help: document requirements

We didn't have unified documentation of the various repository
requirements. This patch changes that.

mercurial/help/internals/requirements.txt

@@ -0,0 +1,110 b''
+Requirements
+============
+
+Repositories contain a file (``.hg/requires``) containing a list of
+features/capabilities that are *required* for clients to interface
+with the repository. This file has been present in Mercurial since
+version 0.9.2 (released December 2006).
+
+One of the first things clients do when opening a repository is read
+``.hg/requires`` and verify that all listed requirements are supported,
+aborting if not. Requirements are therefore a strong mechanism to
+prevent incompatible clients from reading from unknown repository
+formats or even corrupting them by writing to them.
+
+Extensions may add requirements. When they do this, clients not running
+an extension will be unable to read from repositories.
+
+The following sections describe the requirements defined by the
+Mercurial core distribution.
+
+revlogv1
+--------
+
+When present, revlogs are version 1 (RevlogNG). RevlogNG was introduced
+in 2006. The ``revlogv1`` requirement has been enabled by default
+since the ``requires`` file was introduced in Mercurial 0.9.2.
+
+If this requirement is not present, version 0 revlogs are assumed.
+
+store
+-----
+
+The *store* repository layout should be used.
+
+This requirement has been enabled by default since the ``requires`` file
+was introduced in Mercurial 0.9.2.
+
+fncache
+-------
+
+The *fncache* repository layout should be used.
+
+The *fncache* layout hash encodes filenames with long paths and
+encodes reserved filenames.
+
+This requirement is enabled by default when the *store* requirement is
+enabled (which is the default behavior). It was introduced in Mercurial
+1.1 (released December 2008).
+
+shared
+------
+
+Denotes that the store for a repository is shared from another location
+(defined by the ``.hg/sharedpath`` file).
+
+This requirement is set when a repository is created via :hg:`share`.
+
+The requirement was added in Mercurial 1.3 (released July 2009).
+
+dotencode
+---------
+
+The *dotencode* repository layout should be used.
+
+The *dotencode* layout encodes the first period or space in filenames
+to prevent issues on OS X and Windows.
+
+This requirement is enabled by default when the *store* requirement
+is enabled (which is the default behavior). It was introduced in
+Mercurial 1.7 (released November 2010).
+
+parentdelta
+-----------
+
+Denotes a revlog delta encoding format that was experimental and
+replaced by *generaldelta*. It should not be seen in the wild because
+it was never enabled by default.
+
+This requirement was added in Mercurial 1.7 and removed in Mercurial
+1.9.
+
+generaldelta
+------------
+
+Revlogs should be created with the *generaldelta* flag enabled. The
+generaldelta flag will cause deltas to be encoded against a parent
+revision instead of the previous revision in the revlog.
+
+Support for this requirement was added in Mercurial 1.9 (released
+July 2011). The requirement was disabled on new repositories by
+default until Mercurial 3.7 (released February 2016).
+
+manifestv2
+----------
+
+Denotes that version 2 of manifests are being used.
+
+Support for this requirement was added in Mercurial 3.4 (released
+May 2015). The requirement is currently experimental and is disabled
+by default.
+
+treemanifest
+------------
+
+Denotes that tree manifests are being used. Tree manifests are
+one manifest per directory (as opposed to a single flat manifest).
+
+Support for this requirement was added in Mercurial 3.4 (released
+August 2015). The requirement is currently experimental and is
+disabled by default.

contrib/wix/help.wxs

@@ -1,51 +1,52 b''
 <?xml version="1.0" encoding="utf-8"?>
 <Wix xmlns="http://schemas.microsoft.com/wix/2006/wi">
 
   <?include guids.wxi ?>
   <?include defines.wxi ?>
 
   <Fragment>
     <ComponentGroup Id='helpFolder'>
       <ComponentRef Id='help.root' />
       <ComponentRef Id='help.internals' />
     </ComponentGroup>
   </Fragment>
 
   <Fragment>
     <DirectoryRef Id="INSTALLDIR">
       <Directory Id="helpdir" Name="help" FileSource="$(var.SourceDir)">
         <Component Id="help.root" Guid="$(var.help.root.guid)" Win64='$(var.IsX64)'>
           <File Name="config.txt" KeyPath="yes" />
           <File Name="dates.txt" />
           <File Name="diffs.txt" />
           <File Name="environment.txt" />
           <File Name="extensions.txt" />
           <File Name="filesets.txt" />
           <File Name="glossary.txt" />
           <File Name="hgignore.txt" />
           <File Name="hgweb.txt" />
           <File Name="merge-tools.txt" />
           <File Name="multirevs.txt" />
           <File Name="patterns.txt" />
           <File Name="phases.txt" />
           <File Name="revisions.txt" />
           <File Name="revsets.txt" />
           <File Name="scripting.txt" />
           <File Name="subrepos.txt" />
           <File Name="templates.txt" />
           <File Name="urls.txt" />
         </Component>
 
         <Directory Id="help.internaldir" Name="internals">
           <Component Id="help.internals" Guid="$(var.help.internals.guid)" Win64='$(var.IsX64)'>
             <File Id="internals.bundles.txt"      Name="bundles.txt" KeyPath="yes" />
             <File Id="internals.changegroups.txt" Name="changegroups.txt" />
+            <File Id="internals.requirements.txt" Name="requirements.txt" />
             <File Id="internals.revlogs.txt"      Name="revlogs.txt" />
           </Component>
         </Directory>
 
       </Directory>
     </DirectoryRef>
   </Fragment>
 
 </Wix>

mercurial/help.py

@@ -1,602 +1,604 b''
 # help.py - help data for mercurial
 #
 # Copyright 2006 Matt Mackall <[e-mail]>
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 from __future__ import absolute_import
 
 import itertools
 import os
 import textwrap
 
 from .i18n import (
     _,
     gettext,
 )
 from . import (
     cmdutil,
     encoding,
     error,
     extensions,
     filemerge,
     fileset,
     minirst,
     revset,
     templatefilters,
     templatekw,
     templater,
     util,
 )
 from .hgweb import (
     webcommands,
 )
 
 _exclkeywords = [
     "(DEPRECATED)",
     "(EXPERIMENTAL)",
     # i18n: "(DEPRECATED)" is a keyword, must be translated consistently
     _("(DEPRECATED)"),
     # i18n: "(EXPERIMENTAL)" is a keyword, must be translated consistently
     _("(EXPERIMENTAL)"),
     ]
 
 def listexts(header, exts, indent=1, showdeprecated=False):
     '''return a text listing of the given extensions'''
     rst = []
     if exts:
         for name, desc in sorted(exts.iteritems()):
             if not showdeprecated and any(w in desc for w in _exclkeywords):
                 continue
             rst.append('%s:%s: %s\n' % (' ' * indent, name, desc))
     if rst:
         rst.insert(0, '\n%s\n\n' % header)
     return rst
 
 def extshelp(ui):
     rst = loaddoc('extensions')(ui).splitlines(True)
     rst.extend(listexts(
         _('enabled extensions:'), extensions.enabled(), showdeprecated=True))
     rst.extend(listexts(_('disabled extensions:'), extensions.disabled()))
     doc = ''.join(rst)
     return doc
 
 def optrst(header, options, verbose):
     data = []
     multioccur = False
     for option in options:
         if len(option) == 5:
             shortopt, longopt, default, desc, optlabel = option
         else:
             shortopt, longopt, default, desc = option
             optlabel = _("VALUE") # default label
 
         if not verbose and any(w in desc for w in _exclkeywords):
             continue
 
         so = ''
         if shortopt:
             so = '-' + shortopt
         lo = '--' + longopt
         if default:
             desc += _(" (default: %s)") % default
 
         if isinstance(default, list):
             lo += " %s [+]" % optlabel
             multioccur = True
         elif (default is not None) and not isinstance(default, bool):
             lo += " %s" % optlabel
 
         data.append((so, lo, desc))
 
     if multioccur:
         header += (_(" ([+] can be repeated)"))
 
     rst = ['\n%s:\n\n' % header]
     rst.extend(minirst.maketable(data, 1))
 
     return ''.join(rst)
 
 def indicateomitted(rst, omitted, notomitted=None):
     rst.append('\n\n.. container:: omitted\n\n    %s\n\n' % omitted)
     if notomitted:
         rst.append('\n\n.. container:: notomitted\n\n    %s\n\n' % notomitted)
 
 def filtercmd(ui, cmd, kw, doc):
     if not ui.debugflag and cmd.startswith("debug") and kw != "debug":
         return True
     if not ui.verbose and doc and any(w in doc for w in _exclkeywords):
         return True
     return False
 
 def topicmatch(ui, kw):
     """Return help topics matching kw.
 
     Returns {'section': [(name, summary), ...], ...} where section is
     one of topics, commands, extensions, or extensioncommands.
     """
     kw = encoding.lower(kw)
     def lowercontains(container):
         return kw in encoding.lower(container)  # translated in helptable
     results = {'topics': [],
                'commands': [],
                'extensions': [],
                'extensioncommands': [],
                }
     for names, header, doc in helptable:
         # Old extensions may use a str as doc.
         if (sum(map(lowercontains, names))
             or lowercontains(header)
             or (callable(doc) and lowercontains(doc(ui)))):
             results['topics'].append((names[0], header))
     from . import commands # avoid cycle
     for cmd, entry in commands.table.iteritems():
         if len(entry) == 3:
             summary = entry[2]
         else:
             summary = ''
         # translate docs *before* searching there
         docs = _(getattr(entry[0], '__doc__', None)) or ''
         if kw in cmd or lowercontains(summary) or lowercontains(docs):
             doclines = docs.splitlines()
             if doclines:
                 summary = doclines[0]
             cmdname = cmd.partition('|')[0].lstrip('^')
             if filtercmd(ui, cmdname, kw, docs):
                 continue
             results['commands'].append((cmdname, summary))
     for name, docs in itertools.chain(
         extensions.enabled(False).iteritems(),
         extensions.disabled().iteritems()):
         if not docs:
             continue
         mod = extensions.load(ui, name, '')
         name = name.rpartition('.')[-1]
         if lowercontains(name) or lowercontains(docs):
             # extension docs are already translated
             results['extensions'].append((name, docs.splitlines()[0]))
         for cmd, entry in getattr(mod, 'cmdtable', {}).iteritems():
             if kw in cmd or (len(entry) > 2 and lowercontains(entry[2])):
                 cmdname = cmd.partition('|')[0].lstrip('^')
                 if entry[0].__doc__:
                     cmddoc = gettext(entry[0].__doc__).splitlines()[0]
                 else:
                     cmddoc = _('(no help text available)')
                 if filtercmd(ui, cmdname, kw, cmddoc):
                     continue
                 results['extensioncommands'].append((cmdname, cmddoc))
     return results
 
 def loaddoc(topic, subdir=None):
     """Return a delayed loader for help/topic.txt."""
 
     def loader(ui):
         docdir = os.path.join(util.datapath, 'help')
         if subdir:
             docdir = os.path.join(docdir, subdir)
         path = os.path.join(docdir, topic + ".txt")
         doc = gettext(util.readfile(path))
         for rewriter in helphooks.get(topic, []):
             doc = rewriter(ui, topic, doc)
         return doc
 
     return loader
 
 internalstable = sorted([
     (['bundles'], _('container for exchange of repository data'),
      loaddoc('bundles', subdir='internals')),
     (['changegroups'], _('representation of revlog data'),
      loaddoc('changegroups', subdir='internals')),
+    (['requirements'], _('repository requirements'),
+     loaddoc('requirements', subdir='internals')),
     (['revlogs'], _('revision storage mechanism'),
      loaddoc('revlogs', subdir='internals')),
 ])
 
 def internalshelp(ui):
     """Generate the index for the "internals" topic."""
     lines = []
     for names, header, doc in internalstable:
         lines.append(' :%s: %s\n' % (names[0], header))
 
     return ''.join(lines)
 
 helptable = sorted([
     (["config", "hgrc"], _("Configuration Files"), loaddoc('config')),
     (["dates"], _("Date Formats"), loaddoc('dates')),
     (["patterns"], _("File Name Patterns"), loaddoc('patterns')),
     (['environment', 'env'], _('Environment Variables'),
      loaddoc('environment')),
     (['revisions', 'revs'], _('Specifying Single Revisions'),
      loaddoc('revisions')),
     (['multirevs', 'mrevs'], _('Specifying Multiple Revisions'),
      loaddoc('multirevs')),
     (['revsets', 'revset'], _("Specifying Revision Sets"), loaddoc('revsets')),
     (['filesets', 'fileset'], _("Specifying File Sets"), loaddoc('filesets')),
     (['diffs'], _('Diff Formats'), loaddoc('diffs')),
     (['merge-tools', 'mergetools'], _('Merge Tools'), loaddoc('merge-tools')),
     (['templating', 'templates', 'template', 'style'], _('Template Usage'),
      loaddoc('templates')),
     (['urls'], _('URL Paths'), loaddoc('urls')),
     (["extensions"], _("Using Additional Features"), extshelp),
     (["subrepos", "subrepo"], _("Subrepositories"), loaddoc('subrepos')),
     (["hgweb"], _("Configuring hgweb"), loaddoc('hgweb')),
     (["glossary"], _("Glossary"), loaddoc('glossary')),
     (["hgignore", "ignore"], _("Syntax for Mercurial Ignore Files"),
      loaddoc('hgignore')),
     (["phases"], _("Working with Phases"), loaddoc('phases')),
     (['scripting'], _('Using Mercurial from scripts and automation'),
      loaddoc('scripting')),
     (['internals'], _("Technical implementation topics"),
      internalshelp),
 ])
 
