/brz/remove-bazaar

# Copyright (C) 2005-2014 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

import contextlib

import difflib

import os

import re

import sys

from .lazy_import import lazy_import

lazy_import(globals(), """

import errno

import patiencediff

import subprocess

import tempfile

from breezy import (

    controldir,

    osutils,

    textfile,

    timestamp,

    views,

    )

from breezy.workingtree import WorkingTree

from breezy.i18n import gettext

""")

from . import (

    errors,

    )

from .registry import (

    Registry,

    )

from .trace import mutter, note, warning

from .tree import FileTimestampUnavailable

DEFAULT_CONTEXT_AMOUNT = 3

# TODO: Rather than building a changeset object, we should probably

# invoke callbacks on an object.  That object can either accumulate a

# list, write them out directly, etc etc.

class _PrematchedMatcher(difflib.SequenceMatcher):

    """Allow SequenceMatcher operations to use predetermined blocks"""

    def __init__(self, matching_blocks):

        difflib.SequenceMatcher(self, None, None)

        self.matching_blocks = matching_blocks

        self.opcodes = None

def internal_diff(old_label, oldlines, new_label, newlines, to_file,

                  allow_binary=False, sequence_matcher=None,

                  path_encoding='utf8', context_lines=DEFAULT_CONTEXT_AMOUNT):

    # FIXME: difflib is wrong if there is no trailing newline.

    # The syntax used by patch seems to be "\ No newline at

    # end of file" following the last diff line from that

    # file.  This is not trivial to insert into the

    # unified_diff output and it might be better to just fix

    # or replace that function.

    # In the meantime we at least make sure the patch isn't

    # mangled.

    if allow_binary is False:

        textfile.check_text_lines(oldlines)

        textfile.check_text_lines(newlines)

    if sequence_matcher is None:

        sequence_matcher = patiencediff.PatienceSequenceMatcher

    ud = unified_diff_bytes(

        oldlines, newlines,

        fromfile=old_label.encode(path_encoding, 'replace'),

        tofile=new_label.encode(path_encoding, 'replace'),

        n=context_lines, sequencematcher=sequence_matcher)

    ud = list(ud)

    if len(ud) == 0:  # Identical contents, nothing to do

        return

    # work-around for difflib being too smart for its own good

    # if /dev/null is "1,0", patch won't recognize it as /dev/null

    if not oldlines:

        ud[2] = ud[2].replace(b'-1,0', b'-0,0')

    elif not newlines:

        ud[2] = ud[2].replace(b'+1,0', b'+0,0')

    for line in ud:

        to_file.write(line)

        if not line.endswith(b'\n'):

            to_file.write(b"\n\\ No newline at end of file\n")

    to_file.write(b'\n')

def unified_diff_bytes(a, b, fromfile=b'', tofile=b'', fromfiledate=b'',

                       tofiledate=b'', n=3, lineterm=b'\n', sequencematcher=None):

    r"""

    Compare two sequences of lines; generate the delta as a unified diff.

    Unified diffs are a compact way of showing line changes and a few

    lines of context.  The number of context lines is set by 'n' which

    defaults to three.

    By default, the diff control lines (those with ---, +++, or @@) are

    created with a trailing newline.  This is helpful so that inputs

    created from file.readlines() result in diffs that are suitable for

    file.writelines() since both the inputs and outputs have trailing

    newlines.

    For inputs that do not have trailing newlines, set the lineterm

    argument to "" so that the output will be uniformly newline free.

    The unidiff format normally has a header for filenames and modification

    times.  Any or all of these may be specified using strings for

    'fromfile', 'tofile', 'fromfiledate', and 'tofiledate'.  The modification

    times are normally expressed in the format returned by time.ctime().

