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  • Committer: Vincent Ladeuil
  • Date: 2013-08-09 15:09:23 UTC
  • mto: This revision was merged to the branch mainline in revision 6587.
  • Revision ID: v.ladeuil+lp@free.fr-20130809150923-y71dusyorep0hbkt
Fix various typos in docstrings. Rename 'buffer' to 'buf' since it's now a python builtin function.

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bzrlib/diff.py
1
 
# -*- coding: UTF-8 -*-
2
 
 
 
1
# Copyright (C) 2005-2011 Canonical Ltd.
 
2
#
3
3
# This program is free software; you can redistribute it and/or modify
4
4
# it under the terms of the GNU General Public License as published by
5
5
# the Free Software Foundation; either version 2 of the License, or
6
6
# (at your option) any later version.
7
 
 
 
7
#
8
8
# This program is distributed in the hope that it will be useful,
9
9
# but WITHOUT ANY WARRANTY; without even the implied warranty of
10
10
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11
11
# GNU General Public License for more details.
12
 
 
 
12
#
13
13
# You should have received a copy of the GNU General Public License
14
14
# along with this program; if not, write to the Free Software
15
 
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
16
 
 
17
 
from bzrlib.trace import mutter
18
 
from bzrlib.errors import BzrError
19
 
from bzrlib.delta import compare_trees
 
15
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 
16
 
 
17
from __future__ import absolute_import
 
18
 
 
19
import difflib
 
20
import os
 
21
import re
 
22
import string
 
23
import sys
 
24
 
 
25
from bzrlib.lazy_import import lazy_import
 
26
lazy_import(globals(), """
 
27
import errno
 
28
import subprocess
 
29
import tempfile
 
30
 
 
31
from bzrlib import (
 
32
    cleanup,
 
33
    cmdline,
 
34
    controldir,
 
35
    errors,
 
36
    osutils,
 
37
    patiencediff,
 
38
    textfile,
 
39
    timestamp,
 
40
    views,
 
41
    )
 
42
 
 
43
from bzrlib.workingtree import WorkingTree
 
44
from bzrlib.i18n import gettext
 
45
""")
 
46
 
 
47
from bzrlib.registry import (
 
48
    Registry,
 
49
    )
 
50
from bzrlib.trace import mutter, note, warning
 
51
 
 
52
DEFAULT_CONTEXT_AMOUNT = 3
 
53
 
 
54
class AtTemplate(string.Template):
 
55
    """Templating class that uses @ instead of $."""
 
56
 
 
57
    delimiter = '@'
 
58
 
20
59
 
21
60
# TODO: Rather than building a changeset object, we should probably
22
61
# invoke callbacks on an object.  That object can either accumulate a
23
62
# list, write them out directly, etc etc.
24
63
 
25
 
def internal_diff(old_filename, oldlines, new_filename, newlines, to_file):
26
 
    import difflib
27
 
    
 
64
 
 
65
class _PrematchedMatcher(difflib.SequenceMatcher):
 
66
    """Allow SequenceMatcher operations to use predetermined blocks"""
 
67
 
 
68
    def __init__(self, matching_blocks):
 
69
        difflib.SequenceMatcher(self, None, None)
 
70
        self.matching_blocks = matching_blocks
 
71
        self.opcodes = None
 
72
 
 
73
 
 
74
def internal_diff(old_filename, oldlines, new_filename, newlines, to_file,
 
75
                  allow_binary=False, sequence_matcher=None,
 
76
                  path_encoding='utf8', context_lines=DEFAULT_CONTEXT_AMOUNT):
28
77
    # FIXME: difflib is wrong if there is no trailing newline.
29
78
    # The syntax used by patch seems to be "\ No newline at
30
79
    # end of file" following the last diff line from that
41
90
    if not oldlines and not newlines:
42
91
        return
43
92
 
