # negative values scroll in pgup direction
             self.scrolllines(selstart - padstartbuffered)
 
     def scrolllines(self, numlines):
         "scroll the screen up (down) by numlines when numlines >0 (<0)."
         self.firstlineofpadtoprint += numlines
         if self.firstlineofpadtoprint < 0:
             self.firstlineofpadtoprint = 0
         if self.firstlineofpadtoprint > self.numpadlines - 1:
             self.firstlineofpadtoprint = self.numpadlines - 1
 
     def toggleapply(self, item=None):
         """
         toggle the applied flag of the specified item.  if no item is specified,
         toggle the flag of the currently selected item.
         """
         if item is None:
             item = self.currentselecteditem
             # Only set this when NOT using 'toggleall'
             self.lastapplieditem = item
 
         item.applied = not item.applied
 
         if isinstance(item, uiheader):
             item.partial = False
             if item.applied:
                 # apply all its hunks
                 for hnk in item.hunks:
                     hnk.applied = True
                     # apply all their hunklines
                     for hunkline in hnk.changedlines:
                         hunkline.applied = True
             else:
                 # un-apply all its hunks
                 for hnk in item.hunks:
                     hnk.applied = False
                     hnk.partial = False
                     # un-apply all their hunklines
                     for hunkline in hnk.changedlines:
                         hunkline.applied = False
         elif isinstance(item, uihunk):
             item.partial = False
             # apply all it's hunklines
             for hunkline in item.changedlines:
                 hunkline.applied = item.applied
 
             siblingappliedstatus = [hnk.applied for hnk in item.header.hunks]
             allsiblingsapplied = not (False in siblingappliedstatus)
             nosiblingsapplied = not (True in siblingappliedstatus)
 
             siblingspartialstatus = [hnk.partial for hnk in item.header.hunks]
             somesiblingspartial = (True in siblingspartialstatus)
 
             #cases where applied or partial should be removed from header
 
             # if no 'sibling' hunks are applied (including this hunk)
             if nosiblingsapplied:
                 if not item.header.special():
                     item.header.applied = False
                     item.header.partial = False
             else: # some/all parent siblings are applied
                 item.header.applied = True
                 item.header.partial = (somesiblingspartial or
                                         not allsiblingsapplied)
 
         elif isinstance(item, uihunkline):
             siblingappliedstatus = [ln.applied for ln in item.hunk.changedlines]
             allsiblingsapplied = not (False in siblingappliedstatus)
             nosiblingsapplied = not (True in siblingappliedstatus)
 
             # if no 'sibling' lines are applied
             if nosiblingsapplied:
                 item.hunk.applied = False
                 item.hunk.partial = False
             elif allsiblingsapplied:
                 item.hunk.applied = True
                 item.hunk.partial = False
             else: # some siblings applied
                 item.hunk.applied = True
                 item.hunk.partial = True
 
             parentsiblingsapplied = [hnk.applied for hnk
                                      in item.hunk.header.hunks]
             noparentsiblingsapplied = not (True in parentsiblingsapplied)
             allparentsiblingsapplied = not (False in parentsiblingsapplied)
 
             parentsiblingspartial = [hnk.partial for hnk
                                      in item.hunk.header.hunks]
             someparentsiblingspartial = (True in parentsiblingspartial)
 
             # if all parent hunks are not applied, un-apply header
             if noparentsiblingsapplied:
                 if not item.hunk.header.special():
                     item.hunk.header.applied = False
                     item.hunk.header.partial = False
             # set the applied and partial status of the header if needed
             else: # some/all parent siblings are applied
                 item.hunk.header.applied = True
                 item.hunk.header.partial = (someparentsiblingspartial or
                                             not allparentsiblingsapplied)
 
     def toggleall(self):
         "toggle the applied flag of all items."
         if self.waslasttoggleallapplied: # then unapply them this time
             for item in self.headerlist:
                 if item.applied:
                     self.toggleapply(item)
         else:
             for item in self.headerlist:
                 if not item.applied:
                     self.toggleapply(item)
         self.waslasttoggleallapplied = not self.waslasttoggleallapplied
 
     def toggleallbetween(self):
         "toggle applied on or off for all items in range [lastapplied,current]."
         if (not self.lastapplieditem or
             self.currentselecteditem == self.lastapplieditem):
             # Treat this like a normal 'x'/' '
             self.toggleapply()
             return
 
         startitem = self.lastapplieditem
         enditem = self.currentselecteditem
         # Verify that enditem is "after" startitem, otherwise swap them.
         for direction in ['forward', 'reverse']:
             nextitem = startitem.nextitem()
             while nextitem and nextitem != enditem:
                 nextitem = nextitem.nextitem()
             if nextitem:
                 break
             # Looks like we went the wrong direction :)
             startitem, enditem = enditem, startitem
 