    Example:

    >>> for line in bytes_unified_diff(b'one two three four'.split(),

    ...             b'zero one tree four'.split(), b'Original', b'Current',

    ...             b'Sat Jan 26 23:30:50 1991', b'Fri Jun 06 10:20:52 2003',

    ...             lineterm=b''):

    ...     print line

    --- Original Sat Jan 26 23:30:50 1991

    +++ Current Fri Jun 06 10:20:52 2003

    @@ -1,4 +1,4 @@

    +zero

     one

    -two

    -three

    +tree

     four

    """

    if sequencematcher is None:

        sequencematcher = difflib.SequenceMatcher

    if fromfiledate:

        fromfiledate = b'\t' + bytes(fromfiledate)

    if tofiledate:

        tofiledate = b'\t' + bytes(tofiledate)

    started = False

    for group in sequencematcher(None, a, b).get_grouped_opcodes(n):

        if not started:

            yield b'--- %s%s%s' % (fromfile, fromfiledate, lineterm)

            yield b'+++ %s%s%s' % (tofile, tofiledate, lineterm)

            started = True

        i1, i2, j1, j2 = group[0][1], group[-1][2], group[0][3], group[-1][4]

        yield b"@@ -%d,%d +%d,%d @@%s" % (i1 + 1, i2 - i1, j1 + 1, j2 - j1, lineterm)

        for tag, i1, i2, j1, j2 in group:

            if tag == 'equal':

                for line in a[i1:i2]:

                    yield b' ' + line

                continue

            if tag == 'replace' or tag == 'delete':

                for line in a[i1:i2]:

                    yield b'-' + line

            if tag == 'replace' or tag == 'insert':

                for line in b[j1:j2]:

                    yield b'+' + line

def _spawn_external_diff(diffcmd, capture_errors=True):

    """Spawn the external diff process, and return the child handle.

    :param diffcmd: The command list to spawn

    :param capture_errors: Capture stderr as well as setting LANG=C

        and LC_ALL=C. This lets us read and understand the output of diff,

        and respond to any errors.

    :return: A Popen object.

    """

    if capture_errors:

        # construct minimal environment

        env = {}

        path = os.environ.get('PATH')

        if path is not None:

            env['PATH'] = path

        env['LANGUAGE'] = 'C'   # on win32 only LANGUAGE has effect

        env['LANG'] = 'C'

        env['LC_ALL'] = 'C'

        stderr = subprocess.PIPE

    else:

        env = None

        stderr = None

    try:

        pipe = subprocess.Popen(diffcmd,

                                stdin=subprocess.PIPE,

                                stdout=subprocess.PIPE,

                                stderr=stderr,

                                env=env)

    except OSError as e:

        if e.errno == errno.ENOENT:

            raise errors.NoDiff(str(e))

        raise

    return pipe

# diff style options as of GNU diff v3.2

style_option_list = ['-c', '-C', '--context',

                     '-e', '--ed',

                     '-f', '--forward-ed',

                     '-q', '--brief',

                     '--normal',

                     '-n', '--rcs',

                     '-u', '-U', '--unified',

                     '-y', '--side-by-side',

                     '-D', '--ifdef']

def default_style_unified(diff_opts):

    """Default to unified diff style if alternative not specified in diff_opts.

        diff only allows one style to be specified; they don't override.

        Note that some of these take optargs, and the optargs can be

        directly appended to the options.

        This is only an approximate parser; it doesn't properly understand

        the grammar.

    :param diff_opts: List of options for external (GNU) diff.

    :return: List of options with default style=='unified'.

    """

    for s in style_option_list:

        for j in diff_opts:

            if j.startswith(s):

                break

        else:

            continue

        break

    else:

        diff_opts.append('-u')

    return diff_opts

def external_diff(old_label, oldlines, new_label, newlines, to_file,

                  diff_opts):

    """Display a diff by calling out to the external diff program."""

    # make sure our own output is properly ordered before the diff

    to_file.flush()

    oldtmp_fd, old_abspath = tempfile.mkstemp(prefix='brz-diff-old-')

    newtmp_fd, new_abspath = tempfile.mkstemp(prefix='brz-diff-new-')

    oldtmpf = os.fdopen(oldtmp_fd, 'wb')

    newtmpf = os.fdopen(newtmp_fd, 'wb')

    try:

        # TODO: perhaps a special case for comparing to or from the empty

        # sequence; can just use /dev/null on Unix

        # TODO: if either of the files being compared already exists as a

        # regular named file (e.g. in the working directory) then we can

        # compare directly to that, rather than copying it.

        oldtmpf.writelines(oldlines)

        newtmpf.writelines(newlines)

        oldtmpf.close()

        newtmpf.close()

        if not diff_opts:

            diff_opts = []

        if sys.platform == 'win32':

