view mercurial/help.py @ 12296:d7fff529d85d

clone: only use stream when we understand the revlog format

This patch fixes issues with stream cloning in the presense of parentdelta,
lwcopy and similar additions that change the interpretation of the revlog
format, or the format itself.

Currently, the stream capability is sent like this:
stream=<version of changelog>

But the client doesn't actually check the version number; also, it only checks
the changelog and it doesn't capture the interpretation-changes and
flag-changes in parentdelta and lwcopy.

This patch removes the 'stream' capability whenever we use a non-basic revlog
format, to prevent old clients from receiving incorrect data. In those cases,
a new capability called 'streamreqs' is added instead. Instead of a revlog
version, it comes with a list of revlog-format relevant requirements, which
are a subset of the repository requirements, excluding things that are not
relevant for stream.

New clients use this to determine whether or not they can stream. Old clients
only look for the 'stream' capability, as always. New servers will still send
this when serving old repositories.

# 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


def moduledoc(file):
    '''return the top-level python documentation for the given file

    Loosely inspired by pydoc.source_synopsis(), but rewritten to
    handle triple quotes and to return the whole text instead of just
    the synopsis'''
    result = []

    line = file.readline()
    while line[:1] == '#' or not line.strip():
        line = file.readline()
        if not line:
            break

    start = line[:3]
    if start == '"""' or start == "'''":
        line = line[3:]
        while line:
            if line.rstrip().endswith(start):
                line = line.split(start)[0]
                if line:
                    result.append(line)
                break
            elif not line:
                return None # unmatched delimiter
            result.append(line)
            line = file.readline()
    else:
        return None

    return ''.join(result)

def listexts(header, exts, maxlength, indent=1):
    '''return a text listing of the given extensions'''
    if not exts:
        return ''
    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')()

    exts, maxlength = extensions.enabled()
    doc += listexts(_('enabled extensions:'), exts, maxlength)

    exts, maxlength = extensions.disabled()
    doc += listexts(_('disabled extensions:'), exts, maxlength)

    return doc

def loaddoc(topic):
    """Return a delayed loader for help/topic.txt."""

    def loader():
        if hasattr(sys, 'frozen'):
            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")
        return gettext(open(path).read())
    return loader

helptable = [
    (["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')),
    (['revsets'], _("Specifying Revision Sets"), loaddoc('revsets')),
    (['diffs'], _('Diff Formats'), loaddoc('diffs')),
    (['templating', 'templates'], _('Template Usage'),
     loaddoc('templates')),
    (['urls'], _('URL Paths'), loaddoc('urls')),
    (["extensions"], _("Using additional features"), extshelp),
    (["hgweb"], _("Configuring hgweb"), loaddoc('hgweb')),
    (["glossary"], _("Glossary"), loaddoc('glossary')),
]