44
 
    ud = difflib.unified_diff(oldlines, newlines,
45
 
                              fromfile=old_filename+'\t', 
46
 
                              tofile=new_filename+'\t')
 
93
    if allow_binary is False:
 
94
        textfile.check_text_lines(oldlines)
 
95
        textfile.check_text_lines(newlines)
 
96
 
 
97
    if sequence_matcher is None:
 
98
        sequence_matcher = patiencediff.PatienceSequenceMatcher
 
99
    ud = patiencediff.unified_diff(oldlines, newlines,
 
100
                      fromfile=old_filename.encode(path_encoding, 'replace'),
 
101
                      tofile=new_filename.encode(path_encoding, 'replace'),
 
102
                      n=context_lines, sequencematcher=sequence_matcher)
47
103
 
48
104
    ud = list(ud)
 
105
    if len(ud) == 0: # Identical contents, nothing to do
 
106
        return
49
107
    # work-around for difflib being too smart for its own good
50
108
    # if /dev/null is "1,0", patch won't recognize it as /dev/null
51
109
    if not oldlines:
52
110
        ud[2] = ud[2].replace('-1,0', '-0,0')
53
111
    elif not newlines:
54
112
        ud[2] = ud[2].replace('+1,0', '+0,0')
55
 
    # work around for difflib emitting random spaces after the label
56
 
    ud[0] = ud[0][:-2] + '\n'
57
 
    ud[1] = ud[1][:-2] + '\n'
58
113
 
59
114
    for line in ud:
60
115
        to_file.write(line)
61
116
        if not line.endswith('\n'):
62
117
            to_file.write("\n\\ No newline at end of file\n")
63
 
    print >>to_file
 
118
    to_file.write('\n')
 
119
 
 
120
 
 
121
def _spawn_external_diff(diffcmd, capture_errors=True):
 
122
    """Spawn the externall diff process, and return the child handle.
 
123
 
 
124
    :param diffcmd: The command list to spawn
 
125
    :param capture_errors: Capture stderr as well as setting LANG=C
 
126
        and LC_ALL=C. This lets us read and understand the output of diff,
 
127
        and respond to any errors.
 
128
    :return: A Popen object.
 
129
    """
 
130
    if capture_errors:
 
131
        # construct minimal environment
 
132
        env = {}
 
133
        path = os.environ.get('PATH')
 
134
        if path is not None:
 
135
            env['PATH'] = path
 
136
        env['LANGUAGE'] = 'C'   # on win32 only LANGUAGE has effect
 
137
        env['LANG'] = 'C'
 
138
        env['LC_ALL'] = 'C'
 
139
        stderr = subprocess.PIPE
 
140
    else:
 
141
        env = None
 
142
        stderr = None
 
143
 
 
144
    try:
 
145
        pipe = subprocess.Popen(diffcmd,
 
146
                                stdin=subprocess.PIPE,
 
147
                                stdout=subprocess.PIPE,
 
148
                                stderr=stderr,
 
149
                                env=env)
 
150
    except OSError, e:
 
151
        if e.errno == errno.ENOENT:
 
152
            raise errors.NoDiff(str(e))
 
153
        raise
 
154
 
 
155
    return pipe
64
156
 
65
157
 
66
158
def external_diff(old_filename, oldlines, new_filename, newlines, to_file,
67
159
                  diff_opts):
68
160
    """Display a diff by calling out to the external diff program."""
69
 
    import sys
70
 
    
71
 
    if to_file != sys.stdout:
72
 
        raise NotImplementedError("sorry, can't send external diff other than to stdout yet",
73
 
                                  to_file)
74
 
 
75
161
    # make sure our own output is properly ordered before the diff
76
162
    to_file.flush()
77
163
 
78
 
    from tempfile import NamedTemporaryFile
79
 
    import os
80
 
 
81
 
    oldtmpf = NamedTemporaryFile()
82
 
    newtmpf = NamedTemporaryFile()
 
