view hgext/win32text.py @ 46843:728d89f6f9b1

refactor: prefer checks against nullrev over nullid

A common pattern is using a changeset context and obtaining the node to
compare against nullid. Change this to obtain the nullrev instead. In
the future, the nullid becomes a property of the repository and is no
longer a global constant, so using nullrev is much easier to reason
about. Python function call overhead makes the difference moot, but
future changes will result in more dictionary lookups otherwise, so
prefer the simpler pattern.

Differential Revision: https://phab.mercurial-scm.org/D10290

# win32text.py - LF <-> CRLF/CR translation utilities for Windows/Mac users
#
#  Copyright 2005, 2007-2009 Olivia Mackall <[e-mail]> and others
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

'''perform automatic newline conversion (DEPRECATED)

  Deprecation: The win32text extension requires each user to configure
  the extension again and again for each clone since the configuration
  is not copied when cloning.

  We have therefore made the ``eol`` as an alternative. The ``eol``
  uses a version controlled file for its configuration and each clone
  will therefore use the right settings from the start.

To perform automatic newline conversion, use::

  [extensions]
  win32text =
  [encode]
  ** = cleverencode:
  # or ** = macencode:

  [decode]
  ** = cleverdecode:
  # or ** = macdecode:

If not doing conversion, to make sure you do not commit CRLF/CR by accident::

  [hooks]
  pretxncommit.crlf = python:hgext.win32text.forbidcrlf
  # or pretxncommit.cr = python:hgext.win32text.forbidcr

To do the same check on a server to prevent CRLF/CR from being
pushed or pulled::

  [hooks]
  pretxnchangegroup.crlf = python:hgext.win32text.forbidcrlf
  # or pretxnchangegroup.cr = python:hgext.win32text.forbidcr
'''

from __future__ import absolute_import

import re
from mercurial.i18n import _
from mercurial.node import short
from mercurial import (
    pycompat,
    registrar,
)
from mercurial.utils import stringutil

# Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for
# extensions which SHIP WITH MERCURIAL. Non-mainline extensions should
# be specifying the version(s) of Mercurial they are tested with, or
# leave the attribute unspecified.
testedwith = b'ships-with-hg-core'

configtable = {}
configitem = registrar.configitem(configtable)

configitem(
    b'win32text',
    b'warn',
    default=True,
)

# regexp for single LF without CR preceding.
re_single_lf = re.compile(b'(^|[^\r])\n', re.MULTILINE)

newlinestr = {b'\r\n': b'CRLF', b'\r': b'CR'}
filterstr = {b'\r\n': b'clever', b'\r': b'mac'}


def checknewline(s, newline, ui=None, repo=None, filename=None):
    # warn if already has 'newline' in repository.
    # it might cause unexpected eol conversion.
    # see issue 302:
    #   https://bz.mercurial-scm.org/302
    if newline in s and ui and filename and repo:
        ui.warn(
            _(
                b'WARNING: %s already has %s line endings\n'
                b'and does not need EOL conversion by the win32text plugin.\n'
                b'Before your next commit, please reconsider your '
                b'encode/decode settings in \nMercurial.ini or %s.\n'
            )
            % (filename, newlinestr[newline], repo.vfs.join(b'hgrc'))
        )


def dumbdecode(s, cmd, **kwargs):
    checknewline(s, b'\r\n', **kwargs)
    # replace single LF to CRLF
    return re_single_lf.sub(b'\\1\r\n', s)


def dumbencode(s, cmd):
    return s.replace(b'\r\n', b'\n')


def macdumbdecode(s, cmd, **kwargs):
    checknewline(s, b'\r', **kwargs)
    return s.replace(b'\n', b'\r')


def macdumbencode(s, cmd):
    return s.replace(b'\r', b'\n')


def cleverdecode(s, cmd, **kwargs):
    if not stringutil.binary(s):
        return dumbdecode(s, cmd, **kwargs)
    return s


def cleverencode(s, cmd):
    if not stringutil.binary(s):
        return dumbencode(s, cmd)
    return s


def macdecode(s, cmd, **kwargs):
    if not stringutil.binary(s):
        return macdumbdecode(s, cmd, **kwargs)
    return s


def macencode(s, cmd):
    if not stringutil.binary(s):
        return macdumbencode(s, cmd)
    return s


_filters = {
    b'dumbdecode:': dumbdecode,
    b'dumbencode:': dumbencode,
    b'cleverdecode:': cleverdecode,
    b'cleverencode:': cleverencode,
    b'macdumbdecode:': macdumbdecode,
    b'macdumbencode:': macdumbencode,
    b'macdecode:': macdecode,
    b'macencode:': macencode,
}


def forbidnewline(ui, repo, hooktype, node, newline, **kwargs):
    halt = False
    seen = set()
    # we try to walk changesets in reverse order from newest to
    # oldest, so that if we see a file multiple times, we take the
    # newest version as canonical. this prevents us from blocking a
    # changegroup that contains an unacceptable commit followed later
    # by a commit that fixes the problem.
    tip = repo[b'tip']
    for rev in pycompat.xrange(
        repo.changelog.tiprev(), repo[node].rev() - 1, -1
    ):
        c = repo[rev]
        for f in c.files():
            if f in seen or f not in tip or f not in c:
                continue
            seen.add(f)
            data = c[f].data()
            if not stringutil.binary(data) and newline in data:
                if not halt:
                    ui.warn(
                        _(
                            b'attempt to commit or push text file(s) '
                            b'using %s line endings\n'
                        )
                        % newlinestr[newline]
                    )
                ui.warn(_(b'in %s: %s\n') % (short(c.node()), f))
                halt = True
    if halt and hooktype == b'pretxnchangegroup':
        crlf = newlinestr[newline].lower()
        filter = filterstr[newline]
        ui.warn(
            _(
                b'\nTo prevent this mistake in your local repository,\n'
                b'add to Mercurial.ini or .hg/hgrc:\n'
                b'\n'
                b'[hooks]\n'
                b'pretxncommit.%s = python:hgext.win32text.forbid%s\n'
                b'\n'
                b'and also consider adding:\n'
                b'\n'
                b'[extensions]\n'
                b'win32text =\n'
                b'[encode]\n'
                b'** = %sencode:\n'
                b'[decode]\n'
                b'** = %sdecode:\n'
            )
            % (crlf, crlf, filter, filter)
        )
    return halt


def forbidcrlf(ui, repo, hooktype, node, **kwargs):
    return forbidnewline(ui, repo, hooktype, node, b'\r\n', **kwargs)


def forbidcr(ui, repo, hooktype, node, **kwargs):
    return forbidnewline(ui, repo, hooktype, node, b'\r', **kwargs)


def reposetup(ui, repo):
    if not repo.local():
        return
    for name, fn in pycompat.iteritems(_filters):
        repo.adddatafilter(name, fn)


def extsetup(ui):
    # deprecated config: win32text.warn
    if ui.configbool(b'win32text', b'warn'):
        ui.warn(
            _(
                b"win32text is deprecated: "
                b"https://mercurial-scm.org/wiki/Win32TextExtension\n"
            )
        )