/brz/remove-bazaar

# Copyright (C) 2005, 2006 Canonical Ltd

# Copyright (C) 2005, 2008 Aaron Bentley, 2006 Michael Ellerman

#

# 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

"""Diff and patch functionality"""

import errno

import os

from subprocess import Popen, PIPE

import sys

from .errors import NoDiff3, BzrError

from .textfile import check_text_path

class PatchFailed(BzrError):

    _fmt = """Patch application failed"""

class PatchInvokeError(BzrError):

    _fmt = """Error invoking patch: %(errstr)s%(stderr)s"""

    internal_error = False

    def __init__(self, e, stderr=''):

        self.exception = e

        self.errstr = os.strerror(e.errno)

        self.stderr = '\n' + stderr

_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 as e:

        if e.errno == errno.ENOENT:

            raise NoDiff3

        else:

            raise

    if status not in (0, 1):

        raise Exception(stderr)

    with open(out_file, 'wb') as f:

        f.write(output)

    return status

def patch_tree(tree, patches, strip=0, reverse=False, dry_run=False,

               quiet=False, out=None):

    """Apply a patch to a tree.

    Args:

      tree: A MutableTree object

      patches: list of patches as bytes

      strip: Strip X segments of paths

      reverse: Apply reversal of patch

      dry_run: Dry run

    """

    return run_patch(tree.basedir, patches, strip, reverse, dry_run,

                     quiet, out=out)

def run_patch(directory, patches, strip=0, reverse=False, dry_run=False,

              quiet=False, _patch_cmd='patch', target_file=None, out=None):

    args = [_patch_cmd, '-d', directory, '-s', '-p%d' % strip, '-f']

    if quiet:

        args.append('--quiet')

    if sys.platform == "win32":

        args.append('--binary')

    if reverse:

        args.append('-R')

    if dry_run:

        if sys.platform.startswith('freebsd'):

            args.append('--check')

        else:

            args.append('--dry-run')

        stderr = PIPE

    else:

        stderr = None

    if target_file is not None:

        args.append(target_file)

    try:

        process = Popen(args, stdin=PIPE, stdout=PIPE, stderr=stderr)

    except OSError as e:

        raise PatchInvokeError(e)

    try:

        for patch in patches:

            process.stdin.write(bytes(patch))

        process.stdin.close()

    except IOError as e:

        raise PatchInvokeError(e, process.stderr.read())

    result = process.wait()

    if not dry_run:

        if out is not None:

            out.write(process.stdout.read())

        else:

            process.stdout.read()

    if result != 0:

        raise PatchFailed()

    return result