164
    oldtmp_fd, old_abspath = tempfile.mkstemp(prefix='bzr-diff-old-')
 
165
    newtmp_fd, new_abspath = tempfile.mkstemp(prefix='bzr-diff-new-')
 
166
    oldtmpf = os.fdopen(oldtmp_fd, 'wb')
 
167
    newtmpf = os.fdopen(newtmp_fd, 'wb')
83
168
 
84
169
    try:
85
170
        # TODO: perhaps a special case for comparing to or from the empty
92
177
        oldtmpf.writelines(oldlines)
93
178
        newtmpf.writelines(newlines)
94
179
 
95
 
        oldtmpf.flush()
96
 
        newtmpf.flush()
 
180
        oldtmpf.close()
 
181
        newtmpf.close()
97
182
 
98
183
        if not diff_opts:
99
184
            diff_opts = []
 
185
        if sys.platform == 'win32':
 
186
            # Popen doesn't do the proper encoding for external commands
 
187
            # Since we are dealing with an ANSI api, use mbcs encoding
 
188
            old_filename = old_filename.encode('mbcs')
 
189
            new_filename = new_filename.encode('mbcs')
100
190
        diffcmd = ['diff',
101
 
                   '--label', old_filename+'\t',
102
 
                   oldtmpf.name,
103
 
                   '--label', new_filename+'\t',
104
 
                   newtmpf.name]
 
191
                   '--label', old_filename,
 
192
                   old_abspath,
 
193
                   '--label', new_filename,
 
194
                   new_abspath,
 
195
                   '--binary',
 
196
                  ]
105
197
 
106
198
        # diff only allows one style to be specified; they don't override.
107
199
        # note that some of these take optargs, and the optargs can be
123
215
            break
124
216
        else:
125
217
            diffcmd.append('-u')
126
 
                  
 
218
 
127
219
        if diff_opts:
128
220
            diffcmd.extend(diff_opts)
129
221
 
130
 
        rc = os.spawnvp(os.P_WAIT, 'diff', diffcmd)
131
 
        
132
 
        if rc != 0 and rc != 1:
 
222
        pipe = _spawn_external_diff(diffcmd, capture_errors=True)
 
223
        out,err = pipe.communicate()
 
224
        rc = pipe.returncode
 
225
 
 
226
        # internal_diff() adds a trailing newline, add one here for consistency
 
227
        out += '\n'
 
228
        if rc == 2:
 
229
            # 'diff' gives retcode == 2 for all sorts of errors
 
230
            # one of those is 'Binary files differ'.
 
231
            # Bad options could also be the problem.
 
232
            # 'Binary files' is not a real error, so we suppress that error.
 
233
            lang_c_out = out
 
234
 
 
235
            # Since we got here, we want to make sure to give an i18n error
 
236
            pipe = _spawn_external_diff(diffcmd, capture_errors=False)
 
237
            out, err = pipe.communicate()
 
238
 
 
239
            # Write out the new i18n diff response
 
240
            to_file.write(out+'\n')
 
241
            if pipe.returncode != 2:
 
242
                raise errors.BzrError(
 
243
                               'external diff failed with exit code 2'
 
244
                               ' when run with LANG=C and LC_ALL=C,'
 
245
                               ' but not when run natively: %r' % (diffcmd,))
 
246
 
 
247
            first_line = lang_c_out.split('\n', 1)[0]
 
248
            # Starting with diffutils 2.8.4 the word "binary" was dropped.
 