 # Maps topics with sub-topics to a list of their sub-topics.
 subtopics = {
     'internals': internalstable,
 }
 
 # Map topics to lists of callable taking the current topic help and
 # returning the updated version
 helphooks = {}
 
 def addtopichook(topic, rewriter):
     helphooks.setdefault(topic, []).append(rewriter)
 
 def makeitemsdoc(ui, topic, doc, marker, items, dedent=False):
     """Extract docstring from the items key to function mapping, build a
     single documentation block and use it to overwrite the marker in doc.
     """
     entries = []
     for name in sorted(items):
         text = (items[name].__doc__ or '').rstrip()
         if (not text
             or not ui.verbose and any(w in text for w in _exclkeywords)):
             continue
         text = gettext(text)
         if dedent:
             text = textwrap.dedent(text)
         lines = text.splitlines()
         doclines = [(lines[0])]
         for l in lines[1:]:
             # Stop once we find some Python doctest
             if l.strip().startswith('>>>'):
                 break
             if dedent:
                 doclines.append(l.rstrip())
             else:
                 doclines.append('  ' + l.strip())
         entries.append('\n'.join(doclines))
     entries = '\n\n'.join(entries)
     return doc.replace(marker, entries)
 
 def addtopicsymbols(topic, marker, symbols, dedent=False):
     def add(ui, topic, doc):
         return makeitemsdoc(ui, topic, doc, marker, symbols, dedent=dedent)
     addtopichook(topic, add)
 
 addtopicsymbols('filesets', '.. predicatesmarker', fileset.symbols)
 addtopicsymbols('merge-tools', '.. internaltoolsmarker',
                 filemerge.internalsdoc)
 addtopicsymbols('revsets', '.. predicatesmarker', revset.symbols)
 addtopicsymbols('templates', '.. keywordsmarker', templatekw.keywords)
 addtopicsymbols('templates', '.. filtersmarker', templatefilters.filters)
 addtopicsymbols('templates', '.. functionsmarker', templater.funcs)
 addtopicsymbols('hgweb', '.. webcommandsmarker', webcommands.commands,
                 dedent=True)
 
 def help_(ui, name, unknowncmd=False, full=True, subtopic=None, **opts):
     '''
     Generate the help for 'name' as unformatted restructured text. If
     'name' is None, describe the commands available.
     '''
 
     from . import commands # avoid cycle
 
     def helpcmd(name, subtopic=None):
         try:
             aliases, entry = cmdutil.findcmd(name, commands.table,
                                              strict=unknowncmd)
         except error.AmbiguousCommand as inst:
             # py3k fix: except vars can't be used outside the scope of the
             # except block, nor can be used inside a lambda. python issue4617
             prefix = inst.args[0]
             select = lambda c: c.lstrip('^').startswith(prefix)
             rst = helplist(select)
             return rst
 
         rst = []
 
         # check if it's an invalid alias and display its error if it is
         if getattr(entry[0], 'badalias', None):
             rst.append(entry[0].badalias + '\n')
             if entry[0].unknowncmd:
                 try:
                     rst.extend(helpextcmd(entry[0].cmdname))
                 except error.UnknownCommand:
                     pass
             return rst
 
         # synopsis
         if len(entry) > 2:
             if entry[2].startswith('hg'):
                 rst.append("%s\n" % entry[2])
             else:
                 rst.append('hg %s %s\n' % (aliases[0], entry[2]))
         else:
             rst.append('hg %s\n' % aliases[0])
         # aliases
         if full and not ui.quiet and len(aliases) > 1:
             rst.append(_("\naliases: %s\n") % ', '.join(aliases[1:]))
         rst.append('\n')
 
         # description
         doc = gettext(entry[0].__doc__)
         if not doc:
             doc = _("(no help text available)")
         if util.safehasattr(entry[0], 'definition'):  # aliased command
             if entry[0].definition.startswith('!'):  # shell alias
                 doc = _('shell alias for::\n\n    %s') % entry[0].definition[1:]
             else:
                 doc = _('alias for: hg %s\n\n%s') % (entry[0].definition, doc)
         doc = doc.splitlines(True)
         if ui.quiet or not full:
             rst.append(doc[0])
         else:
             rst.extend(doc)
         rst.append('\n')
 
         # check if this command shadows a non-trivial (multi-line)
         # extension help text
         try:
             mod = extensions.find(name)
             doc = gettext(mod.__doc__) or ''
             if '\n' in doc.strip():
                 msg = _('(use "hg help -e %s" to show help for '
                         'the %s extension)') % (name, name)
                 rst.append('\n%s\n' % msg)
         except KeyError:
             pass
 
         # options
         if not ui.quiet and entry[1]:
             rst.append(optrst(_("options"), entry[1], ui.verbose))
 
         if ui.verbose:
             rst.append(optrst(_("global options"),
                               commands.globalopts, ui.verbose))
 
         if not ui.verbose:
             if not full:
                 rst.append(_('\n(use "hg %s -h" to show more help)\n')
                            % name)
             elif not ui.quiet:
                 rst.append(_('\n(some details hidden, use --verbose '
                                'to show complete help)'))
 
         return rst
 
 
     def helplist(select=None, **opts):
         # list of commands
         if name == "shortlist":
             header = _('basic commands:\n\n')
         elif name == "debug":
             header = _('debug commands (internal and unsupported):\n\n')
         else:
             header = _('list of commands:\n\n')
 
         h = {}
         cmds = {}
         for c, e in commands.table.iteritems():
             f = c.partition("|")[0]
             if select and not select(f):
                 continue
             if (not select and name != 'shortlist' and
                 e[0].__module__ != commands.__name__):
                 continue
             if name == "shortlist" and not f.startswith("^"):
                 continue
             f = f.lstrip("^")
             doc = e[0].__doc__
             if filtercmd(ui, f, name, doc):
                 continue
             doc = gettext(doc)
             if not doc:
                 doc = _("(no help text available)")
             h[f] = doc.splitlines()[0].rstrip()
             cmds[f] = c.lstrip("^")
 
         rst = []
         if not h:
             if not ui.quiet:
                 rst.append(_('no commands defined\n'))
             return rst
 
         if not ui.quiet:
             rst.append(header)
         fns = sorted(h)
         for f in fns:
             if ui.verbose:
                 commacmds = cmds[f].replace("|",", ")
                 rst.append(" :%s: %s\n" % (commacmds, h[f]))
             else:
                 rst.append(' :%s: %s\n' % (f, h[f]))
 
         ex = opts.get
         anyopts = (ex('keyword') or not (ex('command') or ex('extension')))
         if not name and anyopts:
             exts = listexts(_('enabled extensions:'), extensions.enabled())
             if exts:
                 rst.append('\n')
                 rst.extend(exts)
 
             rst.append(_("\nadditional help topics:\n\n"))
             topics = []
             for names, header, doc in helptable:
                 topics.append((names[0], header))
             for t, desc in topics:
                 rst.append(" :%s: %s\n" % (t, desc))
 
         if ui.quiet:
             pass
         elif ui.verbose:
             rst.append('\n%s\n' % optrst(_("global options"),
                                          commands.globalopts, ui.verbose))
             if name == 'shortlist':
                 rst.append(_('\n(use "hg help" for the full list '
                              'of commands)\n'))
         else:
             if name == 'shortlist':
                 rst.append(_('\n(use "hg help" for the full list of commands '
                              'or "hg -v" for details)\n'))
             elif name and not full:
                 rst.append(_('\n(use "hg help %s" to show the full help '
                              'text)\n') % name)
             elif name and cmds and name in cmds.keys():
                 rst.append(_('\n(use "hg help -v -e %s" to show built-in '
                              'aliases and global options)\n') % name)
             else:
                 rst.append(_('\n(use "hg help -v%s" to show built-in aliases '
                              'and global options)\n')
                            % (name and " " + name or ""))
         return rst
 
     def helptopic(name, subtopic=None):
         # Look for sub-topic entry first.
         header, doc = None, None
         if subtopic and name in subtopics:
             for names, header, doc in subtopics[name]:
                 if subtopic in names:
                     break
 
         if not header:
             for names, header, doc in helptable:
                 if name in names:
                     break
             else:
                 raise error.UnknownCommand(name)
 
         rst = [minirst.section(header)]
 
         # description
         if not doc:
             rst.append("    %s\n" % _("(no help text available)"))
         if callable(doc):
             rst += ["    %s\n" % l for l in doc(ui).splitlines()]
 
         if not ui.verbose:
             omitted = _('(some details hidden, use --verbose'
                          ' to show complete help)')
             indicateomitted(rst, omitted)
 
         try:
             cmdutil.findcmd(name, commands.table)
             rst.append(_('\nuse "hg help -c %s" to see help for '
                        'the %s command\n') % (name, name))
         except error.UnknownCommand:
             pass
         return rst
 
     def helpext(name, subtopic=None):
         try:
             mod = extensions.find(name)
             doc = gettext(mod.__doc__) or _('no help text available')
         except KeyError:
             mod = None
             doc = extensions.disabledext(name)
             if not doc:
                 raise error.UnknownCommand(name)
 
         if '\n' not in doc:
             head, tail = doc, ""
         else:
             head, tail = doc.split('\n', 1)
         rst = [_('%s extension - %s\n\n') % (name.rpartition('.')[-1], head)]
         if tail:
             rst.extend(tail.splitlines(True))
             rst.append('\n')
 
         if not ui.verbose:
             omitted = _('(some details hidden, use --verbose'
                          ' to show complete help)')
             indicateomitted(rst, omitted)
 
         if mod:
             try:
                 ct = mod.cmdtable
             except AttributeError:
                 ct = {}
             modcmds = set([c.partition('|')[0] for c in ct])
             rst.extend(helplist(modcmds.__contains__))
         else:
             rst.append(_('(use "hg help extensions" for information on enabling'
                        ' extensions)\n'))
         return rst
 
     def helpextcmd(name, subtopic=None):
         cmd, ext, mod = extensions.disabledcmd(ui, name,
                                                ui.configbool('ui', 'strict'))
         doc = gettext(mod.__doc__).splitlines()[0]
 
         rst = listexts(_("'%s' is provided by the following "
                               "extension:") % cmd, {ext: doc}, indent=4,
                        showdeprecated=True)
         rst.append('\n')
         rst.append(_('(use "hg help extensions" for information on enabling '
                    'extensions)\n'))
         return rst
 
 
     rst = []
     kw = opts.get('keyword')
     if kw or name is None and any(opts[o] for o in opts):
         matches = topicmatch(ui, name or '')
         helpareas = []
         if opts.get('extension'):
             helpareas += [('extensions', _('Extensions'))]
         if opts.get('command'):
             helpareas += [('commands', _('Commands'))]
         if not helpareas:
             helpareas = [('topics', _('Topics')),
                          ('commands', _('Commands')),
                          ('extensions', _('Extensions')),
                          ('extensioncommands', _('Extension Commands'))]
         for t, title in helpareas:
             if matches[t]:
                 rst.append('%s:\n\n' % title)
                 rst.extend(minirst.maketable(sorted(matches[t]), 1))
                 rst.append('\n')
         if not rst:
             msg = _('no matches')
             hint = _('try "hg help" for a list of topics')
             raise error.Abort(msg, hint=hint)
     elif name and name != 'shortlist':
         queries = []
         if unknowncmd:
             queries += [helpextcmd]
         if opts.get('extension'):
             queries += [helpext]
         if opts.get('command'):
             queries += [helpcmd]
         if not queries:
             queries = (helptopic, helpcmd, helpext, helpextcmd)
         for f in queries:
             try:
                 rst = f(name, subtopic)
                 break
             except error.UnknownCommand:
                 pass
         else:
             if unknowncmd:
                 raise error.UnknownCommand(name)
             else:
                 msg = _('no such help topic: %s') % name
                 hint = _('try "hg help --keyword %s"') % name
                 raise error.Abort(msg, hint=hint)
     else:
         # program name
         if not ui.quiet:
             rst = [_("Mercurial Distributed SCM\n"), '\n']
         rst.extend(helplist(None, **opts))
 
     return ''.join(rst)

tests/test-help.t

@@ -1,2994 +1,3002 b''
 Short help:
 
   $ hg
   Mercurial Distributed SCM
   
   basic commands:
   
    add           add the specified files on the next commit
    annotate      show changeset information by line for each file
    clone         make a copy of an existing repository
    commit        commit the specified files or all outstanding changes
    diff          diff repository (or selected files)
    export        dump the header and diffs for one or more changesets
    forget        forget the specified files on the next commit
    init          create a new repository in the given directory
    log           show revision history of entire repository or files
    merge         merge another revision into working directory
    pull          pull changes from the specified source
    push          push changes to the specified destination
    remove        remove the specified files on the next commit
    serve         start stand-alone webserver
    status        show changed files in the working directory
    summary       summarize working directory state
    update        update working directory (or switch revisions)
   
   (use "hg help" for the full list of commands or "hg -v" for details)
 
   $ hg -q
    add           add the specified files on the next commit
    annotate      show changeset information by line for each file
    clone         make a copy of an existing repository
    commit        commit the specified files or all outstanding changes
    diff          diff repository (or selected files)
    export        dump the header and diffs for one or more changesets
    forget        forget the specified files on the next commit
    init          create a new repository in the given directory
    log           show revision history of entire repository or files
    merge         merge another revision into working directory
    pull          pull changes from the specified source
    push          push changes to the specified destination
    remove        remove the specified files on the next commit
    serve         start stand-alone webserver
    status        show changed files in the working directory
    summary       summarize working directory state
    update        update working directory (or switch revisions)
 