            # Popen doesn't do the proper encoding for external commands

            # Since we are dealing with an ANSI api, use mbcs encoding

            old_label = old_label.encode('mbcs')

            new_label = new_label.encode('mbcs')

        diffcmd = ['diff',

                   '--label', old_label,

                   old_abspath,

                   '--label', new_label,

                   new_abspath,

                   '--binary',

                   ]

        diff_opts = default_style_unified(diff_opts)

        if diff_opts:

            diffcmd.extend(diff_opts)

        pipe = _spawn_external_diff(diffcmd, capture_errors=True)

        out, err = pipe.communicate()

        rc = pipe.returncode

        # internal_diff() adds a trailing newline, add one here for consistency

        out += b'\n'

        if rc == 2:

            # 'diff' gives retcode == 2 for all sorts of errors

            # one of those is 'Binary files differ'.

            # Bad options could also be the problem.

            # 'Binary files' is not a real error, so we suppress that error.

            lang_c_out = out

            # Since we got here, we want to make sure to give an i18n error

            pipe = _spawn_external_diff(diffcmd, capture_errors=False)

            out, err = pipe.communicate()

            # Write out the new i18n diff response

            to_file.write(out + b'\n')

            if pipe.returncode != 2:

                raise errors.BzrError(

                    'external diff failed with exit code 2'

                    ' when run with LANG=C and LC_ALL=C,'

                    ' but not when run natively: %r' % (diffcmd,))

            first_line = lang_c_out.split(b'\n', 1)[0]

            # Starting with diffutils 2.8.4 the word "binary" was dropped.

            m = re.match(b'^(binary )?files.*differ$', first_line, re.I)

            if m is None:

                raise errors.BzrError('external diff failed with exit code 2;'

                                      ' command: %r' % (diffcmd,))

            else:

                # Binary files differ, just return

                return

        # If we got to here, we haven't written out the output of diff

        # do so now

        to_file.write(out)

        if rc not in (0, 1):

            # returns 1 if files differ; that's OK

            if rc < 0:

                msg = 'signal %d' % (-rc)

            else:

                msg = 'exit code %d' % rc

            raise errors.BzrError('external diff failed with %s; command: %r'

                                  % (msg, diffcmd))

    finally:

        oldtmpf.close()                 # and delete

        newtmpf.close()

        def cleanup(path):

            # Warn in case the file couldn't be deleted (in case windows still

            # holds the file open, but not if the files have already been

            # deleted)

            try:

                os.remove(path)

            except OSError as e:

                if e.errno not in (errno.ENOENT,):

                    warning('Failed to delete temporary file: %s %s', path, e)

        cleanup(old_abspath)

        cleanup(new_abspath)

def get_trees_and_branches_to_diff_locked(

        path_list, revision_specs, old_url, new_url, exit_stack, apply_view=True):

    """Get the trees and specific files to diff given a list of paths.

    This method works out the trees to be diff'ed and the files of

    interest within those trees.

    :param path_list:

        the list of arguments passed to the diff command

    :param revision_specs:

        Zero, one or two RevisionSpecs from the diff command line,

        saying what revisions to compare.

    :param old_url:

        The url of the old branch or tree. If None, the tree to use is

        taken from the first path, if any, or the current working tree.

    :param new_url:

        The url of the new branch or tree. If None, the tree to use is

        taken from the first path, if any, or the current working tree.

    :param exit_stack:

        an ExitStack object. get_trees_and_branches_to_diff

        will register cleanups that must be run to unlock the trees, etc.

    :param apply_view:

        if True and a view is set, apply the view or check that the paths

        are within it

    :returns:

        a tuple of (old_tree, new_tree, old_branch, new_branch,

        specific_files, extra_trees) where extra_trees is a sequence of

        additional trees to search in for file-ids.  The trees and branches

        will be read-locked until the cleanups registered via the exit_stack

        param are run.