         if not nextitem:
             # We didn't find a path going either forward or backward? Don't know
             # how this can happen, let's not crash though.
             return
 
         nextitem = startitem
         # Switch all items to be the opposite state of the currently selected
         # item. Specifically:
         #  [ ] startitem
         #  [x] middleitem
         #  [ ] enditem  <-- currently selected
         # This will turn all three on, since the currently selected item is off.
         # This does *not* invert each item (i.e. middleitem stays marked/on)
         desiredstate = not self.currentselecteditem.applied
         while nextitem != enditem.nextitem():
             if nextitem.applied != desiredstate:
                 self.toggleapply(item=nextitem)
             nextitem = nextitem.nextitem()
 
     def togglefolded(self, item=None, foldparent=False):
         "toggle folded flag of specified item (defaults to currently selected)"
         if item is None:
             item = self.currentselecteditem
         if foldparent or (isinstance(item, uiheader) and item.neverunfolded):
             if not isinstance(item, uiheader):
                 # we need to select the parent item in this case
                 self.currentselecteditem = item = item.parentitem()
             elif item.neverunfolded:
                 item.neverunfolded = False
 
             # also fold any foldable children of the parent/current item
             if isinstance(item, uiheader): # the original or 'new' item
                 for child in item.allchildren():
                     child.folded = not item.folded
 
         if isinstance(item, (uiheader, uihunk)):
             item.folded = not item.folded
 
     def alignstring(self, instr, window):
         """
         add whitespace to the end of a string in order to make it fill
         the screen in the x direction.  the current cursor position is
         taken into account when making this calculation.  the string can span
         multiple lines.
         """
         y, xstart = window.getyx()
         width = self.xscreensize
         # turn tabs into spaces
         instr = instr.expandtabs(4)
         strwidth = encoding.colwidth(instr)
         numspaces = (width - ((strwidth + xstart) % width))
         return instr + " " * numspaces
 
     def printstring(self, window, text, fgcolor=None, bgcolor=None, pair=None,
         pairname=None, attrlist=None, towin=True, align=True, showwhtspc=False):
         """
         print the string, text, with the specified colors and attributes, to
         the specified curses window object.
 
         the foreground and background colors are of the form
         curses.color_xxxx, where xxxx is one of: [black, blue, cyan, green,
         magenta, red, white, yellow].  if pairname is provided, a color
         pair will be looked up in the self.colorpairnames dictionary.
 
         attrlist is a list containing text attributes in the form of
         curses.a_xxxx, where xxxx can be: [bold, dim, normal, standout,
         underline].
 
         if align == True, whitespace is added to the printed string such that
         the string stretches to the right border of the window.
 
         if showwhtspc == True, trailing whitespace of a string is highlighted.
         """
         # preprocess the text, converting tabs to spaces
         text = text.expandtabs(4)
         # strip \n, and convert control characters to ^[char] representation
         text = re.sub(br'[\x00-\x08\x0a-\x1f]',
                 lambda m:'^' + chr(ord(m.group()) + 64), text.strip('\n'))
 
         if pair is not None:
             colorpair = pair
         elif pairname is not None:
             colorpair = self.colorpairnames[pairname]
         else:
             if fgcolor is None:
                 fgcolor = -1
             if bgcolor is None:
                 bgcolor = -1
             if (fgcolor, bgcolor) in self.colorpairs:
                 colorpair = self.colorpairs[(fgcolor, bgcolor)]
             else:
                 colorpair = self.getcolorpair(fgcolor, bgcolor)
         # add attributes if possible
         if attrlist is None:
             attrlist = []
         if colorpair < 256:
             # then it is safe to apply all attributes
             for textattr in attrlist:
                 colorpair |= textattr
         else:
             # just apply a select few (safe?) attributes
             for textattr in (curses.A_UNDERLINE, curses.A_BOLD):
                 if textattr in attrlist:
                     colorpair |= textattr
 
         y, xstart = self.chunkpad.getyx()
         t = "" # variable for counting lines printed
         # if requested, show trailing whitespace
         if showwhtspc:
             origlen = len(text)
             text = text.rstrip(' \n') # tabs have already been expanded
             strippedlen = len(text)
             numtrailingspaces = origlen - strippedlen
 
         if towin:
             window.addstr(text, colorpair)
         t += text
 
         if showwhtspc:
                 wscolorpair = colorpair | curses.A_REVERSE
                 if towin:
                     for i in range(numtrailingspaces):
                         window.addch(curses.ACS_CKBOARD, wscolorpair)
                 t += " " * numtrailingspaces
 
         if align:
             if towin:
                 extrawhitespace = self.alignstring("", window)
                 window.addstr(extrawhitespace, colorpair)
             else:
                 # need to use t, since the x position hasn't incremented
                 extrawhitespace = self.alignstring(t, window)
             t += extrawhitespace
 