   $ hg help
   Mercurial Distributed SCM
   
   list of commands:
   
    add           add the specified files on the next commit
    addremove     add all new files, delete all missing files
    annotate      show changeset information by line for each file
    archive       create an unversioned archive of a repository revision
    backout       reverse effect of earlier changeset
    bisect        subdivision search of changesets
    bookmarks     create a new bookmark or list existing bookmarks
    branch        set or show the current branch name
    branches      list repository named branches
    bundle        create a changegroup file
    cat           output the current or given revision of files
    clone         make a copy of an existing repository
    commit        commit the specified files or all outstanding changes
    config        show combined config settings from all hgrc files
    copy          mark files as copied for the next commit
    diff          diff repository (or selected files)
    export        dump the header and diffs for one or more changesets
    files         list tracked files
    forget        forget the specified files on the next commit
    graft         copy changes from other branches onto the current branch
    grep          search for a pattern in specified files and revisions
    heads         show branch heads
    help          show help for a given topic or a help overview
    identify      identify the working directory or specified revision
    import        import an ordered set of patches
    incoming      show new changesets found in source
    init          create a new repository in the given directory
    log           show revision history of entire repository or files
    manifest      output the current or given revision of the project manifest
    merge         merge another revision into working directory
    outgoing      show changesets not found in the destination
    paths         show aliases for remote repositories
    phase         set or show the current phase name
    pull          pull changes from the specified source
    push          push changes to the specified destination
    recover       roll back an interrupted transaction
    remove        remove the specified files on the next commit
    rename        rename files; equivalent of copy + remove
    resolve       redo merges or set/view the merge status of files
    revert        restore files to their checkout state
    root          print the root (top) of the current working directory
    serve         start stand-alone webserver
    status        show changed files in the working directory
    summary       summarize working directory state
    tag           add one or more tags for the current or given revision
    tags          list repository tags
    unbundle      apply one or more changegroup files
    update        update working directory (or switch revisions)
    verify        verify the integrity of the repository
    version       output version and copyright information
   
   additional help topics:
   
    config        Configuration Files
    dates         Date Formats
    diffs         Diff Formats
    environment   Environment Variables
    extensions    Using Additional Features
    filesets      Specifying File Sets
    glossary      Glossary
    hgignore      Syntax for Mercurial Ignore Files
    hgweb         Configuring hgweb
    internals     Technical implementation topics
    merge-tools   Merge Tools
    multirevs     Specifying Multiple Revisions
    patterns      File Name Patterns
    phases        Working with Phases
    revisions     Specifying Single Revisions
    revsets       Specifying Revision Sets
    scripting     Using Mercurial from scripts and automation
    subrepos      Subrepositories
    templating    Template Usage
    urls          URL Paths
   
   (use "hg help -v" to show built-in aliases and global options)
 
   $ hg -q help
    add           add the specified files on the next commit
    addremove     add all new files, delete all missing files
    annotate      show changeset information by line for each file
    archive       create an unversioned archive of a repository revision
    backout       reverse effect of earlier changeset
    bisect        subdivision search of changesets
    bookmarks     create a new bookmark or list existing bookmarks
    branch        set or show the current branch name
    branches      list repository named branches
    bundle        create a changegroup file
    cat           output the current or given revision of files
    clone         make a copy of an existing repository
    commit        commit the specified files or all outstanding changes
    config        show combined config settings from all hgrc files
    copy          mark files as copied for the next commit
    diff          diff repository (or selected files)
    export        dump the header and diffs for one or more changesets
    files         list tracked files
    forget        forget the specified files on the next commit
    graft         copy changes from other branches onto the current branch
    grep          search for a pattern in specified files and revisions
    heads         show branch heads
    help          show help for a given topic or a help overview
    identify      identify the working directory or specified revision
    import        import an ordered set of patches
    incoming      show new changesets found in source
    init          create a new repository in the given directory
    log           show revision history of entire repository or files
    manifest      output the current or given revision of the project manifest
    merge         merge another revision into working directory
    outgoing      show changesets not found in the destination
    paths         show aliases for remote repositories
    phase         set or show the current phase name
    pull          pull changes from the specified source
    push          push changes to the specified destination
    recover       roll back an interrupted transaction
    remove        remove the specified files on the next commit
    rename        rename files; equivalent of copy + remove
    resolve       redo merges or set/view the merge status of files
    revert        restore files to their checkout state
    root          print the root (top) of the current working directory
    serve         start stand-alone webserver
    status        show changed files in the working directory
    summary       summarize working directory state
    tag           add one or more tags for the current or given revision
    tags          list repository tags
    unbundle      apply one or more changegroup files
    update        update working directory (or switch revisions)
    verify        verify the integrity of the repository
    version       output version and copyright information
   
   additional help topics:
   
    config        Configuration Files
    dates         Date Formats
    diffs         Diff Formats
    environment   Environment Variables
    extensions    Using Additional Features
    filesets      Specifying File Sets
    glossary      Glossary
    hgignore      Syntax for Mercurial Ignore Files
    hgweb         Configuring hgweb
    internals     Technical implementation topics
    merge-tools   Merge Tools
    multirevs     Specifying Multiple Revisions
    patterns      File Name Patterns
    phases        Working with Phases
    revisions     Specifying Single Revisions
    revsets       Specifying Revision Sets
    scripting     Using Mercurial from scripts and automation
    subrepos      Subrepositories
    templating    Template Usage
    urls          URL Paths
 
 Test extension help:
   $ hg help extensions --config extensions.rebase= --config extensions.children=
   Using Additional Features
   """""""""""""""""""""""""
   
       Mercurial has the ability to add new features through the use of
       extensions. Extensions may add new commands, add options to existing
       commands, change the default behavior of commands, or implement hooks.
   
       To enable the "foo" extension, either shipped with Mercurial or in the
       Python search path, create an entry for it in your configuration file,
       like this:
   
         [extensions]
         foo =
   
       You may also specify the full path to an extension:
   
         [extensions]
         myfeature = ~/.hgext/myfeature.py
   
       See 'hg help config' for more information on configuration files.
   
       Extensions are not loaded by default for a variety of reasons: they can
       increase startup overhead; they may be meant for advanced usage only; they
       may provide potentially dangerous abilities (such as letting you destroy
       or modify history); they might not be ready for prime time; or they may
       alter some usual behaviors of stock Mercurial. It is thus up to the user
       to activate extensions as needed.
   
       To explicitly disable an extension enabled in a configuration file of
       broader scope, prepend its path with !:
   
         [extensions]
         # disabling extension bar residing in /path/to/extension/bar.py
         bar = !/path/to/extension/bar.py
         # ditto, but no path was supplied for extension baz
         baz = !
   
       enabled extensions:
   
        children      command to display child changesets (DEPRECATED)
        rebase        command to move sets of revisions to a different ancestor
   
       disabled extensions:
   
        acl           hooks for controlling repository access
        blackbox      log repository events to a blackbox for debugging
        bugzilla      hooks for integrating with the Bugzilla bug tracker
        censor        erase file content at a given revision
        churn         command to display statistics about repository history
        clonebundles  advertise pre-generated bundles to seed clones
        color         colorize output from some commands
        convert       import revisions from foreign VCS repositories into
                      Mercurial
        eol           automatically manage newlines in repository files
        extdiff       command to allow external programs to compare revisions
        factotum      http authentication with factotum
        gpg           commands to sign and verify changesets
        hgcia         hooks for integrating with the CIA.vc notification service
        hgk           browse the repository in a graphical way
        highlight     syntax highlighting for hgweb (requires Pygments)
        histedit      interactive history editing
        keyword       expand keywords in tracked files
        largefiles    track large binary files
        mq            manage a stack of patches
        notify        hooks for sending email push notifications
        pager         browse command output with an external pager
        patchbomb     command to send changesets as (a series of) patch emails
        purge         command to delete untracked files from the working
                      directory
        record        commands to interactively select changes for
                      commit/qrefresh
        relink        recreates hardlinks between repository clones
        schemes       extend schemes with shortcuts to repository swarms
        share         share a common history between several working directories
        shelve        save and restore changes to the working directory
        strip         strip changesets and their descendants from history
        transplant    command to transplant changesets from another branch
        win32mbcs     allow the use of MBCS paths with problematic encodings
        zeroconf      discover and advertise repositories on the local network
 
 Verify that extension keywords appear in help templates
 
   $ hg help --config extensions.transplant= templating|grep transplant > /dev/null
 
 Test short command list with verbose option
 
   $ hg -v help shortlist
   Mercurial Distributed SCM
   
   basic commands:
   
    add           add the specified files on the next commit
    annotate, blame
                  show changeset information by line for each file
    clone         make a copy of an existing repository
    commit, ci    commit the specified files or all outstanding changes
    diff          diff repository (or selected files)
    export        dump the header and diffs for one or more changesets
    forget        forget the specified files on the next commit
    init          create a new repository in the given directory
    log, history  show revision history of entire repository or files
    merge         merge another revision into working directory
    pull          pull changes from the specified source
    push          push changes to the specified destination
    remove, rm    remove the specified files on the next commit
    serve         start stand-alone webserver
    status, st    show changed files in the working directory
    summary, sum  summarize working directory state
    update, up, checkout, co
                  update working directory (or switch revisions)
   
   global options ([+] can be repeated):
   
    -R --repository REPO   repository root directory or name of overlay bundle
                           file
       --cwd DIR           change working directory
    -y --noninteractive    do not prompt, automatically pick the first choice for
                           all prompts
    -q --quiet             suppress output
    -v --verbose           enable additional output
       --config CONFIG [+] set/override config option (use 'section.name=value')
       --debug             enable debugging output
       --debugger          start debugger
       --encoding ENCODE   set the charset encoding (default: ascii)
       --encodingmode MODE set the charset encoding mode (default: strict)
       --traceback         always print a traceback on exception
       --time              time how long the command takes
       --profile           print command execution profile
       --version           output version information and exit
    -h --help              display help and exit
       --hidden            consider hidden changesets
   
   (use "hg help" for the full list of commands)
 
   $ hg add -h
   hg add [OPTION]... [FILE]...
   
   add the specified files on the next commit
   
       Schedule files to be version controlled and added to the repository.
   
       The files will be added to the repository at the next commit. To undo an
       add before that, see 'hg forget'.
   
       If no names are given, add all files to the repository (except files
       matching ".hgignore").
   
       Returns 0 if all files are successfully added.
   
   options ([+] can be repeated):
   
    -I --include PATTERN [+] include names matching the given patterns
    -X --exclude PATTERN [+] exclude names matching the given patterns
    -S --subrepos            recurse into subrepositories
    -n --dry-run             do not perform actions, just print output
   
   (some details hidden, use --verbose to show complete help)
 
 Verbose help for add
 
   $ hg add -hv
   hg add [OPTION]... [FILE]...
   
   add the specified files on the next commit
   
       Schedule files to be version controlled and added to the repository.
   
       The files will be added to the repository at the next commit. To undo an
       add before that, see 'hg forget'.
   
       If no names are given, add all files to the repository (except files
       matching ".hgignore").
   
       Examples:
   
         - New (unknown) files are added automatically by 'hg add':
   
             $ ls
             foo.c
             $ hg status
             ? foo.c
             $ hg add
             adding foo.c
             $ hg status
             A foo.c
   
         - Specific files to be added can be specified:
   
             $ ls
             bar.c  foo.c
             $ hg status
             ? bar.c
             ? foo.c
             $ hg add bar.c
             $ hg status
             A bar.c
             ? foo.c
   
       Returns 0 if all files are successfully added.
   
   options ([+] can be repeated):
   
    -I --include PATTERN [+] include names matching the given patterns
    -X --exclude PATTERN [+] exclude names matching the given patterns
    -S --subrepos            recurse into subrepositories
    -n --dry-run             do not perform actions, just print output
   
   global options ([+] can be repeated):
   
    -R --repository REPO   repository root directory or name of overlay bundle
                           file
       --cwd DIR           change working directory
    -y --noninteractive    do not prompt, automatically pick the first choice for
                           all prompts
    -q --quiet             suppress output
    -v --verbose           enable additional output
       --config CONFIG [+] set/override config option (use 'section.name=value')
       --debug             enable debugging output
       --debugger          start debugger
       --encoding ENCODE   set the charset encoding (default: ascii)
       --encodingmode MODE set the charset encoding mode (default: strict)
       --traceback         always print a traceback on exception
       --time              time how long the command takes
       --profile           print command execution profile
       --version           output version information and exit
    -h --help              display help and exit
       --hidden            consider hidden changesets
 
 Test help option with version option
 
   $ hg add -h --version
   Mercurial Distributed SCM (version *) (glob)
   (see https://mercurial-scm.org for more information)
   
   Copyright (C) 2005-2016 Matt Mackall and others
   This is free software; see the source for copying conditions. There is NO
   warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 
   $ hg add --skjdfks
   hg add: option --skjdfks not recognized
   hg add [OPTION]... [FILE]...
   
   add the specified files on the next commit
   
   options ([+] can be repeated):
   
    -I --include PATTERN [+] include names matching the given patterns
    -X --exclude PATTERN [+] exclude names matching the given patterns
    -S --subrepos            recurse into subrepositories
    -n --dry-run             do not perform actions, just print output
   
   (use "hg add -h" to show more help)
   [255]
 
 Test ambiguous command help
 
   $ hg help ad
   list of commands:
   
    add           add the specified files on the next commit
    addremove     add all new files, delete all missing files
   
   (use "hg help -v ad" to show built-in aliases and global options)
 
 Test command without options
 
   $ hg help verify
   hg verify
   
   verify the integrity of the repository
   
       Verify the integrity of the current repository.
   
       This will perform an extensive check of the repository's integrity,
       validating the hashes and checksums of each entry in the changelog,
       manifest, and tracked files, as well as the integrity of their crosslinks
       and indices.
   
       Please see https://mercurial-scm.org/wiki/RepositoryCorruption for more
       information about recovery from corruption of the repository.
   
       Returns 0 on success, 1 if errors are encountered.
   
   (some details hidden, use --verbose to show complete help)
 
   $ hg help diff
   hg diff [OPTION]... ([-c REV] | [-r REV1 [-r REV2]]) [FILE]...
   
   diff repository (or selected files)
   
       Show differences between revisions for the specified files.
   
       Differences between files are shown using the unified diff format.
   
       Note:
          'hg diff' may generate unexpected results for merges, as it will
          default to comparing against the working directory's first parent
          changeset if no revisions are specified.
   
       When two revision arguments are given, then changes are shown between
       those revisions. If only one revision is specified then that revision is
       compared to the working directory, and, when no revisions are specified,
       the working directory files are compared to its first parent.
   
       Alternatively you can specify -c/--change with a revision to see the
       changes in that changeset relative to its first parent.
   
       Without the -a/--text option, diff will avoid generating diffs of files it
       detects as binary. With -a, diff will generate a diff anyway, probably
       with undesirable results.
   
       Use the -g/--git option to generate diffs in the git extended diff format.
       For more information, read 'hg help diffs'.
   
