mercurial/help.py

patch: fix fuzzing of hunks without previous lines (issue3264)

When applying hunks such as:

  @@ -2,1 +2,2 @@
   context
  +change

fuzzing would empty the "old" block and make patchfile.apply() traceback.
Instead, we apply the new block at specified location without testing.

The "bottom hunk" test was removed as patch(1) has no problem applying hunk
with no context in the middle of a file.

# 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 sys, os
import extensions, revset, fileset, templatekw, templatefilters
import util

def listexts(header, exts, indent=1):
    '''return a text listing of the given extensions'''
    if not exts:
        return ''
    maxlength = max(len(e) for e in exts)
    result = '\n%s\n\n' % header
    for name, desc in sorted(exts.iteritems()):
        result += '%s%-*s %s\n' % (' ' * indent, maxlength + 2,
                                   ':%s:' % name, desc)
    return result

def extshelp():
    doc = loaddoc('extensions')()
    doc += listexts(_('enabled extensions:'), extensions.enabled())
    doc += listexts(_('disabled extensions:'), extensions.disabled())
    return doc

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')),
    (['revs', 'revisions'], _('Specifying Single Revisions'),
     loaddoc('revisions')),
    (['mrevs', 'multirevs'], _('Specifying Multiple Revisions'),
     loaddoc('multirevs')),
    (['revset', 'revsets'], _("Specifying Revision Sets"), loaddoc('revsets')),
    (['fileset', 'filesets'], _("Specifying File Sets"), loaddoc('filesets')),
    (['diffs'], _('Diff Formats'), loaddoc('diffs')),
    (['merge-tools'], _('Merge Tools'), loaddoc('merge-tools')),
    (['templating', 'templates'], _('Template Usage'),
     loaddoc('templates')),
    (['urls'], _('URL Paths'), loaddoc('urls')),
    (["extensions"], _("Using additional features"), extshelp),
   (["subrepo", "subrepos"], _("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()
        lines[1:] = [('  ' + l.strip()) for l in lines[1:]]
        entries.append('\n'.join(lines))
    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('revsets', '.. predicatesmarker', revset.symbols)
addtopicsymbols('templates', '.. keywordsmarker', templatekw.keywords)
addtopicsymbols('templates', '.. filtersmarker', templatefilters.filters)