         # is reset to 0 at the beginning of printitem()
 
         linesprinted = (xstart + len(t)) / self.xscreensize
         self.linesprintedtopadsofar += linesprinted
         return t
 
     def _getstatuslinesegments(self):
         """-> [str]. return segments"""
         selected = self.currentselecteditem.applied
         spaceselect = _('space/enter: select')
         spacedeselect = _('space/enter: deselect')
         # Format the selected label into a place as long as the longer of the
         # two possible labels.  This may vary by language.
         spacelen = max(len(spaceselect), len(spacedeselect))
         selectedlabel = '%-*s' % (spacelen,
                                   spacedeselect if selected else spaceselect)
         segments = [
             _headermessages[self.operation],
             '-',
             _('[x]=selected **=collapsed'),
             _('c: confirm'),
             _('q: abort'),
             _('arrow keys: move/expand/collapse'),
             selectedlabel,
             _('?: help'),
         ]
         return segments
 
     def _getstatuslines(self):
         """() -> [str]. return short help used in the top status window"""
         if self.errorstr is not None:
             lines = [self.errorstr, _('Press any key to continue')]
         else:
             # wrap segments to lines
             segments = self._getstatuslinesegments()
             width = self.xscreensize
             lines = []
             lastwidth = width
             for s in segments:
                 w = encoding.colwidth(s)
                 sep = ' ' * (1 + (s and s[0] not in '-['))
                 if lastwidth + w + len(sep) >= width:
                     lines.append(s)
                     lastwidth = w
                 else:
                     lines[-1] += sep + s
                     lastwidth += w + len(sep)
         if len(lines) != self.numstatuslines:
             self.numstatuslines = len(lines)
             self.statuswin.resize(self.numstatuslines, self.xscreensize)
         return [stringutil.ellipsis(l, self.xscreensize - 1) for l in lines]
 
     def updatescreen(self):
         self.statuswin.erase()
         self.chunkpad.erase()
 
         printstring = self.printstring
 
         # print out the status lines at the top
         try:
             for line in self._getstatuslines():
                 printstring(self.statuswin, line, pairname="legend")
             self.statuswin.refresh()
         except curses.error:
             pass
         if self.errorstr is not None:
             return
 
         # print out the patch in the remaining part of the window
         try:
             self.printitem()
             self.updatescroll()
             self.chunkpad.refresh(self.firstlineofpadtoprint, 0,
                                   self.numstatuslines, 0,
                                   self.yscreensize - self.numstatuslines,
                                   self.xscreensize)
         except curses.error:
             pass
 
     def getstatusprefixstring(self, item):
         """
         create a string to prefix a line with which indicates whether 'item'
         is applied and/or folded.
         """
 
         # create checkbox string
         if item.applied:
             if not isinstance(item, uihunkline) and item.partial:
                 checkbox = "[~]"
             else:
                 checkbox = "[x]"
         else:
             checkbox = "[ ]"
 
         try:
             if item.folded:
                 checkbox += "**"
                 if isinstance(item, uiheader):
                     # one of "m", "a", or "d" (modified, added, deleted)
                     filestatus = item.changetype
 
                     checkbox += filestatus + " "
             else:
                 checkbox += "  "
                 if isinstance(item, uiheader):
                     # add two more spaces for headers
                     checkbox += "  "
         except AttributeError: # not foldable
             checkbox += "  "
 
         return checkbox
 
     def printheader(self, header, selected=False, towin=True,
                     ignorefolding=False):
         """
         print the header to the pad.  if countlines is True, don't print
         anything, but just count the number of lines which would be printed.
         """
 
         outstr = ""
         text = header.prettystr()
         chunkindex = self.chunklist.index(header)
 
         if chunkindex != 0 and not header.folded:
             # add separating line before headers
             outstr += self.printstring(self.chunkpad, '_' * self.xscreensize,
                                        towin=towin, align=False)
         # select color-pair based on if the header is selected
         colorpair = self.getcolorpair(name=selected and "selected" or "normal",
                                       attrlist=[curses.A_BOLD])
 
         # print out each line of the chunk, expanding it to screen width
 
         # number of characters to indent lines on this level by
         indentnumchars = 0
         checkbox = self.getstatusprefixstring(header)
         if not header.folded or ignorefolding:
             textlist = text.split("\n")
             linestr = checkbox + textlist[0]
         else:
             linestr = checkbox + header.filename()
         outstr += self.printstring(self.chunkpad, linestr, pair=colorpair,
                                    towin=towin)
         if not header.folded or ignorefolding:
             if len(textlist) > 1:
                 for line in textlist[1:]:
                     linestr = " "*(indentnumchars + len(checkbox)) + line
                     outstr += self.printstring(self.chunkpad, linestr,
                                                pair=colorpair, towin=towin)
 
         return outstr
 
     def printhunklinesbefore(self, hunk, selected=False, towin=True,
                              ignorefolding=False):
         "includes start/end line indicator"
         outstr = ""
         # where hunk is in list of siblings
         hunkindex = hunk.header.hunks.index(hunk)
 
         if hunkindex != 0:
             # add separating line before headers
             outstr += self.printstring(self.chunkpad, ' '*self.xscreensize,
                                        towin=towin, align=False)
 
         colorpair = self.getcolorpair(name=selected and "selected" or "normal",
                                       attrlist=[curses.A_BOLD])
 