       Returns 0 on success.
   
   options ([+] can be repeated):
   
    -r --rev REV [+]         revision
    -c --change REV          change made by revision
    -a --text                treat all files as text
    -g --git                 use git extended diff format
       --nodates             omit dates from diff headers
       --noprefix            omit a/ and b/ prefixes from filenames
    -p --show-function       show which function each change is in
       --reverse             produce a diff that undoes the changes
    -w --ignore-all-space    ignore white space when comparing lines
    -b --ignore-space-change ignore changes in the amount of white space
    -B --ignore-blank-lines  ignore changes whose lines are all blank
    -U --unified NUM         number of lines of context to show
       --stat                output diffstat-style summary of changes
       --root DIR            produce diffs relative to subdirectory
    -I --include PATTERN [+] include names matching the given patterns
    -X --exclude PATTERN [+] exclude names matching the given patterns
    -S --subrepos            recurse into subrepositories
   
   (some details hidden, use --verbose to show complete help)
 
   $ hg help status
   hg status [OPTION]... [FILE]...
   
   aliases: st
   
   show changed files in the working directory
   
       Show status of files in the repository. If names are given, only files
       that match are shown. Files that are clean or ignored or the source of a
       copy/move operation, are not listed unless -c/--clean, -i/--ignored,
       -C/--copies or -A/--all are given. Unless options described with "show
       only ..." are given, the options -mardu are used.
   
       Option -q/--quiet hides untracked (unknown and ignored) files unless
       explicitly requested with -u/--unknown or -i/--ignored.
   
       Note:
          'hg status' may appear to disagree with diff if permissions have
          changed or a merge has occurred. The standard diff format does not
          report permission changes and diff only reports changes relative to one
          merge parent.
   
       If one revision is given, it is used as the base revision. If two
       revisions are given, the differences between them are shown. The --change
       option can also be used as a shortcut to list the changed files of a
       revision from its first parent.
   
       The codes used to show the status of files are:
   
         M = modified
         A = added
         R = removed
         C = clean
         ! = missing (deleted by non-hg command, but still tracked)
         ? = not tracked
         I = ignored
           = origin of the previous file (with --copies)
   
       Returns 0 on success.
   
   options ([+] can be repeated):
   
    -A --all                 show status of all files
    -m --modified            show only modified files
    -a --added               show only added files
    -r --removed             show only removed files
    -d --deleted             show only deleted (but tracked) files
    -c --clean               show only files without changes
    -u --unknown             show only unknown (not tracked) files
    -i --ignored             show only ignored files
    -n --no-status           hide status prefix
    -C --copies              show source of copied files
    -0 --print0              end filenames with NUL, for use with xargs
       --rev REV [+]         show difference from revision
       --change REV          list the changed files of a revision
    -I --include PATTERN [+] include names matching the given patterns
    -X --exclude PATTERN [+] exclude names matching the given patterns
    -S --subrepos            recurse into subrepositories
   
   (some details hidden, use --verbose to show complete help)
 
   $ hg -q help status
   hg status [OPTION]... [FILE]...
   
   show changed files in the working directory
 
   $ hg help foo
   abort: no such help topic: foo
   (try "hg help --keyword foo")
   [255]
 
   $ hg skjdfks
   hg: unknown command 'skjdfks'
   Mercurial Distributed SCM
   
   basic commands:
   
    add           add the specified files on the next commit
    annotate      show changeset information by line for each file
    clone         make a copy of an existing repository
    commit        commit the specified files or all outstanding changes
    diff          diff repository (or selected files)
    export        dump the header and diffs for one or more changesets
    forget        forget the specified files on the next commit
    init          create a new repository in the given directory
    log           show revision history of entire repository or files
    merge         merge another revision into working directory
    pull          pull changes from the specified source
    push          push changes to the specified destination
    remove        remove the specified files on the next commit
    serve         start stand-alone webserver
    status        show changed files in the working directory
    summary       summarize working directory state
    update        update working directory (or switch revisions)
   
   (use "hg help" for the full list of commands or "hg -v" for details)
   [255]
 
 
 Make sure that we don't run afoul of the help system thinking that
 this is a section and erroring out weirdly.
 
   $ hg .log
   hg: unknown command '.log'
   (did you mean log?)
   [255]
 
   $ hg log.
   hg: unknown command 'log.'
   (did you mean log?)
   [255]
   $ hg pu.lh
   hg: unknown command 'pu.lh'
   (did you mean one of pull, push?)
   [255]
 
   $ cat > helpext.py <<EOF
   > import os
   > from mercurial import cmdutil, commands
   > 
   > cmdtable = {}
   > command = cmdutil.command(cmdtable)
   > 
   > @command('nohelp',
   >     [('', 'longdesc', 3, 'x'*90),
   >     ('n', '', None, 'normal desc'),
   >     ('', 'newline', '', 'line1\nline2')],
   >     'hg nohelp',
   >     norepo=True)
   > @command('debugoptDEP', [('', 'dopt', None, 'option is (DEPRECATED)')])
   > @command('debugoptEXP', [('', 'eopt', None, 'option is (EXPERIMENTAL)')])
   > def nohelp(ui, *args, **kwargs):
   >     pass
   > 
   > EOF
   $ echo '[extensions]' >> $HGRCPATH
   $ echo "helpext = `pwd`/helpext.py" >> $HGRCPATH
 
 Test command with no help text
 
   $ hg help nohelp
   hg nohelp
   
   (no help text available)
   
   options:
   
       --longdesc VALUE xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
                        xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx (default: 3)
    -n --               normal desc
       --newline VALUE  line1 line2
   
   (some details hidden, use --verbose to show complete help)
 
   $ hg help -k nohelp
   Commands:
   
    nohelp hg nohelp
   
   Extension Commands:
   
    nohelp (no help text available)
 
 Test that default list of commands omits extension commands
 
   $ hg help
   Mercurial Distributed SCM
   
   list of commands:
   
    add           add the specified files on the next commit
    addremove     add all new files, delete all missing files
    annotate      show changeset information by line for each file
    archive       create an unversioned archive of a repository revision
    backout       reverse effect of earlier changeset
    bisect        subdivision search of changesets
    bookmarks     create a new bookmark or list existing bookmarks
    branch        set or show the current branch name
    branches      list repository named branches
    bundle        create a changegroup file
    cat           output the current or given revision of files
    clone         make a copy of an existing repository
    commit        commit the specified files or all outstanding changes
    config        show combined config settings from all hgrc files
    copy          mark files as copied for the next commit
    diff          diff repository (or selected files)
    export        dump the header and diffs for one or more changesets
    files         list tracked files
    forget        forget the specified files on the next commit
    graft         copy changes from other branches onto the current branch
    grep          search for a pattern in specified files and revisions
    heads         show branch heads
    help          show help for a given topic or a help overview
    identify      identify the working directory or specified revision
    import        import an ordered set of patches
    incoming      show new changesets found in source
    init          create a new repository in the given directory
    log           show revision history of entire repository or files
    manifest      output the current or given revision of the project manifest
    merge         merge another revision into working directory
    outgoing      show changesets not found in the destination
    paths         show aliases for remote repositories
    phase         set or show the current phase name
    pull          pull changes from the specified source
    push          push changes to the specified destination
    recover       roll back an interrupted transaction
    remove        remove the specified files on the next commit
    rename        rename files; equivalent of copy + remove
    resolve       redo merges or set/view the merge status of files
    revert        restore files to their checkout state
    root          print the root (top) of the current working directory
    serve         start stand-alone webserver
    status        show changed files in the working directory
    summary       summarize working directory state
    tag           add one or more tags for the current or given revision
    tags          list repository tags
    unbundle      apply one or more changegroup files
    update        update working directory (or switch revisions)
    verify        verify the integrity of the repository
    version       output version and copyright information
   
   enabled extensions:
   
    helpext       (no help text available)
   
   additional help topics:
   
    config        Configuration Files
    dates         Date Formats
    diffs         Diff Formats
    environment   Environment Variables
    extensions    Using Additional Features
    filesets      Specifying File Sets
    glossary      Glossary
    hgignore      Syntax for Mercurial Ignore Files
    hgweb         Configuring hgweb
    internals     Technical implementation topics
    merge-tools   Merge Tools
    multirevs     Specifying Multiple Revisions
    patterns      File Name Patterns
    phases        Working with Phases
    revisions     Specifying Single Revisions
    revsets       Specifying Revision Sets
    scripting     Using Mercurial from scripts and automation
    subrepos      Subrepositories
    templating    Template Usage
    urls          URL Paths
   
   (use "hg help -v" to show built-in aliases and global options)
 
 
 Test list of internal help commands
 
   $ hg help debug
   debug commands (internal and unsupported):
   
    debugancestor
                  find the ancestor revision of two revisions in a given index
    debugapplystreamclonebundle
                  apply a stream clone bundle file
    debugbuilddag
                  builds a repo with a given DAG from scratch in the current
                  empty repo
    debugbundle   lists the contents of a bundle
    debugcheckstate
                  validate the correctness of the current dirstate
    debugcommands
                  list all available commands and options
    debugcomplete
                  returns the completion list associated with the given command
    debugcreatestreamclonebundle
                  create a stream clone bundle file
    debugdag      format the changelog or an index DAG as a concise textual
                  description
    debugdata     dump the contents of a data file revision
    debugdate     parse and display a date
    debugdeltachain
                  dump information about delta chains in a revlog
    debugdirstate
                  show the contents of the current dirstate
    debugdiscovery
                  runs the changeset discovery protocol in isolation
    debugextensions
                  show information about active extensions
    debugfileset  parse and apply a fileset specification
    debugfsinfo   show information detected about current filesystem
    debuggetbundle
                  retrieves a bundle from a repo
    debugignore   display the combined ignore pattern and information about
                  ignored files
    debugindex    dump the contents of an index file
    debugindexdot
                  dump an index DAG as a graphviz dot file
    debuginstall  test Mercurial installation
    debugknown    test whether node ids are known to a repo
    debuglocks    show or modify state of locks
    debugmergestate
                  print merge state
    debugnamecomplete
                  complete "names" - tags, open branch names, bookmark names
    debugobsolete
                  create arbitrary obsolete marker
    debugoptDEP   (no help text available)
    debugoptEXP   (no help text available)
    debugpathcomplete
                  complete part or all of a tracked path
    debugpushkey  access the pushkey key/value protocol
    debugpvec     (no help text available)
    debugrebuilddirstate
                  rebuild the dirstate as it would look like for the given
                  revision
    debugrebuildfncache
                  rebuild the fncache file
    debugrename   dump rename information
    debugrevlog   show data and statistics about a revlog
    debugrevspec  parse and apply a revision specification
    debugsetparents
                  manually set the parents of the current working directory
    debugsub      (no help text available)
    debugsuccessorssets
                  show set of successors for revision
    debugwalk     show how files match on given patterns
    debugwireargs
                  (no help text available)
   
   (use "hg help -v debug" to show built-in aliases and global options)
 
 internals topic renders index of available sub-topics
 
   $ hg help internals
   Technical implementation topics
   """""""""""""""""""""""""""""""
   
        bundles       container for exchange of repository data
        changegroups  representation of revlog data
+       requirements  repository requirements
        revlogs       revision storage mechanism
 
 sub-topics can be accessed
 
   $ hg help internals.changegroups
       Changegroups
       ============
   
       Changegroups are representations of repository revlog data, specifically
       the changelog, manifest, and filelogs.
   
       There are 3 versions of changegroups: "1", "2", and "3". From a high-
       level, versions "1" and "2" are almost exactly the same, with the only
       difference being a header on entries in the changeset segment. Version "3"
       adds support for exchanging treemanifests and includes revlog flags in the
       delta header.
   
       Changegroups consists of 3 logical segments:
   
         +---------------------------------+
         |           |          |          |
         | changeset | manifest | filelogs |
         |           |          |          |
         +---------------------------------+
   
       The principle building block of each segment is a *chunk*. A *chunk* is a
       framed piece of data:
   
         +---------------------------------------+
         |           |                           |
         |  length   |           data            |
         | (32 bits) |       <length> bytes      |
         |           |                           |
         +---------------------------------------+
   
       Each chunk starts with a 32-bit big-endian signed integer indicating the
       length of the raw data that follows.
   
       There is a special case chunk that has 0 length ("0x00000000"). We call
       this an *empty chunk*.
   
       Delta Groups
       ------------
   
       A *delta group* expresses the content of a revlog as a series of deltas,
       or patches against previous revisions.
   
       Delta groups consist of 0 or more *chunks* followed by the *empty chunk*
       to signal the end of the delta group:
   
         +------------------------------------------------------------------------+
         |                |             |               |             |           |
         | chunk0 length  | chunk0 data | chunk1 length | chunk1 data |    0x0    |
         |   (32 bits)    |  (various)  |   (32 bits)   |  (various)  | (32 bits) |
         |                |             |               |             |           |
         +------------------------------------------------------------+-----------+
   
       Each *chunk*'s data consists of the following:
   
         +-----------------------------------------+
         |              |              |           |
         | delta header | mdiff header |   delta   |
         |  (various)   |  (12 bytes)  | (various) |
         |              |              |           |
         +-----------------------------------------+
   
       The *length* field is the byte length of the remaining 3 logical pieces of
       data. The *delta* is a diff from an existing entry in the changelog.
   
       The *delta header* is different between versions "1", "2", and "3" of the
       changegroup format.
   