    """

    # Get the old and new revision specs

    old_revision_spec = None

    new_revision_spec = None

    if revision_specs is not None:

        if len(revision_specs) > 0:

            old_revision_spec = revision_specs[0]

            if old_url is None:

                old_url = old_revision_spec.get_branch()

        if len(revision_specs) > 1:

            new_revision_spec = revision_specs[1]

            if new_url is None:

                new_url = new_revision_spec.get_branch()

    other_paths = []

    make_paths_wt_relative = True

    consider_relpath = True

    if path_list is None or len(path_list) == 0:

        # If no path is given, the current working tree is used

        default_location = u'.'

        consider_relpath = False

    elif old_url is not None and new_url is not None:

        other_paths = path_list

        make_paths_wt_relative = False

    else:

        default_location = path_list[0]

        other_paths = path_list[1:]

    def lock_tree_or_branch(wt, br):

        if wt is not None:

            exit_stack.enter_context(wt.lock_read())

        elif br is not None:

            exit_stack.enter_context(br.lock_read())

    # Get the old location

    specific_files = []

    if old_url is None:

        old_url = default_location

    working_tree, branch, relpath = \

        controldir.ControlDir.open_containing_tree_or_branch(old_url)

    lock_tree_or_branch(working_tree, branch)

    if consider_relpath and relpath != '':

        if working_tree is not None and apply_view:

            views.check_path_in_view(working_tree, relpath)

        specific_files.append(relpath)

    old_tree = _get_tree_to_diff(old_revision_spec, working_tree, branch)

    old_branch = branch

    # Get the new location

    if new_url is None:

        new_url = default_location

    if new_url != old_url:

        working_tree, branch, relpath = \

            controldir.ControlDir.open_containing_tree_or_branch(new_url)

        lock_tree_or_branch(working_tree, branch)

        if consider_relpath and relpath != '':

            if working_tree is not None and apply_view:

                views.check_path_in_view(working_tree, relpath)

            specific_files.append(relpath)

    new_tree = _get_tree_to_diff(new_revision_spec, working_tree, branch,

                                 basis_is_default=working_tree is None)

    new_branch = branch

    # Get the specific files (all files is None, no files is [])

    if make_paths_wt_relative and working_tree is not None:

        other_paths = working_tree.safe_relpath_files(

            other_paths,

            apply_view=apply_view)

    specific_files.extend(other_paths)

    if len(specific_files) == 0:

        specific_files = None

        if (working_tree is not None and working_tree.supports_views() and

                apply_view):

            view_files = working_tree.views.lookup_view()

            if view_files:

                specific_files = view_files

                view_str = views.view_display_str(view_files)

                note(gettext("*** Ignoring files outside view. View is %s") % view_str)

    # Get extra trees that ought to be searched for file-ids

    extra_trees = None

    if working_tree is not None and working_tree not in (old_tree, new_tree):

        extra_trees = (working_tree,)

    return (old_tree, new_tree, old_branch, new_branch,

            specific_files, extra_trees)

def _get_tree_to_diff(spec, tree=None, branch=None, basis_is_default=True):

    if branch is None and tree is not None:

        branch = tree.branch

    if spec is None or spec.spec is None:

        if basis_is_default:

            if tree is not None:

                return tree.basis_tree()

            else:

                return branch.basis_tree()

        else:

            return tree

    return spec.as_tree(branch)

def show_diff_trees(old_tree, new_tree, to_file, specific_files=None,

                    external_diff_options=None,

                    old_label='a/', new_label='b/',

                    extra_trees=None,

                    path_encoding='utf8',

                    using=None,

                    format_cls=None,

                    context=DEFAULT_CONTEXT_AMOUNT):

    """Show in text form the changes from one tree to another.

    :param to_file: The output stream.

    :param specific_files: Include only changes to these files - None for all

        changes.

    :param external_diff_options: If set, use an external GNU diff and pass

        these options.

    :param extra_trees: If set, more Trees to use for looking up file ids

    :param path_encoding: If set, the path will be encoded as specified,

        otherwise is supposed to be utf8

    :param format_cls: Formatter class (DiffTree subclass)

    """

    if context is None:

        context = DEFAULT_CONTEXT_AMOUNT

    if format_cls is None:

        format_cls = DiffTree

    with contextlib.ExitStack() as exit_stack:

        exit_stack.enter_context(old_tree.lock_read())

        if extra_trees is not None:

            for tree in extra_trees:

                exit_stack.enter_context(tree.lock_read())

        exit_stack.enter_context(new_tree.lock_read())

        differ = format_cls.from_trees_options(old_tree, new_tree, to_file,

                                               path_encoding,

                                               external_diff_options,

                                               old_label, new_label, using,

                                               context_lines=context)

        return differ.show_diff(specific_files, extra_trees)

def _patch_header_date(tree, path):