         # print out from-to line with checkbox
         checkbox = self.getstatusprefixstring(hunk)
 
         lineprefix = " "*self.hunkindentnumchars + checkbox
         frtoline = "   " + hunk.getfromtoline().strip("\n")
 
         outstr += self.printstring(self.chunkpad, lineprefix, towin=towin,
                                    align=False) # add uncolored checkbox/indent
         outstr += self.printstring(self.chunkpad, frtoline, pair=colorpair,
                                    towin=towin)
 
         if hunk.folded and not ignorefolding:
             # skip remainder of output
             return outstr
 
         # print out lines of the chunk preceeding changed-lines
         for line in hunk.before:
             linestr = " "*(self.hunklineindentnumchars + len(checkbox)) + line
             outstr += self.printstring(self.chunkpad, linestr, towin=towin)
 
         return outstr
 
     def printhunklinesafter(self, hunk, towin=True, ignorefolding=False):
         outstr = ""
         if hunk.folded and not ignorefolding:
             return outstr
 
         # a bit superfluous, but to avoid hard-coding indent amount
         checkbox = self.getstatusprefixstring(hunk)
         for line in hunk.after:
             linestr = " "*(self.hunklineindentnumchars + len(checkbox)) + line
             outstr += self.printstring(self.chunkpad, linestr, towin=towin)
 
         return outstr
 
     def printhunkchangedline(self, hunkline, selected=False, towin=True):
         outstr = ""
         checkbox = self.getstatusprefixstring(hunkline)
 
         linestr = hunkline.prettystr().strip("\n")
 
         # select color-pair based on whether line is an addition/removal
         if selected:
             colorpair = self.getcolorpair(name="selected")
         elif linestr.startswith("+"):
             colorpair = self.getcolorpair(name="addition")
         elif linestr.startswith("-"):
             colorpair = self.getcolorpair(name="deletion")
         elif linestr.startswith("\\"):
             colorpair = self.getcolorpair(name="normal")
 
         lineprefix = " "*self.hunklineindentnumchars + checkbox
         outstr += self.printstring(self.chunkpad, lineprefix, towin=towin,
                                    align=False) # add uncolored checkbox/indent
         outstr += self.printstring(self.chunkpad, linestr, pair=colorpair,
                                    towin=towin, showwhtspc=True)
         return outstr
 
     def printitem(self, item=None, ignorefolding=False, recursechildren=True,
                   towin=True):
         """
         use __printitem() to print the the specified item.applied.
         if item is not specified, then print the entire patch.
         (hiding folded elements, etc. -- see __printitem() docstring)
         """
 
         if item is None:
             item = self.headerlist
         if recursechildren:
             self.linesprintedtopadsofar = 0
 
         outstr = []
         self.__printitem(item, ignorefolding, recursechildren, outstr,
                                   towin=towin)
         return ''.join(outstr)
 
     def outofdisplayedarea(self):
         y, _ = self.chunkpad.getyx() # cursor location
         # * 2 here works but an optimization would be the max number of
         # consecutive non selectable lines
         # i.e the max number of context line for any hunk in the patch
         miny = min(0, self.firstlineofpadtoprint - self.yscreensize)
         maxy = self.firstlineofpadtoprint + self.yscreensize * 2
         return y < miny or y > maxy
 
     def handleselection(self, item, recursechildren):
         selected = (item is self.currentselecteditem)
         if selected and recursechildren:
             # assumes line numbering starting from line 0
             self.selecteditemstartline = self.linesprintedtopadsofar
             selecteditemlines = self.getnumlinesdisplayed(item,
                                                           recursechildren=False)
             self.selecteditemendline = (self.selecteditemstartline +
                                         selecteditemlines - 1)
         return selected
 
     def __printitem(self, item, ignorefolding, recursechildren, outstr,
                     towin=True):
         """
         recursive method for printing out patch/header/hunk/hunk-line data to
         screen.  also returns a string with all of the content of the displayed
         patch (not including coloring, etc.).
 
         if ignorefolding is True, then folded items are printed out.
 
         if recursechildren is False, then only print the item without its
         child items.
         """
 
         if towin and self.outofdisplayedarea():
             return
 
         selected = self.handleselection(item, recursechildren)
 