       Version 1:
   
         +------------------------------------------------------+
         |            |             |             |             |
         |    node    |   p1 node   |   p2 node   |  link node  |
         | (20 bytes) |  (20 bytes) |  (20 bytes) |  (20 bytes) |
         |            |             |             |             |
         +------------------------------------------------------+
   
       Version 2:
   
         +------------------------------------------------------------------+
         |            |             |             |            |            |
         |    node    |   p1 node   |   p2 node   | base node  | link node  |
         | (20 bytes) |  (20 bytes) |  (20 bytes) | (20 bytes) | (20 bytes) |
         |            |             |             |            |            |
         +------------------------------------------------------------------+
   
       Version 3:
   
         +------------------------------------------------------------------------------+
         |            |             |             |            |            |           |
         |    node    |   p1 node   |   p2 node   | base node  | link node  | flags     |
         | (20 bytes) |  (20 bytes) |  (20 bytes) | (20 bytes) | (20 bytes) | (2 bytes) |
         |            |             |             |            |            |           |
         +------------------------------------------------------------------------------+
   
       The *mdiff header* consists of 3 32-bit big-endian signed integers
       describing offsets at which to apply the following delta content:
   
         +-------------------------------------+
         |           |            |            |
         |  offset   | old length | new length |
         | (32 bits) |  (32 bits) |  (32 bits) |
         |           |            |            |
         +-------------------------------------+
   
       In version 1, the delta is always applied against the previous node from
       the changegroup or the first parent if this is the first entry in the
       changegroup.
   
       In version 2, the delta base node is encoded in the entry in the
       changegroup. This allows the delta to be expressed against any parent,
       which can result in smaller deltas and more efficient encoding of data.
   
       Changeset Segment
       -----------------
   
       The *changeset segment* consists of a single *delta group* holding
       changelog data. It is followed by an *empty chunk* to denote the boundary
       to the *manifests segment*.
   
       Manifest Segment
       ----------------
   
       The *manifest segment* consists of a single *delta group* holding manifest
       data. It is followed by an *empty chunk* to denote the boundary to the
       *filelogs segment*.
   
       Filelogs Segment
       ----------------
   
       The *filelogs* segment consists of multiple sub-segments, each
       corresponding to an individual file whose data is being described:
   
         +--------------------------------------+
         |          |          |          |     |
         | filelog0 | filelog1 | filelog2 | ... |
         |          |          |          |     |
         +--------------------------------------+
   
       In version "3" of the changegroup format, filelogs may include directory
       logs when treemanifests are in use. directory logs are identified by
       having a trailing '/' on their filename (see below).
   
       The final filelog sub-segment is followed by an *empty chunk* to denote
       the end of the segment and the overall changegroup.
   
       Each filelog sub-segment consists of the following:
   
         +------------------------------------------+
         |               |            |             |
         | filename size |  filename  | delta group |
         |   (32 bits)   |  (various) |  (various)  |
         |               |            |             |
         +------------------------------------------+
   
       That is, a *chunk* consisting of the filename (not terminated or padded)
       followed by N chunks constituting the *delta group* for this file.
 
 Test list of commands with command with no help text
 
   $ hg help helpext
   helpext extension - no help text available
   
   list of commands:
   
    nohelp        (no help text available)
   
   (use "hg help -v helpext" to show built-in aliases and global options)
 
 
 test deprecated and experimental options are hidden in command help
   $ hg help debugoptDEP
   hg debugoptDEP
   
   (no help text available)
   
   options:
   
   (some details hidden, use --verbose to show complete help)
 
   $ hg help debugoptEXP
   hg debugoptEXP
   
   (no help text available)
   
   options:
   
   (some details hidden, use --verbose to show complete help)
 
 test deprecated and experimental options is shown with -v
   $ hg help -v debugoptDEP | grep dopt
     --dopt option is (DEPRECATED)
   $ hg help -v debugoptEXP | grep eopt
     --eopt option is (EXPERIMENTAL)
 
 #if gettext
 test deprecated option is hidden with translation with untranslated description
 (use many globy for not failing on changed transaction)
   $ LANGUAGE=sv hg help debugoptDEP
   hg debugoptDEP
   
   (*) (glob)
   
   options:
   
   (some details hidden, use --verbose to show complete help)
 #endif
 
 Test commands that collide with topics (issue4240)
 
   $ hg config -hq
   hg config [-u] [NAME]...
   
   show combined config settings from all hgrc files
   $ hg showconfig -hq
   hg config [-u] [NAME]...
   
   show combined config settings from all hgrc files
 
 Test a help topic
 
   $ hg help revs
   Specifying Single Revisions
   """""""""""""""""""""""""""
   
       Mercurial supports several ways to specify individual revisions.
   
       A plain integer is treated as a revision number. Negative integers are
       treated as sequential offsets from the tip, with -1 denoting the tip, -2
       denoting the revision prior to the tip, and so forth.
   
       A 40-digit hexadecimal string is treated as a unique revision identifier.
   
       A hexadecimal string less than 40 characters long is treated as a unique
       revision identifier and is referred to as a short-form identifier. A
       short-form identifier is only valid if it is the prefix of exactly one
       full-length identifier.
   
       Any other string is treated as a bookmark, tag, or branch name. A bookmark
       is a movable pointer to a revision. A tag is a permanent name associated
       with a revision. A branch name denotes the tipmost open branch head of
       that branch - or if they are all closed, the tipmost closed head of the
       branch. Bookmark, tag, and branch names must not contain the ":"
       character.
   
       The reserved name "tip" always identifies the most recent revision.
   
       The reserved name "null" indicates the null revision. This is the revision
       of an empty repository, and the parent of revision 0.
   
       The reserved name "." indicates the working directory parent. If no
       working directory is checked out, it is equivalent to null. If an
       uncommitted merge is in progress, "." is the revision of the first parent.
 
 Test repeated config section name
 
   $ hg help config.host
       "http_proxy.host"
           Host name and (optional) port of the proxy server, for example
           "myproxy:8000".
   
       "smtp.host"
           Host name of mail server, e.g. "mail.example.com".
   
 Unrelated trailing paragraphs shouldn't be included
 
   $ hg help config.extramsg | grep '^$'
   
 
 Test capitalized section name
 
   $ hg help scripting.HGPLAIN > /dev/null
 
 Help subsection:
 
   $ hg help config.charsets |grep "Email example:" > /dev/null
   [1]
 
 Show nested definitions
 ("profiling.type"[break]"ls"[break]"stat"[break])
 
   $ hg help config.type | egrep '^$'|wc -l
   \s*3 (re)
 
 Separate sections from subsections
 
   $ hg help config.format | egrep '^    ("|-)|^\s*$' | uniq
       "format"
       --------
   
       "usegeneraldelta"
   
       "dotencode"
   
       "usefncache"
   
       "usestore"
   
       "profiling"
       -----------
   
       "format"
   
       "progress"
       ----------
   
       "format"
   
 
 Last item in help config.*:
 
   $ hg help config.`hg help config|grep '^    "'| \
   >       tail -1|sed 's![ "]*!!g'`| \
   >   grep "hg help -c config" > /dev/null
   [1]
 
 note to use help -c for general hg help config:
 
   $ hg help config |grep "hg help -c config" > /dev/null
 
 Test templating help
 
   $ hg help templating | egrep '(desc|diffstat|firstline|nonempty)  '
       desc          String. The text of the changeset description.
       diffstat      String. Statistics of changes with the following format:
       firstline     Any text. Returns the first line of text.
       nonempty      Any text. Returns '(none)' if the string is empty.
 
 Test deprecated items
 
   $ hg help -v templating | grep currentbookmark
       currentbookmark
   $ hg help templating | (grep currentbookmark || true)
 
 Test help hooks
 
   $ cat > helphook1.py <<EOF
   > from mercurial import help
   > 
   > def rewrite(ui, topic, doc):
   >     return doc + '\nhelphook1\n'
   > 
   > def extsetup(ui):
   >     help.addtopichook('revsets', rewrite)
   > EOF
   $ cat > helphook2.py <<EOF
   > from mercurial import help
   > 
   > def rewrite(ui, topic, doc):
   >     return doc + '\nhelphook2\n'
   > 
   > def extsetup(ui):
   >     help.addtopichook('revsets', rewrite)
   > EOF
   $ echo '[extensions]' >> $HGRCPATH
   $ echo "helphook1 = `pwd`/helphook1.py" >> $HGRCPATH
   $ echo "helphook2 = `pwd`/helphook2.py" >> $HGRCPATH
   $ hg help revsets | grep helphook
       helphook1
       helphook2
 
 help -c should only show debug --debug
 
   $ hg help -c --debug|egrep debug|wc -l|egrep '^\s*0\s*$'
   [1]
 
 help -c should only show deprecated for -v
 
   $ hg help -c -v|egrep DEPRECATED|wc -l|egrep '^\s*0\s*$'
   [1]
 
 Test -s / --system
 
   $ hg help config.files -s windows |grep 'etc/mercurial' | \
   > wc -l | sed -e 's/ //g'
   0
   $ hg help config.files --system unix | grep 'USER' | \
   > wc -l | sed -e 's/ //g'
   0
 
 Test -e / -c / -k combinations
 
   $ hg help -c|egrep '^[A-Z].*:|^ debug'
   Commands:
   $ hg help -e|egrep '^[A-Z].*:|^ debug'
   Extensions:
   $ hg help -k|egrep '^[A-Z].*:|^ debug'
   Topics:
   Commands:
   Extensions:
   Extension Commands:
   $ hg help -c schemes
   abort: no such help topic: schemes
   (try "hg help --keyword schemes")
   [255]
   $ hg help -e schemes |head -1
   schemes extension - extend schemes with shortcuts to repository swarms
   $ hg help -c -k dates |egrep '^(Topics|Extensions|Commands):'
   Commands:
   $ hg help -e -k a |egrep '^(Topics|Extensions|Commands):'
   Extensions:
   $ hg help -e -c -k date |egrep '^(Topics|Extensions|Commands):'
   Extensions:
   Commands:
   $ hg help -c commit > /dev/null
   $ hg help -e -c commit > /dev/null
   $ hg help -e commit > /dev/null
   abort: no such help topic: commit
   (try "hg help --keyword commit")
   [255]
 
 Test keyword search help
 
   $ cat > prefixedname.py <<EOF
   > '''matched against word "clone"
   > '''
   > EOF
   $ echo '[extensions]' >> $HGRCPATH
   $ echo "dot.dot.prefixedname = `pwd`/prefixedname.py" >> $HGRCPATH
   $ hg help -k clone
   Topics:
   
    config     Configuration Files
    extensions Using Additional Features
    glossary   Glossary
    phases     Working with Phases
    subrepos   Subrepositories
    urls       URL Paths
   
   Commands:
   
    bookmarks create a new bookmark or list existing bookmarks
    clone     make a copy of an existing repository
    paths     show aliases for remote repositories
    update    update working directory (or switch revisions)
   
   Extensions:
   
    clonebundles advertise pre-generated bundles to seed clones
    prefixedname matched against word "clone"
    relink       recreates hardlinks between repository clones
   
   Extension Commands:
   
    qclone clone main and patch repository at same time
 
 Test unfound topic
 
   $ hg help nonexistingtopicthatwillneverexisteverever
   abort: no such help topic: nonexistingtopicthatwillneverexisteverever
   (try "hg help --keyword nonexistingtopicthatwillneverexisteverever")
   [255]
 
 Test unfound keyword
 
   $ hg help --keyword nonexistingwordthatwillneverexisteverever
   abort: no matches
   (try "hg help" for a list of topics)
   [255]
 
 Test omit indicating for help
 
   $ cat > addverboseitems.py <<EOF
   > '''extension to test omit indicating.
   > 
   > This paragraph is never omitted (for extension)
   > 
   > .. container:: verbose
   > 
   >   This paragraph is omitted,
   >   if :hg:\`help\` is invoked without \`\`-v\`\` (for extension)
   > 
   > This paragraph is never omitted, too (for extension)
   > '''
   > 
   > from mercurial import help, commands
   > testtopic = """This paragraph is never omitted (for topic).
   > 
   > .. container:: verbose
   > 
   >   This paragraph is omitted,
   >   if :hg:\`help\` is invoked without \`\`-v\`\` (for topic)
   > 
   > This paragraph is never omitted, too (for topic)
   > """
   > def extsetup(ui):
   >     help.helptable.append((["topic-containing-verbose"],
   >                            "This is the topic to test omit indicating.",
   >                            lambda ui: testtopic))
   > EOF
   $ echo '[extensions]' >> $HGRCPATH
   $ echo "addverboseitems = `pwd`/addverboseitems.py" >> $HGRCPATH
   $ hg help addverboseitems
   addverboseitems extension - extension to test omit indicating.
   
   This paragraph is never omitted (for extension)
   
   This paragraph is never omitted, too (for extension)
   
   (some details hidden, use --verbose to show complete help)
   
   no commands defined
   $ hg help -v addverboseitems
   addverboseitems extension - extension to test omit indicating.
   
   This paragraph is never omitted (for extension)
   
   This paragraph is omitted, if 'hg help' is invoked without "-v" (for
   extension)
   
   This paragraph is never omitted, too (for extension)
   
   no commands defined
   $ hg help topic-containing-verbose
   This is the topic to test omit indicating.
   """"""""""""""""""""""""""""""""""""""""""
   
       This paragraph is never omitted (for topic).
   
       This paragraph is never omitted, too (for topic)
   
   (some details hidden, use --verbose to show complete help)
   $ hg help -v topic-containing-verbose
   This is the topic to test omit indicating.
   """"""""""""""""""""""""""""""""""""""""""
   
       This paragraph is never omitted (for topic).
   
       This paragraph is omitted, if 'hg help' is invoked without "-v" (for
       topic)
   
       This paragraph is never omitted, too (for topic)
 
 Test section lookup
 
   $ hg help revset.merge
       "merge()"
         Changeset is a merge changeset.
   
   $ hg help glossary.dag
       DAG
           The repository of changesets of a distributed version control system
           (DVCS) can be described as a directed acyclic graph (DAG), consisting
           of nodes and edges, where nodes correspond to changesets and edges
           imply a parent -> child relation. This graph can be visualized by
           graphical tools such as 'hg log --graph'. In Mercurial, the DAG is
           limited by the requirement for children to have at most two parents.
   
 
   $ hg help hgrc.paths
       "paths"
       -------
   
       Assigns symbolic names and behavior to repositories.
   
       Options are symbolic names defining the URL or directory that is the
       location of the repository. Example:
   
         [paths]
         my_server = https://example.com/my_repo
         local_path = /home/me/repo
   
       These symbolic names can be used from the command line. To pull from
       "my_server": 'hg pull my_server'. To push to "local_path": 'hg push
       local_path'.
   
