~bzr-pqm/bzr/bzr.dev

# Copyright (C) 2005, 2006 Canonical Ltd

#

# This program is free software; you can redistribute it and/or modify

# it under the terms of the GNU General Public License as published by

# the Free Software Foundation; either version 2 of the License, or

# (at your option) any later version.

#

# This program is distributed in the hope that it will be useful,

# but WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

# GNU General Public License for more details.

#

# You should have received a copy of the GNU General Public License

# along with this program; if not, write to the Free Software

# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

from __future__ import absolute_import

import errno

import os

from subprocess import Popen, PIPE

from bzrlib.errors import NoDiff3

from bzrlib.textfile import check_text_path

"""Diff and patch functionality"""

__docformat__ = "restructuredtext"

_do_close_fds = True

if os.name == 'nt':

    _do_close_fds = False

def write_to_cmd(args, input=""):

    """Spawn a process, and wait for the result

    If the process is killed, an exception is raised

    :param args: The command line, the first entry should be the program name

    :param input: [optional] The text to send the process on stdin

    :return: (stdout, stderr, status)

    """

    process = Popen(args, bufsize=len(input), stdin=PIPE, stdout=PIPE,

                    stderr=PIPE, close_fds=_do_close_fds)

    stdout, stderr = process.communicate(input)

    status = process.wait()

    if status < 0:

        raise Exception("%s killed by signal %i" (args[0], -status))

    return stdout, stderr, status

def patch(patch_contents, filename, output_filename=None, reverse=False):

    """Apply a patch to a file, to produce another output file.  This is should

    be suitable for our limited purposes.

    :param patch_contents: The contents of the patch to apply

    :type patch_contents: str

    :param filename: the name of the file to apply the patch to

    :type filename: str

    :param output_filename: The filename to produce.  If None, file is \

    modified in-place

    :type output_filename: str or NoneType

    :param reverse: If true, apply the patch in reverse

    :type reverse: bool

    :return: 0 on success, 1 if some hunks failed

    """

    args = ["patch", "-f", "-s", "--posix", "--binary"]

    if reverse:

        args.append("--reverse")

    if output_filename is not None:

        args.extend(("-o", output_filename))

    args.append(filename)

    stdout, stderr, status = write_to_cmd(args, patch_contents)

    return status

def diff3(out_file, mine_path, older_path, yours_path):

    def add_label(args, label):

        args.extend(("-L", label))

    check_text_path(mine_path)

    check_text_path(older_path)

    check_text_path(yours_path)

    args = ['diff3', "-E", "--merge"]

    add_label(args, "TREE")

    add_label(args, "ANCESTOR")

    add_label(args, "MERGE-SOURCE")

    args.extend((mine_path, older_path, yours_path))

    try:

        output, stderr, status = write_to_cmd(args)

    except OSError, e:

        if e.errno == errno.ENOENT:

            raise NoDiff3

        else:

            raise

    if status not in (0, 1):

        raise Exception(stderr)

    f = open(out_file, 'wb')

    try:

        f.write(output)

    finally:

        f.close()

    return status