         # patch object is a list of headers
         if isinstance(item, patch):
             if recursechildren:
                 for hdr in item:
                     self.__printitem(hdr, ignorefolding,
                             recursechildren, outstr, towin)
         # todo: eliminate all isinstance() calls
         if isinstance(item, uiheader):
             outstr.append(self.printheader(item, selected, towin=towin,
                                        ignorefolding=ignorefolding))
             if recursechildren:
                 for hnk in item.hunks:
                     self.__printitem(hnk, ignorefolding,
                             recursechildren, outstr, towin)
         elif (isinstance(item, uihunk) and
               ((not item.header.folded) or ignorefolding)):
             # print the hunk data which comes before the changed-lines
             outstr.append(self.printhunklinesbefore(item, selected, towin=towin,
                                                 ignorefolding=ignorefolding))
             if recursechildren:
                 for l in item.changedlines:
                     self.__printitem(l, ignorefolding,
                             recursechildren, outstr, towin)
                 outstr.append(self.printhunklinesafter(item, towin=towin,
                                                 ignorefolding=ignorefolding))
         elif (isinstance(item, uihunkline) and
               ((not item.hunk.folded) or ignorefolding)):
             outstr.append(self.printhunkchangedline(item, selected,
                 towin=towin))
 
         return outstr
 
     def getnumlinesdisplayed(self, item=None, ignorefolding=False,
                              recursechildren=True):
         """
         return the number of lines which would be displayed if the item were
         to be printed to the display.  the item will not be printed to the
         display (pad).
         if no item is given, assume the entire patch.
         if ignorefolding is True, folded items will be unfolded when counting
         the number of lines.
         """
 
         # temporarily disable printing to windows by printstring
         patchdisplaystring = self.printitem(item, ignorefolding,
                                             recursechildren, towin=False)
         numlines = len(patchdisplaystring) // self.xscreensize
         return numlines
 
     def sigwinchhandler(self, n, frame):
         "handle window resizing"
         try:
             curses.endwin()
             self.xscreensize, self.yscreensize = scmutil.termsize(self.ui)
             self.statuswin.resize(self.numstatuslines, self.xscreensize)
             self.numpadlines = self.getnumlinesdisplayed(ignorefolding=True) + 1
             self.chunkpad = curses.newpad(self.numpadlines, self.xscreensize)
         except curses.error:
             pass
 
     def getcolorpair(self, fgcolor=None, bgcolor=None, name=None,
                      attrlist=None):
         """
         get a curses color pair, adding it to self.colorpairs if it is not
         already defined.  an optional string, name, can be passed as a shortcut
         for referring to the color-pair.  by default, if no arguments are
         specified, the white foreground / black background color-pair is
         returned.
 
         it is expected that this function will be used exclusively for
         initializing color pairs, and not curses.init_pair().
 
         attrlist is used to 'flavor' the returned color-pair.  this information
         is not stored in self.colorpairs.  it contains attribute values like
         curses.A_BOLD.
         """
 
         if (name is not None) and name in self.colorpairnames:
             # then get the associated color pair and return it
             colorpair = self.colorpairnames[name]
         else:
             if fgcolor is None:
                 fgcolor = -1
             if bgcolor is None:
                 bgcolor = -1
             if (fgcolor, bgcolor) in self.colorpairs:
                 colorpair = self.colorpairs[(fgcolor, bgcolor)]
             else:
                 pairindex = len(self.colorpairs) + 1
                 if self.usecolor:
                     curses.init_pair(pairindex, fgcolor, bgcolor)
                     colorpair = self.colorpairs[(fgcolor, bgcolor)] = (
                         curses.color_pair(pairindex))
                     if name is not None:
                         self.colorpairnames[name] = curses.color_pair(pairindex)
                 else:
                     cval = 0
                     if name is not None:
                         if name == 'selected':
                             cval = curses.A_REVERSE
                         self.colorpairnames[name] = cval
                     colorpair = self.colorpairs[(fgcolor, bgcolor)] = cval
 
         # add attributes if possible
         if attrlist is None:
             attrlist = []
         if colorpair < 256:
             # then it is safe to apply all attributes
             for textattr in attrlist:
                 colorpair |= textattr
         else:
             # just apply a select few (safe?) attributes
             for textattrib in (curses.A_UNDERLINE, curses.A_BOLD):
                 if textattrib in attrlist:
                     colorpair |= textattrib
         return colorpair
 
     def initcolorpair(self, *args, **kwargs):
         "same as getcolorpair."
         self.getcolorpair(*args, **kwargs)
 
     def helpwindow(self):
         "print a help window to the screen.  exit after any keypress."
         helptext = _(
             """            [press any key to return to the patch-display]
 