       Options containing colons (":") denote sub-options that can influence
       behavior for that specific path. Example:
   
         [paths]
         my_server = https://example.com/my_path
         my_server:pushurl = ssh://example.com/my_path
   
       The following sub-options can be defined:
   
       "pushurl"
          The URL to use for push operations. If not defined, the location
          defined by the path's main entry is used.
   
       The following special named paths exist:
   
       "default"
          The URL or directory to use when no source or remote is specified.
   
          'hg clone' will automatically define this path to the location the
          repository was cloned from.
   
       "default-push"
          (deprecated) The URL or directory for the default 'hg push' location.
          "default:pushurl" should be used instead.
   
   $ hg help glossary.mcguffin
   abort: help section not found
   [255]
 
   $ hg help glossary.mc.guffin
   abort: help section not found
   [255]
 
   $ hg help template.files
       files         List of strings. All files modified, added, or removed by
                     this changeset.
 
 Test dynamic list of merge tools only shows up once
   $ hg help merge-tools
   Merge Tools
   """""""""""
   
       To merge files Mercurial uses merge tools.
   
       A merge tool combines two different versions of a file into a merged file.
       Merge tools are given the two files and the greatest common ancestor of
       the two file versions, so they can determine the changes made on both
       branches.
   
       Merge tools are used both for 'hg resolve', 'hg merge', 'hg update', 'hg
       backout' and in several extensions.
   
       Usually, the merge tool tries to automatically reconcile the files by
       combining all non-overlapping changes that occurred separately in the two
       different evolutions of the same initial base file. Furthermore, some
       interactive merge programs make it easier to manually resolve conflicting
       merges, either in a graphical way, or by inserting some conflict markers.
       Mercurial does not include any interactive merge programs but relies on
       external tools for that.
   
       Available merge tools
       =====================
   
       External merge tools and their properties are configured in the merge-
       tools configuration section - see hgrc(5) - but they can often just be
       named by their executable.
   
       A merge tool is generally usable if its executable can be found on the
       system and if it can handle the merge. The executable is found if it is an
       absolute or relative executable path or the name of an application in the
       executable search path. The tool is assumed to be able to handle the merge
       if it can handle symlinks if the file is a symlink, if it can handle
       binary files if the file is binary, and if a GUI is available if the tool
       requires a GUI.
   
       There are some internal merge tools which can be used. The internal merge
       tools are:
   
       ":dump"
         Creates three versions of the files to merge, containing the contents of
         local, other and base. These files can then be used to perform a merge
         manually. If the file to be merged is named "a.txt", these files will
         accordingly be named "a.txt.local", "a.txt.other" and "a.txt.base" and
         they will be placed in the same directory as "a.txt".
   
       ":fail"
         Rather than attempting to merge files that were modified on both
         branches, it marks them as unresolved. The resolve command must be used
         to resolve these conflicts.
   
       ":local"
         Uses the local version of files as the merged version.
   
       ":merge"
         Uses the internal non-interactive simple merge algorithm for merging
         files. It will fail if there are any conflicts and leave markers in the
         partially merged file. Markers will have two sections, one for each side
         of merge.
   
       ":merge-local"
         Like :merge, but resolve all conflicts non-interactively in favor of the
         local changes.
   
       ":merge-other"
         Like :merge, but resolve all conflicts non-interactively in favor of the
         other changes.
   
       ":merge3"
         Uses the internal non-interactive simple merge algorithm for merging
         files. It will fail if there are any conflicts and leave markers in the
         partially merged file. Marker will have three sections, one from each
         side of the merge and one for the base content.
   
       ":other"
         Uses the other version of files as the merged version.
   
       ":prompt"
         Asks the user which of the local or the other version to keep as the
         merged version.
   
       ":tagmerge"
         Uses the internal tag merge algorithm (experimental).
   
       ":union"
         Uses the internal non-interactive simple merge algorithm for merging
         files. It will use both left and right sides for conflict regions. No
         markers are inserted.
   
       Internal tools are always available and do not require a GUI but will by
       default not handle symlinks or binary files.
   
       Choosing a merge tool
       =====================
   
       Mercurial uses these rules when deciding which merge tool to use:
   
       1. If a tool has been specified with the --tool option to merge or
          resolve, it is used.  If it is the name of a tool in the merge-tools
          configuration, its configuration is used. Otherwise the specified tool
          must be executable by the shell.
       2. If the "HGMERGE" environment variable is present, its value is used and
          must be executable by the shell.
       3. If the filename of the file to be merged matches any of the patterns in
          the merge-patterns configuration section, the first usable merge tool
          corresponding to a matching pattern is used. Here, binary capabilities
          of the merge tool are not considered.
       4. If ui.merge is set it will be considered next. If the value is not the
          name of a configured tool, the specified value is used and must be
          executable by the shell. Otherwise the named tool is used if it is
          usable.
       5. If any usable merge tools are present in the merge-tools configuration
          section, the one with the highest priority is used.
       6. If a program named "hgmerge" can be found on the system, it is used -
          but it will by default not be used for symlinks and binary files.
       7. If the file to be merged is not binary and is not a symlink, then
          internal ":merge" is used.
       8. The merge of the file fails and must be resolved before commit.
   
       Note:
          After selecting a merge program, Mercurial will by default attempt to
          merge the files using a simple merge algorithm first. Only if it
          doesn't succeed because of conflicting changes Mercurial will actually
          execute the merge program. Whether to use the simple merge algorithm
          first can be controlled by the premerge setting of the merge tool.
          Premerge is enabled by default unless the file is binary or a symlink.
   
       See the merge-tools and ui sections of hgrc(5) for details on the
       configuration of merge tools.
 
 Test usage of section marks in help documents
 
   $ cd "$TESTDIR"/../doc
   $ python check-seclevel.py
   $ cd $TESTTMP
 
 #if serve
 
 Test the help pages in hgweb.
 
 Dish up an empty repo; serve it cold.
 
   $ hg init "$TESTTMP/test"
   $ hg serve -R "$TESTTMP/test" -n test -p $HGPORT -d --pid-file=hg.pid
   $ cat hg.pid >> $DAEMON_PIDS
 
   $ get-with-headers.py 127.0.0.1:$HGPORT "help"
   200 Script output follows
   
   <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
   <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en-US">
   <head>
   <link rel="icon" href="/static/hgicon.png" type="image/png" />
   <meta name="robots" content="index, nofollow" />
   <link rel="stylesheet" href="/static/style-paper.css" type="text/css" />
   <script type="text/javascript" src="/static/mercurial.js"></script>
   
   <title>Help: Index</title>
   </head>
   <body>
   
   <div class="container">
   <div class="menu">
   <div class="logo">
   <a href="https://mercurial-scm.org/">
   <img src="/static/hglogo.png" alt="mercurial" /></a>
   </div>
   <ul>
   <li><a href="/shortlog">log</a></li>
   <li><a href="/graph">graph</a></li>
   <li><a href="/tags">tags</a></li>
   <li><a href="/bookmarks">bookmarks</a></li>
   <li><a href="/branches">branches</a></li>
   </ul>
   <ul>
   <li class="active">help</li>
   </ul>
   </div>
   
   <div class="main">
   <h2 class="breadcrumb"><a href="/">Mercurial</a> </h2>
   <form class="search" action="/log">
   
   <p><input name="rev" id="search1" type="text" size="30" /></p>
   <div id="hint">Find changesets by keywords (author, files, the commit message), revision
   number or hash, or <a href="/help/revsets">revset expression</a>.</div>
   </form>
   <table class="bigtable">
   <tr><td colspan="2"><h2><a name="main" href="#topics">Topics</a></h2></td></tr>
   
   <tr><td>
   <a href="/help/config">
   config
   </a>
   </td><td>
   Configuration Files
   </td></tr>
   <tr><td>
   <a href="/help/dates">
   dates
   </a>
   </td><td>
   Date Formats
   </td></tr>
   <tr><td>
   <a href="/help/diffs">
   diffs
   </a>
   </td><td>
   Diff Formats
   </td></tr>
   <tr><td>
   <a href="/help/environment">
   environment
   </a>
   </td><td>
   Environment Variables
   </td></tr>
   <tr><td>
   <a href="/help/extensions">
   extensions
   </a>
   </td><td>
   Using Additional Features
   </td></tr>
   <tr><td>
   <a href="/help/filesets">
   filesets
   </a>
   </td><td>
   Specifying File Sets
   </td></tr>
   <tr><td>
   <a href="/help/glossary">
   glossary
   </a>
   </td><td>
   Glossary
   </td></tr>
   <tr><td>
   <a href="/help/hgignore">
   hgignore
   </a>
   </td><td>
   Syntax for Mercurial Ignore Files
   </td></tr>
   <tr><td>
   <a href="/help/hgweb">
   hgweb
   </a>
   </td><td>
   Configuring hgweb
   </td></tr>
   <tr><td>
   <a href="/help/internals">
   internals
   </a>
   </td><td>
   Technical implementation topics
   </td></tr>
   <tr><td>
   <a href="/help/merge-tools">
   merge-tools
   </a>
   </td><td>
   Merge Tools
   </td></tr>
   <tr><td>
   <a href="/help/multirevs">
   multirevs
   </a>
   </td><td>
   Specifying Multiple Revisions
   </td></tr>
   <tr><td>
   <a href="/help/patterns">
   patterns
   </a>
   </td><td>
   File Name Patterns
   </td></tr>
   <tr><td>
   <a href="/help/phases">
   phases
   </a>
   </td><td>
   Working with Phases
   </td></tr>
   <tr><td>
   <a href="/help/revisions">
   revisions
   </a>
   </td><td>
   Specifying Single Revisions
   </td></tr>
   <tr><td>
   <a href="/help/revsets">
   revsets
   </a>
   </td><td>
   Specifying Revision Sets
   </td></tr>
   <tr><td>
   <a href="/help/scripting">
   scripting
   </a>
   </td><td>
   Using Mercurial from scripts and automation
   </td></tr>
   <tr><td>
   <a href="/help/subrepos">
   subrepos
   </a>
   </td><td>
   Subrepositories
   </td></tr>
   <tr><td>
   <a href="/help/templating">
   templating
   </a>
   </td><td>
   Template Usage
   </td></tr>
   <tr><td>
   <a href="/help/urls">
   urls
   </a>
   </td><td>
   URL Paths
   </td></tr>
   <tr><td>
   <a href="/help/topic-containing-verbose">
   topic-containing-verbose
   </a>
   </td><td>
   This is the topic to test omit indicating.
   </td></tr>
   
   
   <tr><td colspan="2"><h2><a name="main" href="#main">Main Commands</a></h2></td></tr>
   
   <tr><td>
   <a href="/help/add">
   add
   </a>
   </td><td>
   add the specified files on the next commit
   </td></tr>
   <tr><td>
   <a href="/help/annotate">
   annotate
   </a>
   </td><td>
   show changeset information by line for each file
   </td></tr>
   <tr><td>
   <a href="/help/clone">
   clone
   </a>
   </td><td>
   make a copy of an existing repository
   </td></tr>
   <tr><td>
   <a href="/help/commit">
   commit
   </a>
   </td><td>
   commit the specified files or all outstanding changes
   </td></tr>
   <tr><td>
   <a href="/help/diff">
   diff
   </a>
   </td><td>
   diff repository (or selected files)
   </td></tr>
   <tr><td>
   <a href="/help/export">
   export
   </a>
   </td><td>
   dump the header and diffs for one or more changesets
   </td></tr>
   <tr><td>
   <a href="/help/forget">
   forget
   </a>
   </td><td>
   forget the specified files on the next commit
   </td></tr>
   <tr><td>
   <a href="/help/init">
   init
   </a>
   </td><td>
   create a new repository in the given directory
   </td></tr>
   <tr><td>
   <a href="/help/log">
   log
   </a>
   </td><td>
   show revision history of entire repository or files
   </td></tr>
   <tr><td>
   <a href="/help/merge">
   merge
   </a>
   </td><td>
   merge another revision into working directory
   </td></tr>
   <tr><td>
   <a href="/help/pull">
   pull
   </a>
   </td><td>
   pull changes from the specified source
   </td></tr>
   <tr><td>
   <a href="/help/push">
   push
   </a>
   </td><td>
   push changes to the specified destination
   </td></tr>
   <tr><td>
   <a href="/help/remove">
   remove
   </a>
   </td><td>
   remove the specified files on the next commit
   </td></tr>
   <tr><td>
   <a href="/help/serve">
   serve
   </a>
   </td><td>
   start stand-alone webserver
   </td></tr>
   <tr><td>
   <a href="/help/status">
   status
   </a>
   </td><td>
   show changed files in the working directory
   </td></tr>
   <tr><td>
   <a href="/help/summary">
   summary
   </a>
   </td><td>
   summarize working directory state
   </td></tr>
   <tr><td>
   <a href="/help/update">
   update
   </a>
   </td><td>
   update working directory (or switch revisions)
   </td></tr>
   
   
   
   <tr><td colspan="2"><h2><a name="other" href="#other">Other Commands</a></h2></td></tr>
   
