help: add 'mergetools' alias for the 'merge-tools' help topic

The '-' in 'merge-tools' is surprising but necessary in the configuration.
Let's help those who forget that and are looking for help.

mercurial/help.py

@@ -1,203 +1,203 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 i18n import gettext, _
 import itertools, sys, os
 import extensions, revset, fileset, templatekw, templatefilters, filemerge
 import encoding, util, minirst
 
 def listexts(header, exts, indent=1):
     '''return a text listing of the given extensions'''
     rst = []
     if exts:
         rst.append('\n%s\n\n' % header)
         for name, desc in sorted(exts.iteritems()):
             rst.append('%s:%s: %s\n' % (' ' * indent, name, desc))
     return rst
 
 def extshelp():
     rst = loaddoc('extensions')().splitlines(True)
     rst.extend(listexts(_('enabled extensions:'), extensions.enabled()))
     rst.extend(listexts(_('disabled extensions:'), extensions.disabled()))
     doc = ''.join(rst)
     return doc
 
 def optrst(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 _("DEPRECATED") in desc and not verbose:
             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))
 
     rst = minirst.maketable(data, 1)
 
     if multioccur:
         rst.append(_("\n[+] marked option can be specified multiple times\n"))
 
     return ''.join(rst)
 
 def topicmatch(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:
         if (sum(map(lowercontains, names))
             or lowercontains(header)
             or lowercontains(doc())):
             results['topics'].append((names[0], header))
     import commands # avoid cycle
     for cmd, entry in commands.table.iteritems():
         if cmd.startswith('debug'):
             continue
         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.split('|')[0].lstrip('^')
             results['commands'].append((cmdname, summary))
     for name, docs in itertools.chain(
         extensions.enabled().iteritems(),
         extensions.disabled().iteritems()):
         # extensions.load ignores the UI argument
         mod = extensions.load(None, name, '')
         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.split('|')[0].lstrip('^')
                 if entry[0].__doc__:
                     cmddoc = gettext(entry[0].__doc__).splitlines()[0]
                 else:
                     cmddoc = _('(no help text available)')
                 results['extensioncommands'].append((cmdname, cmddoc))
     return results
 
 def loaddoc(topic):
     """Return a delayed loader for help/topic.txt."""
 
     def loader():
         if util.mainfrozen():
             module = sys.executable
         else:
             module = __file__
         base = os.path.dirname(module)
 
         for dir in ('.', '..'):
             docdir = os.path.join(base, dir, 'help')
             if os.path.isdir(docdir):
                 break
 
         path = os.path.join(docdir, topic + ".txt")
         doc = gettext(util.readfile(path))
         for rewriter in helphooks.get(topic, []):
             doc = rewriter(topic, doc)
         return doc
 
     return loader
 
 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'], _('Merge Tools'), loaddoc('merge-tools')),
+    (['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')),
 ])
 
 # 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(topic, doc, marker, items):
     """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:
             continue
         text = gettext(text)
         lines = text.splitlines()
         doclines = [(lines[0])]
         for l in lines[1:]:
             # Stop once we find some Python doctest
             if l.strip().startswith('>>>'):
                 break
             doclines.append('  ' + l.strip())
         entries.append('\n'.join(doclines))
     entries = '\n\n'.join(entries)
     return doc.replace(marker, entries)
 
 def addtopicsymbols(topic, marker, symbols):
     def add(topic, doc):
         return makeitemsdoc(topic, doc, marker, symbols)
     addtopichook(topic, add)
 
 addtopicsymbols('filesets', '.. predicatesmarker', fileset.symbols)
 addtopicsymbols('merge-tools', '.. internaltoolsmarker', filemerge.internals)
 addtopicsymbols('revsets', '.. predicatesmarker', revset.symbols)
 addtopicsymbols('templates', '.. keywordsmarker', templatekw.dockeywords)
 addtopicsymbols('templates', '.. filtersmarker', templatefilters.filters)