 crecord allows you to interactively choose among the changes you have made,
 and confirm only those changes you select for further processing by the command
 you are running (commit/shelve/revert), after confirming the selected
 changes, the unselected changes are still present in your working copy, so you
 can use crecord multiple times to split large changes into smaller changesets.
 the following are valid keystrokes:
 
               x [space] : (un-)select item ([~]/[x] = partly/fully applied)
                 [enter] : (un-)select item and go to next item of same type
                       A : (un-)select all items
                       X : (un-)select all items between current and most-recent
     up/down-arrow [k/j] : go to previous/next unfolded item
         pgup/pgdn [K/J] : go to previous/next item of same type
  right/left-arrow [l/h] : go to child item / parent item
  shift-left-arrow   [H] : go to parent header / fold selected header
                       g : go to the top
                       G : go to the bottom
                       f : fold / unfold item, hiding/revealing its children
                       F : fold / unfold parent item and all of its ancestors
                  ctrl-l : scroll the selected line to the top of the screen
                       m : edit / resume editing the commit message
                       e : edit the currently selected hunk
                       a : toggle amend mode, only with commit -i
                       c : confirm selected changes
                       r : review/edit and confirm selected changes
                       q : quit without confirming (no changes will be made)
                       ? : help (what you're currently reading)""")
 
         helpwin = curses.newwin(self.yscreensize, 0, 0, 0)
         helplines = helptext.split("\n")
         helplines = helplines + [" "]*(
             self.yscreensize - self.numstatuslines - len(helplines) - 1)
         try:
             for line in helplines:
                 self.printstring(helpwin, line, pairname="legend")
         except curses.error:
             pass
         helpwin.refresh()
         try:
             with self.ui.timeblockedsection('crecord'):
                 helpwin.getkey()
         except curses.error:
             pass
 
     def commitMessageWindow(self):
         "Create a temporary commit message editing window on the screen."
 
         curses.raw()
         curses.def_prog_mode()
         curses.endwin()
         self.commenttext = self.ui.edit(self.commenttext, self.ui.username())
         curses.cbreak()
         self.stdscr.refresh()
         self.stdscr.keypad(1) # allow arrow-keys to continue to function
 
     def handlefirstlineevent(self):
         """
         Handle 'g' to navigate to the top most file in the ncurses window.
         """
         self.currentselecteditem = self.headerlist[0]
         currentitem = self.currentselecteditem
         # select the parent item recursively until we're at a header
         while True:
             nextitem = currentitem.parentitem()
             if nextitem is None:
                 break
             else:
                 currentitem = nextitem
 
         self.currentselecteditem = currentitem
 
     def handlelastlineevent(self):
         """
         Handle 'G' to navigate to the bottom most file/hunk/line depending
         on the whether the fold is active or not.
 
         If the bottom most file is folded, it navigates to that file and
         stops there. If the bottom most file is unfolded, it navigates to
         the bottom most hunk in that file and stops there. If the bottom most
         hunk is unfolded, it navigates to the bottom most line in that hunk.
         """
         currentitem = self.currentselecteditem
         nextitem = currentitem.nextitem()
         # select the child item recursively until we're at a footer
         while nextitem is not None:
             nextitem = currentitem.nextitem()
             if nextitem is None:
                 break
             else:
                 currentitem = nextitem
 
         self.currentselecteditem = currentitem
         self.recenterdisplayedarea()
 
     def confirmationwindow(self, windowtext):
         "display an informational window, then wait for and return a keypress."
 
         confirmwin = curses.newwin(self.yscreensize, 0, 0, 0)
         try:
             lines = windowtext.split("\n")
             for line in lines:
                 self.printstring(confirmwin, line, pairname="selected")
         except curses.error:
             pass
         self.stdscr.refresh()
         confirmwin.refresh()
         try:
             with self.ui.timeblockedsection('crecord'):
                 response = chr(self.stdscr.getch())
         except ValueError:
             response = None
 
         return response
 
     def reviewcommit(self):
         """ask for 'y' to be pressed to confirm selected. return True if
         confirmed."""
         confirmtext = _(
 """If you answer yes to the following, your currently chosen patch chunks
 will be loaded into an editor. To modify the patch, make the changes in your
 editor and save. To accept the current patch as-is, close the editor without
 saving.
 
 note: don't add/remove lines unless you also modify the range information.
       failing to follow this rule will result in the commit aborting.
 
 are you sure you want to review/edit and confirm the selected changes [yn]?
 """)
         with self.ui.timeblockedsection('crecord'):
             response = self.confirmationwindow(confirmtext)
         if response is None:
             response = "n"
         if response.lower().startswith("y"):
             return True
         else:
             return False
 
     def toggleamend(self, opts, test):
         """Toggle the amend flag.
 