   <tr><td>
   <a href="/help/addremove">
   addremove
   </a>
   </td><td>
   add all new files, delete all missing files
   </td></tr>
   <tr><td>
   <a href="/help/archive">
   archive
   </a>
   </td><td>
   create an unversioned archive of a repository revision
   </td></tr>
   <tr><td>
   <a href="/help/backout">
   backout
   </a>
   </td><td>
   reverse effect of earlier changeset
   </td></tr>
   <tr><td>
   <a href="/help/bisect">
   bisect
   </a>
   </td><td>
   subdivision search of changesets
   </td></tr>
   <tr><td>
   <a href="/help/bookmarks">
   bookmarks
   </a>
   </td><td>
   create a new bookmark or list existing bookmarks
   </td></tr>
   <tr><td>
   <a href="/help/branch">
   branch
   </a>
   </td><td>
   set or show the current branch name
   </td></tr>
   <tr><td>
   <a href="/help/branches">
   branches
   </a>
   </td><td>
   list repository named branches
   </td></tr>
   <tr><td>
   <a href="/help/bundle">
   bundle
   </a>
   </td><td>
   create a changegroup file
   </td></tr>
   <tr><td>
   <a href="/help/cat">
   cat
   </a>
   </td><td>
   output the current or given revision of files
   </td></tr>
   <tr><td>
   <a href="/help/config">
   config
   </a>
   </td><td>
   show combined config settings from all hgrc files
   </td></tr>
   <tr><td>
   <a href="/help/copy">
   copy
   </a>
   </td><td>
   mark files as copied for the next commit
   </td></tr>
   <tr><td>
   <a href="/help/files">
   files
   </a>
   </td><td>
   list tracked files
   </td></tr>
   <tr><td>
   <a href="/help/graft">
   graft
   </a>
   </td><td>
   copy changes from other branches onto the current branch
   </td></tr>
   <tr><td>
   <a href="/help/grep">
   grep
   </a>
   </td><td>
   search for a pattern in specified files and revisions
   </td></tr>
   <tr><td>
   <a href="/help/heads">
   heads
   </a>
   </td><td>
   show branch heads
   </td></tr>
   <tr><td>
   <a href="/help/help">
   help
   </a>
   </td><td>
   show help for a given topic or a help overview
   </td></tr>
   <tr><td>
   <a href="/help/identify">
   identify
   </a>
   </td><td>
   identify the working directory or specified revision
   </td></tr>
   <tr><td>
   <a href="/help/import">
   import
   </a>
   </td><td>
   import an ordered set of patches
   </td></tr>
   <tr><td>
   <a href="/help/incoming">
   incoming
   </a>
   </td><td>
   show new changesets found in source
   </td></tr>
   <tr><td>
   <a href="/help/manifest">
   manifest
   </a>
   </td><td>
   output the current or given revision of the project manifest
   </td></tr>
   <tr><td>
   <a href="/help/nohelp">
   nohelp
   </a>
   </td><td>
   (no help text available)
   </td></tr>
   <tr><td>
   <a href="/help/outgoing">
   outgoing
   </a>
   </td><td>
   show changesets not found in the destination
   </td></tr>
   <tr><td>
   <a href="/help/paths">
   paths
   </a>
   </td><td>
   show aliases for remote repositories
   </td></tr>
   <tr><td>
   <a href="/help/phase">
   phase
   </a>
   </td><td>
   set or show the current phase name
   </td></tr>
   <tr><td>
   <a href="/help/recover">
   recover
   </a>
   </td><td>
   roll back an interrupted transaction
   </td></tr>
   <tr><td>
   <a href="/help/rename">
   rename
   </a>
   </td><td>
   rename files; equivalent of copy + remove
   </td></tr>
   <tr><td>
   <a href="/help/resolve">
   resolve
   </a>
   </td><td>
   redo merges or set/view the merge status of files
   </td></tr>
   <tr><td>
   <a href="/help/revert">
   revert
   </a>
   </td><td>
   restore files to their checkout state
   </td></tr>
   <tr><td>
   <a href="/help/root">
   root
   </a>
   </td><td>
   print the root (top) of the current working directory
   </td></tr>
   <tr><td>
   <a href="/help/tag">
   tag
   </a>
   </td><td>
   add one or more tags for the current or given revision
   </td></tr>
   <tr><td>
   <a href="/help/tags">
   tags
   </a>
   </td><td>
   list repository tags
   </td></tr>
   <tr><td>
   <a href="/help/unbundle">
   unbundle
   </a>
   </td><td>
   apply one or more changegroup files
   </td></tr>
   <tr><td>
   <a href="/help/verify">
   verify
   </a>
   </td><td>
   verify the integrity of the repository
   </td></tr>
   <tr><td>
   <a href="/help/version">
   version
   </a>
   </td><td>
   output version and copyright information
   </td></tr>
   
   
   </table>
   </div>
   </div>
   
   <script type="text/javascript">process_dates()</script>
   
   
   </body>
   </html>
   
 
   $ get-with-headers.py 127.0.0.1:$HGPORT "help/add"
   200 Script output follows
   
   <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
   <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en-US">
   <head>
   <link rel="icon" href="/static/hgicon.png" type="image/png" />
   <meta name="robots" content="index, nofollow" />
   <link rel="stylesheet" href="/static/style-paper.css" type="text/css" />
   <script type="text/javascript" src="/static/mercurial.js"></script>
   
   <title>Help: add</title>
   </head>
   <body>
   
   <div class="container">
   <div class="menu">
   <div class="logo">
   <a href="https://mercurial-scm.org/">
   <img src="/static/hglogo.png" alt="mercurial" /></a>
   </div>
   <ul>
   <li><a href="/shortlog">log</a></li>
   <li><a href="/graph">graph</a></li>
   <li><a href="/tags">tags</a></li>
   <li><a href="/bookmarks">bookmarks</a></li>
   <li><a href="/branches">branches</a></li>
   </ul>
   <ul>
    <li class="active"><a href="/help">help</a></li>
   </ul>
   </div>
   
   <div class="main">
   <h2 class="breadcrumb"><a href="/">Mercurial</a> </h2>
   <h3>Help: add</h3>
   
   <form class="search" action="/log">
   
   <p><input name="rev" id="search1" type="text" size="30" /></p>
   <div id="hint">Find changesets by keywords (author, files, the commit message), revision
   number or hash, or <a href="/help/revsets">revset expression</a>.</div>
   </form>
   <div id="doc">
   <p>
   hg add [OPTION]... [FILE]...
   </p>
   <p>
   add the specified files on the next commit
   </p>
   <p>
   Schedule files to be version controlled and added to the
   repository.
   </p>
   <p>
   The files will be added to the repository at the next commit. To
   undo an add before that, see 'hg forget'.
   </p>
   <p>
   If no names are given, add all files to the repository (except
   files matching &quot;.hgignore&quot;).
   </p>
   <p>
   Examples:
   </p>
   <ul>
    <li> New (unknown) files are added   automatically by 'hg add':
   <pre>
   \$ ls (re)
   foo.c
   \$ hg status (re)
   ? foo.c
   \$ hg add (re)
   adding foo.c
   \$ hg status (re)
   A foo.c
   </pre>
    <li> Specific files to be added can be specified:
   <pre>
   \$ ls (re)
   bar.c  foo.c
   \$ hg status (re)
   ? bar.c
   ? foo.c
   \$ hg add bar.c (re)
   \$ hg status (re)
   A bar.c
   ? foo.c
   </pre>
   </ul>
   <p>
   Returns 0 if all files are successfully added.
   </p>
   <p>
   options ([+] can be repeated):
   </p>
   <table>
   <tr><td>-I</td>
   <td>--include PATTERN [+]</td>
   <td>include names matching the given patterns</td></tr>
   <tr><td>-X</td>
   <td>--exclude PATTERN [+]</td>
   <td>exclude names matching the given patterns</td></tr>
   <tr><td>-S</td>
   <td>--subrepos</td>
   <td>recurse into subrepositories</td></tr>
   <tr><td>-n</td>
   <td>--dry-run</td>
   <td>do not perform actions, just print output</td></tr>
   </table>
   <p>
   global options ([+] can be repeated):
   </p>
   <table>
   <tr><td>-R</td>
   <td>--repository REPO</td>
   <td>repository root directory or name of overlay bundle file</td></tr>
   <tr><td></td>
   <td>--cwd DIR</td>
   <td>change working directory</td></tr>
   <tr><td>-y</td>
   <td>--noninteractive</td>
   <td>do not prompt, automatically pick the first choice for all prompts</td></tr>
   <tr><td>-q</td>
   <td>--quiet</td>
   <td>suppress output</td></tr>
   <tr><td>-v</td>
   <td>--verbose</td>
   <td>enable additional output</td></tr>
   <tr><td></td>
   <td>--config CONFIG [+]</td>
   <td>set/override config option (use 'section.name=value')</td></tr>
   <tr><td></td>
   <td>--debug</td>
   <td>enable debugging output</td></tr>
   <tr><td></td>
   <td>--debugger</td>
   <td>start debugger</td></tr>
   <tr><td></td>
   <td>--encoding ENCODE</td>
   <td>set the charset encoding (default: ascii)</td></tr>
   <tr><td></td>
   <td>--encodingmode MODE</td>
   <td>set the charset encoding mode (default: strict)</td></tr>
   <tr><td></td>
   <td>--traceback</td>
   <td>always print a traceback on exception</td></tr>
   <tr><td></td>
   <td>--time</td>
   <td>time how long the command takes</td></tr>
   <tr><td></td>
   <td>--profile</td>
   <td>print command execution profile</td></tr>
   <tr><td></td>
   <td>--version</td>
   <td>output version information and exit</td></tr>
   <tr><td>-h</td>
   <td>--help</td>
   <td>display help and exit</td></tr>
   <tr><td></td>
   <td>--hidden</td>
   <td>consider hidden changesets</td></tr>
   </table>
   
   </div>
   </div>
   </div>
   
   <script type="text/javascript">process_dates()</script>
   
   
   </body>
   </html>
   
 
   $ get-with-headers.py 127.0.0.1:$HGPORT "help/remove"
   200 Script output follows
   
   <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
   <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en-US">
   <head>
   <link rel="icon" href="/static/hgicon.png" type="image/png" />
   <meta name="robots" content="index, nofollow" />
   <link rel="stylesheet" href="/static/style-paper.css" type="text/css" />
   <script type="text/javascript" src="/static/mercurial.js"></script>
   
   <title>Help: remove</title>
   </head>
   <body>
   
   <div class="container">
   <div class="menu">
   <div class="logo">
   <a href="https://mercurial-scm.org/">
   <img src="/static/hglogo.png" alt="mercurial" /></a>
   </div>
   <ul>
   <li><a href="/shortlog">log</a></li>
   <li><a href="/graph">graph</a></li>
   <li><a href="/tags">tags</a></li>
   <li><a href="/bookmarks">bookmarks</a></li>
   <li><a href="/branches">branches</a></li>
   </ul>
   <ul>
    <li class="active"><a href="/help">help</a></li>
   </ul>
   </div>
   
   <div class="main">
   <h2 class="breadcrumb"><a href="/">Mercurial</a> </h2>
   <h3>Help: remove</h3>
   
   <form class="search" action="/log">
   
   <p><input name="rev" id="search1" type="text" size="30" /></p>
   <div id="hint">Find changesets by keywords (author, files, the commit message), revision
   number or hash, or <a href="/help/revsets">revset expression</a>.</div>
   </form>
   <div id="doc">
   <p>
   hg remove [OPTION]... FILE...
   </p>
   <p>
   aliases: rm
   </p>
   <p>
   remove the specified files on the next commit
   </p>
   <p>
   Schedule the indicated files for removal from the current branch.
   </p>
   <p>
   This command schedules the files to be removed at the next commit.
   To undo a remove before that, see 'hg revert'. To undo added
   files, see 'hg forget'.
   </p>
   <p>
   -A/--after can be used to remove only files that have already
   been deleted, -f/--force can be used to force deletion, and -Af
   can be used to remove files from the next revision without
   deleting them from the working directory.
   </p>
   <p>
   The following table details the behavior of remove for different
   file states (columns) and option combinations (rows). The file
   states are Added [A], Clean [C], Modified [M] and Missing [!]
   (as reported by 'hg status'). The actions are Warn, Remove
   (from branch) and Delete (from disk):
   </p>
   <table>
   <tr><td>opt/state</td>
   <td>A</td>
   <td>C</td>
   <td>M</td>
   <td>!</td></tr>
   <tr><td>none</td>
   <td>W</td>
   <td>RD</td>
   <td>W</td>
   <td>R</td></tr>
   <tr><td>-f</td>
   <td>R</td>
   <td>RD</td>
   <td>RD</td>
   <td>R</td></tr>
   <tr><td>-A</td>
   <td>W</td>
   <td>W</td>
   <td>W</td>
   <td>R</td></tr>
   <tr><td>-Af</td>
   <td>R</td>
   <td>R</td>
   <td>R</td>
   <td>R</td></tr>
   </table>
   <p>
   <b>Note:</b> 
   </p>
   <p>
   'hg remove' never deletes files in Added [A] state from the
   working directory, not even if &quot;--force&quot; is specified.
   </p>
   <p>
   Returns 0 on success, 1 if any warnings encountered.
   </p>
   <p>
   options ([+] can be repeated):
   </p>
   <table>
   <tr><td>-A</td>
   <td>--after</td>
   <td>record delete for missing files</td></tr>
   <tr><td>-f</td>
   <td>--force</td>
   <td>remove (and delete) file even if added or modified</td></tr>
   <tr><td>-S</td>
   <td>--subrepos</td>
   <td>recurse into subrepositories</td></tr>
   <tr><td>-I</td>
   <td>--include PATTERN [+]</td>
   <td>include names matching the given patterns</td></tr>
   <tr><td>-X</td>
   <td>--exclude PATTERN [+]</td>
   <td>exclude names matching the given patterns</td></tr>
   </table>
   <p>
   global options ([+] can be repeated):
   </p>
   <table>
   <tr><td>-R</td>
   <td>--repository REPO</td>
   <td>repository root directory or name of overlay bundle file</td></tr>
   <tr><td></td>
   <td>--cwd DIR</td>
   <td>change working directory</td></tr>
   <tr><td>-y</td>
   <td>--noninteractive</td>
   <td>do not prompt, automatically pick the first choice for all prompts</td></tr>
   <tr><td>-q</td>
   <td>--quiet</td>
   <td>suppress output</td></tr>
   <tr><td>-v</td>
   <td>--verbose</td>
   <td>enable additional output</td></tr>
   <tr><td></td>
   <td>--config CONFIG [+]</td>
   <td>set/override config option (use 'section.name=value')</td></tr>
   <tr><td></td>
   <td>--debug</td>
   <td>enable debugging output</td></tr>
   <tr><td></td>
   <td>--debugger</td>
   <td>start debugger</td></tr>
   <tr><td></td>
   <td>--encoding ENCODE</td>
   <td>set the charset encoding (default: ascii)</td></tr>
   <tr><td></td>
   <td>--encodingmode MODE</td>
   <td>set the charset encoding mode (default: strict)</td></tr>
   <tr><td></td>
   <td>--traceback</td>
   <td>always print a traceback on exception</td></tr>
   <tr><td></td>
   <td>--time</td>
   <td>time how long the command takes</td></tr>
   <tr><td></td>
   <td>--profile</td>
   <td>print command execution profile</td></tr>
   <tr><td></td>
   <td>--version</td>
   <td>output version information and exit</td></tr>
   <tr><td>-h</td>
   <td>--help</td>
   <td>display help and exit</td></tr>
   <tr><td></td>
   <td>--hidden</td>
   <td>consider hidden changesets</td></tr>
   </table>
   