    """Returns a timestamp suitable for use in a patch header."""

    try:

        mtime = tree.get_file_mtime(path)

    except FileTimestampUnavailable:

        mtime = 0

    return timestamp.format_patch_date(mtime)

def get_executable_change(old_is_x, new_is_x):

    descr = {True: b"+x", False: b"-x", None: b"??"}

    if old_is_x != new_is_x:

        return [b"%s to %s" % (descr[old_is_x], descr[new_is_x],)]

    else:

        return []

class DiffPath(object):

    """Base type for command object that compare files"""

    # The type or contents of the file were unsuitable for diffing

    CANNOT_DIFF = 'CANNOT_DIFF'

    # The file has changed in a semantic way

    CHANGED = 'CHANGED'

    # The file content may have changed, but there is no semantic change

    UNCHANGED = 'UNCHANGED'

    def __init__(self, old_tree, new_tree, to_file, path_encoding='utf-8'):

        """Constructor.

        :param old_tree: The tree to show as the old tree in the comparison

        :param new_tree: The tree to show as new in the comparison

        :param to_file: The file to write comparison data to

        :param path_encoding: The character encoding to write paths in

        """

        self.old_tree = old_tree

        self.new_tree = new_tree

        self.to_file = to_file

        self.path_encoding = path_encoding

    def finish(self):

        pass

    @classmethod

    def from_diff_tree(klass, diff_tree):

        return klass(diff_tree.old_tree, diff_tree.new_tree,

                     diff_tree.to_file, diff_tree.path_encoding)

    @staticmethod

    def _diff_many(differs, old_path, new_path, old_kind, new_kind):

        for file_differ in differs:

            result = file_differ.diff(old_path, new_path, old_kind, new_kind)

            if result is not DiffPath.CANNOT_DIFF:

                return result

        else:

            return DiffPath.CANNOT_DIFF

class DiffKindChange(object):

    """Special differ for file kind changes.

    Represents kind change as deletion + creation.  Uses the other differs

    to do this.

    """

    def __init__(self, differs):

        self.differs = differs

    def finish(self):

        pass

    @classmethod

    def from_diff_tree(klass, diff_tree):

        return klass(diff_tree.differs)

    def diff(self, old_path, new_path, old_kind, new_kind):

        """Perform comparison

        :param old_path: Path of the file in the old tree

        :param new_path: Path of the file in the new tree

        :param old_kind: Old file-kind of the file

        :param new_kind: New file-kind of the file

        """

        if None in (old_kind, new_kind):

            return DiffPath.CANNOT_DIFF

        result = DiffPath._diff_many(

            self.differs, old_path, new_path, old_kind, None)

        if result is DiffPath.CANNOT_DIFF:

            return result

        return DiffPath._diff_many(

            self.differs, old_path, new_path, None, new_kind)

class DiffTreeReference(DiffPath):

    def diff(self, old_path, new_path, old_kind, new_kind):

        """Perform comparison between two tree references.  (dummy)

        """

        if 'tree-reference' not in (old_kind, new_kind):

            return self.CANNOT_DIFF

        if old_kind not in ('tree-reference', None):

            return self.CANNOT_DIFF

        if new_kind not in ('tree-reference', None):

            return self.CANNOT_DIFF

        return self.CHANGED

class DiffDirectory(DiffPath):

    def diff(self, old_path, new_path, old_kind, new_kind):

        """Perform comparison between two directories.  (dummy)

        """

        if 'directory' not in (old_kind, new_kind):

            return self.CANNOT_DIFF

        if old_kind not in ('directory', None):

            return self.CANNOT_DIFF

        if new_kind not in ('directory', None):

            return self.CANNOT_DIFF

        return self.CHANGED

class DiffSymlink(DiffPath):

    def diff(self, old_path, new_path, old_kind, new_kind):

        """Perform comparison between two symlinks

        :param old_path: Path of the file in the old tree

        :param new_path: Path of the file in the new tree

        :param old_kind: Old file-kind of the file

        :param new_kind: New file-kind of the file