         When the amend flag is set, a commit will modify the most recently
         committed changeset, instead of creating a new changeset.  Otherwise, a
         new changeset will be created (the normal commit behavior).
         """
 
         if opts.get('amend') is None:
             opts['amend'] = True
             msg = _("Amend option is turned on -- committing the currently "
                     "selected changes will not create a new changeset, but "
                     "instead update the most recently committed changeset.\n\n"
                     "Press any key to continue.")
         elif opts.get('amend') is True:
             opts['amend'] = None
             msg = _("Amend option is turned off -- committing the currently "
                     "selected changes will create a new changeset.\n\n"
                     "Press any key to continue.")
         if not test:
             self.confirmationwindow(msg)
 
     def recenterdisplayedarea(self):
         """
         once we scrolled with pg up pg down we can be pointing outside of the
         display zone. we print the patch with towin=False to compute the
         location of the selected item even though it is outside of the displayed
         zone and then update the scroll.
         """
         self.printitem(towin=False)
         self.updatescroll()
 
     def toggleedit(self, item=None, test=False):
         """
         edit the currently selected chunk
         """
         def updateui(self):
             self.numpadlines = self.getnumlinesdisplayed(ignorefolding=True) + 1
             self.chunkpad = curses.newpad(self.numpadlines, self.xscreensize)
             self.updatescroll()
             self.stdscr.refresh()
             self.statuswin.refresh()
             self.stdscr.keypad(1)
 
         def editpatchwitheditor(self, chunk):
             if chunk is None:
                 self.ui.write(_('cannot edit patch for whole file'))
                 self.ui.write("\n")
                 return None
             if chunk.header.binary():
                 self.ui.write(_('cannot edit patch for binary file'))
                 self.ui.write("\n")
                 return None
 
             # write the initial patch
             patch = stringio()
             patch.write(diffhelptext + hunkhelptext)
             chunk.header.write(patch)
             chunk.write(patch)
 
             # start the editor and wait for it to complete
             try:
                 patch = self.ui.edit(patch.getvalue(), "", action="diff")
             except error.Abort as exc:
                 self.errorstr = str(exc)
                 return None
             finally:
                 self.stdscr.clear()
                 self.stdscr.refresh()
 
             # remove comment lines
             patch = [line + '\n' for line in patch.splitlines()
                      if not line.startswith('#')]
             return patchmod.parsepatch(patch)
 
         if item is None:
             item = self.currentselecteditem
         if isinstance(item, uiheader):
             return
         if isinstance(item, uihunkline):
             item = item.parentitem()
         if not isinstance(item, uihunk):
             return
 
         # To go back to that hunk or its replacement at the end of the edit
         itemindex = item.parentitem().hunks.index(item)
 
         beforeadded, beforeremoved = item.added, item.removed
         newpatches = editpatchwitheditor(self, item)
         if newpatches is None:
             if not test:
                 updateui(self)
             return
         header = item.header
         editedhunkindex = header.hunks.index(item)
         hunksbefore = header.hunks[:editedhunkindex]
         hunksafter = header.hunks[editedhunkindex + 1:]
         newpatchheader = newpatches[0]
         newhunks = [uihunk(h, header) for h in newpatchheader.hunks]
         newadded = sum([h.added for h in newhunks])
         newremoved = sum([h.removed for h in newhunks])
         offset = (newadded - beforeadded) - (newremoved - beforeremoved)
 
         for h in hunksafter:
             h.toline += offset
         for h in newhunks:
             h.folded = False
         header.hunks = hunksbefore + newhunks + hunksafter
         if self.emptypatch():
             header.hunks = hunksbefore + [item] + hunksafter
         self.currentselecteditem = header
         if len(header.hunks) > itemindex:
             self.currentselecteditem = header.hunks[itemindex]
 
         if not test:
             updateui(self)
 
     def emptypatch(self):
         item = self.headerlist
         if not item:
             return True
         for header in item:
             if header.hunks:
                 return False
         return True
 
     def handlekeypressed(self, keypressed, test=False):
         """
         Perform actions based on pressed keys.
 