   </div>
   </div>
   </div>
   
   <script type="text/javascript">process_dates()</script>
   
   
   </body>
   </html>
   
 
   $ get-with-headers.py 127.0.0.1:$HGPORT "help/revisions"
   200 Script output follows
   
   <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
   <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en-US">
   <head>
   <link rel="icon" href="/static/hgicon.png" type="image/png" />
   <meta name="robots" content="index, nofollow" />
   <link rel="stylesheet" href="/static/style-paper.css" type="text/css" />
   <script type="text/javascript" src="/static/mercurial.js"></script>
   
   <title>Help: revisions</title>
   </head>
   <body>
   
   <div class="container">
   <div class="menu">
   <div class="logo">
   <a href="https://mercurial-scm.org/">
   <img src="/static/hglogo.png" alt="mercurial" /></a>
   </div>
   <ul>
   <li><a href="/shortlog">log</a></li>
   <li><a href="/graph">graph</a></li>
   <li><a href="/tags">tags</a></li>
   <li><a href="/bookmarks">bookmarks</a></li>
   <li><a href="/branches">branches</a></li>
   </ul>
   <ul>
    <li class="active"><a href="/help">help</a></li>
   </ul>
   </div>
   
   <div class="main">
   <h2 class="breadcrumb"><a href="/">Mercurial</a> </h2>
   <h3>Help: revisions</h3>
   
   <form class="search" action="/log">
   
   <p><input name="rev" id="search1" type="text" size="30" /></p>
   <div id="hint">Find changesets by keywords (author, files, the commit message), revision
   number or hash, or <a href="/help/revsets">revset expression</a>.</div>
   </form>
   <div id="doc">
   <h1>Specifying Single Revisions</h1>
   <p>
   Mercurial supports several ways to specify individual revisions.
   </p>
   <p>
   A plain integer is treated as a revision number. Negative integers are
   treated as sequential offsets from the tip, with -1 denoting the tip,
   -2 denoting the revision prior to the tip, and so forth.
   </p>
   <p>
   A 40-digit hexadecimal string is treated as a unique revision
   identifier.
   </p>
   <p>
   A hexadecimal string less than 40 characters long is treated as a
   unique revision identifier and is referred to as a short-form
   identifier. A short-form identifier is only valid if it is the prefix
   of exactly one full-length identifier.
   </p>
   <p>
   Any other string is treated as a bookmark, tag, or branch name. A
   bookmark is a movable pointer to a revision. A tag is a permanent name
   associated with a revision. A branch name denotes the tipmost open branch head
   of that branch - or if they are all closed, the tipmost closed head of the
   branch. Bookmark, tag, and branch names must not contain the &quot;:&quot; character.
   </p>
   <p>
   The reserved name &quot;tip&quot; always identifies the most recent revision.
   </p>
   <p>
   The reserved name &quot;null&quot; indicates the null revision. This is the
   revision of an empty repository, and the parent of revision 0.
   </p>
   <p>
   The reserved name &quot;.&quot; indicates the working directory parent. If no
   working directory is checked out, it is equivalent to null. If an
   uncommitted merge is in progress, &quot;.&quot; is the revision of the first
   parent.
   </p>
   
   </div>
   </div>
   </div>
   
   <script type="text/javascript">process_dates()</script>
   
   
   </body>
   </html>
   
 
 Sub-topic indexes rendered properly
 
   $ get-with-headers.py 127.0.0.1:$HGPORT "help/internals"
   200 Script output follows
   
   <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
   <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en-US">
   <head>
   <link rel="icon" href="/static/hgicon.png" type="image/png" />
   <meta name="robots" content="index, nofollow" />
   <link rel="stylesheet" href="/static/style-paper.css" type="text/css" />
   <script type="text/javascript" src="/static/mercurial.js"></script>
   
   <title>Help: internals</title>
   </head>
   <body>
   
   <div class="container">
   <div class="menu">
   <div class="logo">
   <a href="https://mercurial-scm.org/">
   <img src="/static/hglogo.png" alt="mercurial" /></a>
   </div>
   <ul>
   <li><a href="/shortlog">log</a></li>
   <li><a href="/graph">graph</a></li>
   <li><a href="/tags">tags</a></li>
   <li><a href="/bookmarks">bookmarks</a></li>
   <li><a href="/branches">branches</a></li>
   </ul>
   <ul>
   <li><a href="/help">help</a></li>
   </ul>
   </div>
   
   <div class="main">
   <h2 class="breadcrumb"><a href="/">Mercurial</a> </h2>
   <form class="search" action="/log">
   
   <p><input name="rev" id="search1" type="text" size="30" /></p>
   <div id="hint">Find changesets by keywords (author, files, the commit message), revision
   number or hash, or <a href="/help/revsets">revset expression</a>.</div>
   </form>
   <table class="bigtable">
   <tr><td colspan="2"><h2><a name="main" href="#topics">Topics</a></h2></td></tr>
   
   <tr><td>
   <a href="/help/internals.bundles">
   bundles
   </a>
   </td><td>
   container for exchange of repository data
   </td></tr>
   <tr><td>
   <a href="/help/internals.changegroups">
   changegroups
   </a>
   </td><td>
   representation of revlog data
   </td></tr>
   <tr><td>
+  <a href="/help/internals.requirements">
+  requirements
+  </a>
+  </td><td>
+  repository requirements
+  </td></tr>
+  <tr><td>
   <a href="/help/internals.revlogs">
   revlogs
   </a>
   </td><td>
   revision storage mechanism
   </td></tr>
   
   
   
   
   
   </table>
   </div>
   </div>
   
   <script type="text/javascript">process_dates()</script>
   
   
   </body>
   </html>
   
 
 Sub-topic topics rendered properly
 
   $ get-with-headers.py 127.0.0.1:$HGPORT "help/internals.changegroups"
   200 Script output follows
   
   <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
   <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en-US">
   <head>
   <link rel="icon" href="/static/hgicon.png" type="image/png" />
   <meta name="robots" content="index, nofollow" />
   <link rel="stylesheet" href="/static/style-paper.css" type="text/css" />
   <script type="text/javascript" src="/static/mercurial.js"></script>
   
   <title>Help: internals.changegroups</title>
   </head>
   <body>
   
   <div class="container">
   <div class="menu">
   <div class="logo">
   <a href="https://mercurial-scm.org/">
   <img src="/static/hglogo.png" alt="mercurial" /></a>
   </div>
   <ul>
   <li><a href="/shortlog">log</a></li>
   <li><a href="/graph">graph</a></li>
   <li><a href="/tags">tags</a></li>
   <li><a href="/bookmarks">bookmarks</a></li>
   <li><a href="/branches">branches</a></li>
   </ul>
   <ul>
    <li class="active"><a href="/help">help</a></li>
   </ul>
   </div>
   
   <div class="main">
   <h2 class="breadcrumb"><a href="/">Mercurial</a> </h2>
   <h3>Help: internals.changegroups</h3>
   
   <form class="search" action="/log">
   
   <p><input name="rev" id="search1" type="text" size="30" /></p>
   <div id="hint">Find changesets by keywords (author, files, the commit message), revision
   number or hash, or <a href="/help/revsets">revset expression</a>.</div>
   </form>
   <div id="doc">
   <h1>representation of revlog data</h1>
   <h2>Changegroups</h2>
   <p>
   Changegroups are representations of repository revlog data, specifically
   the changelog, manifest, and filelogs.
   </p>
   <p>
   There are 3 versions of changegroups: &quot;1&quot;, &quot;2&quot;, and &quot;3&quot;. From a
   high-level, versions &quot;1&quot; and &quot;2&quot; are almost exactly the same, with
   the only difference being a header on entries in the changeset
   segment. Version &quot;3&quot; adds support for exchanging treemanifests and
   includes revlog flags in the delta header.
   </p>
   <p>
   Changegroups consists of 3 logical segments:
   </p>
   <pre>
   +---------------------------------+
   |           |          |          |
   | changeset | manifest | filelogs |
   |           |          |          |
   +---------------------------------+
   </pre>
   <p>
   The principle building block of each segment is a *chunk*. A *chunk*
   is a framed piece of data:
   </p>
   <pre>
   +---------------------------------------+
   |           |                           |
   |  length   |           data            |
   | (32 bits) |       &lt;length&gt; bytes      |
   |           |                           |
   +---------------------------------------+
   </pre>
   <p>
   Each chunk starts with a 32-bit big-endian signed integer indicating
   the length of the raw data that follows.
   </p>
   <p>
   There is a special case chunk that has 0 length (&quot;0x00000000&quot;). We
   call this an *empty chunk*.
   </p>
   <h3>Delta Groups</h3>
   <p>
   A *delta group* expresses the content of a revlog as a series of deltas,
   or patches against previous revisions.
   </p>
   <p>
   Delta groups consist of 0 or more *chunks* followed by the *empty chunk*
   to signal the end of the delta group:
   </p>
   <pre>
   +------------------------------------------------------------------------+
   |                |             |               |             |           |
   | chunk0 length  | chunk0 data | chunk1 length | chunk1 data |    0x0    |
   |   (32 bits)    |  (various)  |   (32 bits)   |  (various)  | (32 bits) |
   |                |             |               |             |           |
   +------------------------------------------------------------+-----------+
   </pre>
   <p>
   Each *chunk*'s data consists of the following:
   </p>
   <pre>
   +-----------------------------------------+
   |              |              |           |
   | delta header | mdiff header |   delta   |
   |  (various)   |  (12 bytes)  | (various) |
   |              |              |           |
   +-----------------------------------------+
   </pre>
   <p>
   The *length* field is the byte length of the remaining 3 logical pieces
   of data. The *delta* is a diff from an existing entry in the changelog.
   </p>
   <p>
   The *delta header* is different between versions &quot;1&quot;, &quot;2&quot;, and
   &quot;3&quot; of the changegroup format.
   </p>
   <p>
   Version 1:
   </p>
   <pre>
   +------------------------------------------------------+
   |            |             |             |             |
   |    node    |   p1 node   |   p2 node   |  link node  |
   | (20 bytes) |  (20 bytes) |  (20 bytes) |  (20 bytes) |
   |            |             |             |             |
   +------------------------------------------------------+
   </pre>
   <p>
   Version 2:
   </p>
   <pre>
   +------------------------------------------------------------------+
   |            |             |             |            |            |
   |    node    |   p1 node   |   p2 node   | base node  | link node  |
   | (20 bytes) |  (20 bytes) |  (20 bytes) | (20 bytes) | (20 bytes) |
   |            |             |             |            |            |
   +------------------------------------------------------------------+
   </pre>
   <p>
   Version 3:
   </p>
   <pre>
   +------------------------------------------------------------------------------+
   |            |             |             |            |            |           |
   |    node    |   p1 node   |   p2 node   | base node  | link node  | flags     |
   | (20 bytes) |  (20 bytes) |  (20 bytes) | (20 bytes) | (20 bytes) | (2 bytes) |
   |            |             |             |            |            |           |
   +------------------------------------------------------------------------------+
   </pre>
   <p>
   The *mdiff header* consists of 3 32-bit big-endian signed integers
   describing offsets at which to apply the following delta content:
   </p>
   <pre>
   +-------------------------------------+
   |           |            |            |
   |  offset   | old length | new length |
   | (32 bits) |  (32 bits) |  (32 bits) |
   |           |            |            |
   +-------------------------------------+
   </pre>
   <p>
   In version 1, the delta is always applied against the previous node from
   the changegroup or the first parent if this is the first entry in the
   changegroup.
   </p>
   <p>
   In version 2, the delta base node is encoded in the entry in the
   changegroup. This allows the delta to be expressed against any parent,
   which can result in smaller deltas and more efficient encoding of data.
   </p>
   <h3>Changeset Segment</h3>
   <p>
   The *changeset segment* consists of a single *delta group* holding
   changelog data. It is followed by an *empty chunk* to denote the
   boundary to the *manifests segment*.
   </p>
   <h3>Manifest Segment</h3>
   <p>
   The *manifest segment* consists of a single *delta group* holding
   manifest data. It is followed by an *empty chunk* to denote the boundary
   to the *filelogs segment*.
   </p>
   <h3>Filelogs Segment</h3>
   <p>
   The *filelogs* segment consists of multiple sub-segments, each
   corresponding to an individual file whose data is being described:
   </p>
   <pre>
   +--------------------------------------+
   |          |          |          |     |
   | filelog0 | filelog1 | filelog2 | ... |
   |          |          |          |     |
   +--------------------------------------+
   </pre>
   <p>
   In version &quot;3&quot; of the changegroup format, filelogs may include
   directory logs when treemanifests are in use. directory logs are
   identified by having a trailing '/' on their filename (see below).
   </p>
   <p>
   The final filelog sub-segment is followed by an *empty chunk* to denote
   the end of the segment and the overall changegroup.
   </p>
   <p>
   Each filelog sub-segment consists of the following:
   </p>
   <pre>
   +------------------------------------------+
   |               |            |             |
   | filename size |  filename  | delta group |
   |   (32 bits)   |  (various) |  (various)  |
   |               |            |             |
   +------------------------------------------+
   </pre>
   <p>
   That is, a *chunk* consisting of the filename (not terminated or padded)
   followed by N chunks constituting the *delta group* for this file.
   </p>
   
   </div>
   </div>
   </div>
   
   <script type="text/javascript">process_dates()</script>
   
   
   </body>
   </html>
   
 
   $ killdaemons.py
 
 #endif