         Return true to exit the main loop.
         """
         keypressed = pycompat.bytestr(keypressed)
         if keypressed in ["k", "KEY_UP"]:
             self.uparrowevent()
         elif keypressed in ["K", "KEY_PPAGE"]:
             self.uparrowshiftevent()
         elif keypressed in ["j", "KEY_DOWN"]:
             self.downarrowevent()
         elif keypressed in ["J", "KEY_NPAGE"]:
             self.downarrowshiftevent()
         elif keypressed in ["l", "KEY_RIGHT"]:
             self.rightarrowevent()
         elif keypressed in ["h", "KEY_LEFT"]:
             self.leftarrowevent()
         elif keypressed in ["H", "KEY_SLEFT"]:
             self.leftarrowshiftevent()
         elif keypressed in ["q"]:
             raise error.Abort(_('user quit'))
         elif keypressed in ['a']:
             self.toggleamend(self.opts, test)
         elif keypressed in ["c"]:
             return True
         elif keypressed in ["r"]:
             if self.reviewcommit():
                 self.opts['review'] = True
                 return True
         elif test and keypressed in ['R']:
             self.opts['review'] = True
             return True
         elif keypressed in [' ', 'x']:
             self.toggleapply()
         elif keypressed in ['\n', 'KEY_ENTER']:
             self.toggleapply()
             self.nextsametype(test=test)
         elif keypressed in ['X']:
             self.toggleallbetween()
         elif keypressed in ['A']:
             self.toggleall()
         elif keypressed in ['e']:
             self.toggleedit(test=test)
         elif keypressed in ["f"]:
             self.togglefolded()
         elif keypressed in ["F"]:
             self.togglefolded(foldparent=True)
         elif keypressed in ["m"]:
             self.commitMessageWindow()
         elif keypressed in ["g", "KEY_HOME"]:
             self.handlefirstlineevent()
         elif keypressed in ["G", "KEY_END"]:
             self.handlelastlineevent()
         elif keypressed in ["?"]:
             self.helpwindow()
             self.stdscr.clear()
             self.stdscr.refresh()
         elif curses.unctrl(keypressed) in ["^L"]:
             # scroll the current line to the top of the screen, and redraw
             # everything
             self.scrolllines(self.selecteditemstartline)
             self.stdscr.clear()
             self.stdscr.refresh()
 
     def main(self, stdscr):
         """
         method to be wrapped by curses.wrapper() for selecting chunks.
         """
 
         origsigwinch = sentinel = object()
         if util.safehasattr(signal, 'SIGWINCH'):
             origsigwinch = signal.signal(signal.SIGWINCH,
                                          self.sigwinchhandler)
         try:
             return self._main(stdscr)
         finally:
             if origsigwinch is not sentinel:
                 signal.signal(signal.SIGWINCH, origsigwinch)
 
     def _main(self, stdscr):
         self.stdscr = stdscr
         # error during initialization, cannot be printed in the curses
         # interface, it should be printed by the calling code
         self.initexc = None
         self.yscreensize, self.xscreensize = self.stdscr.getmaxyx()
 
         curses.start_color()
         try:
             curses.use_default_colors()
         except curses.error:
             self.usecolor = False
 
         # In some situations we may have some cruft left on the "alternate
         # screen" from another program (or previous iterations of ourself), and
         # we won't clear it if the scroll region is small enough to comfortably
         # fit on the terminal.
         self.stdscr.clear()
 
         # don't display the cursor
         try:
             curses.curs_set(0)
         except curses.error:
             pass
 
         # available colors: black, blue, cyan, green, magenta, white, yellow
         # init_pair(color_id, foreground_color, background_color)
         self.initcolorpair(None, None, name="normal")
         self.initcolorpair(curses.COLOR_WHITE, curses.COLOR_MAGENTA,
                            name="selected")
         self.initcolorpair(curses.COLOR_RED, None, name="deletion")
         self.initcolorpair(curses.COLOR_GREEN, None, name="addition")
         self.initcolorpair(curses.COLOR_WHITE, curses.COLOR_BLUE, name="legend")
         # newwin([height, width,] begin_y, begin_x)
         self.statuswin = curses.newwin(self.numstatuslines, 0, 0, 0)
         self.statuswin.keypad(1) # interpret arrow-key, etc. esc sequences
 
         # figure out how much space to allocate for the chunk-pad which is
         # used for displaying the patch
 
         # stupid hack to prevent getnumlinesdisplayed from failing
         self.chunkpad = curses.newpad(1, self.xscreensize)
 
         # add 1 so to account for last line text reaching end of line
         self.numpadlines = self.getnumlinesdisplayed(ignorefolding=True) + 1
 
         try:
             self.chunkpad = curses.newpad(self.numpadlines, self.xscreensize)
         except curses.error:
             self.initexc = fallbackerror(
                 _('this diff is too large to be displayed'))
             return
         # initialize selecteditemendline (initial start-line is 0)
         self.selecteditemendline = self.getnumlinesdisplayed(
             self.currentselecteditem, recursechildren=False)
 
         while True:
             self.updatescreen()
             try:
                 with self.ui.timeblockedsection('crecord'):
                     keypressed = self.statuswin.getkey()
                 if self.errorstr is not None:
                     self.errorstr = None
                     continue
             except curses.error:
                 keypressed = "foobar"
             if self.handlekeypressed(keypressed):
                 break
 
         if self.commenttext != "":
             whitespaceremoved = re.sub(br"(?m)^\s.*(\n|$)", b"",
                                        self.commenttext)
             if whitespaceremoved != "":
                 self.opts['message'] = self.commenttext