249
            m = re.match('^(binary )?files.*differ$', first_line, re.I)
 
250
            if m is None:
 
251
                raise errors.BzrError('external diff failed with exit code 2;'
 
252
                                      ' command: %r' % (diffcmd,))
 
253
            else:
 
254
                # Binary files differ, just return
 
255
                return
 
256
 
 
257
        # If we got to here, we haven't written out the output of diff
 
258
        # do so now
 
259
        to_file.write(out)
 
260
        if rc not in (0, 1):
133
261
            # returns 1 if files differ; that's OK
134
262
            if rc < 0:
135
263
                msg = 'signal %d' % (-rc)
136
264
            else:
137
265
                msg = 'exit code %d' % rc
138
 
                
139
 
            raise BzrError('external diff failed with %s; command: %r' % (rc, diffcmd))
 
266
 
 
267
            raise errors.BzrError('external diff failed with %s; command: %r'
 
268
                                  % (rc, diffcmd))
 
269
 
 
270
 
140
271
    finally:
141
272
        oldtmpf.close()                 # and delete
142
273
        newtmpf.close()
143
 
 
144
 
def show_diff(b, from_spec, specific_files, external_diff_options=None,
145
 
              revision2=None, output=None, b2=None):
146
 
    """Shortcut for showing the diff to the working tree.
147
 
 
148
 
    b
149
 
        Branch.
150
 
 
151
 
    revision
152
 
        None for 'basis tree', or otherwise the old revision to compare against.
153
 
    
154
 
    The more general form is show_diff_trees(), where the caller
155
 
    supplies any two trees.
 
274
        # Clean up. Warn in case the files couldn't be deleted
 
275
        # (in case windows still holds the file open, but not
 
276
        # if the files have already been deleted)
 
277
        try:
 
278
            os.remove(old_abspath)
 
279
        except OSError, e:
 
280
            if e.errno not in (errno.ENOENT,):
 
281
                warning('Failed to delete temporary file: %s %s',
 
282
                        old_abspath, e)
 
283
        try:
 
284
            os.remove(new_abspath)
 
285
        except OSError:
 
286
            if e.errno not in (errno.ENOENT,):
 
287
                warning('Failed to delete temporary file: %s %s',
 
288
                        new_abspath, e)
 
289
 
 
290
 
 
291
def get_trees_and_branches_to_diff_locked(
 
292
    path_list, revision_specs, old_url, new_url, add_cleanup, apply_view=True):
 
293
    """Get the trees and specific files to diff given a list of paths.
 
294
 
 
295
    This method works out the trees to be diff'ed and the files of
 
296
    interest within those trees.
 
297
 
 
298
    :param path_list:
 
299
        the list of arguments passed to the diff command
 
300
    :param revision_specs:
 
301
        Zero, one or two RevisionSpecs from the diff command line,
 
302
        saying what revisions to compare.
 
303
    :param old_url:
 
304
        The url of the old branch or tree. If None, the tree to use is
 
305
        taken from the first path, if any, or the current working tree.
 
306
    :param new_url:
 
307
        The url of the new branch or tree. If None, the tree to use is
 
308
        taken from the first path, if any, or the current working tree.
 
309
    :param add_cleanup:
 
310
        a callable like Command.add_cleanup.  get_trees_and_branches_to_diff
 
311
        will register cleanups that must be run to unlock the trees, etc.
 
312
    :param apply_view:
 
313
        if True and a view is set, apply the view or check that the paths
 
314
        are within it
 
315
    :returns:
 
316
        a tuple of (old_tree, new_tree, old_branch, new_branch,
 
317
        specific_files, extra_trees) where extra_trees is a sequence of
 
318
        additional trees to search in for file-ids.  The trees and branches
 
319
        will be read-locked until the cleanups registered via the add_cleanup
 
320
        param are run.
156
321
    """
157
 
    if output is None:
158
 
        import sys
159
 
        output = sys.stdout
160
 
 
161
 
    if from_spec is None:
162
 
        if b2 is None:
163
 
            old_tree = b.basis_tree()
164
 
        else:
165
 
            old_tree = b.working_tree()
166
 
    else:
167
 
        old_tree = b.repository.revision_tree(from_spec.in_history(b).rev_id)
168
 
 
169
 
    if revision2 is None:
170
 
        if b2 is None:
171
 
            new_tree = b.working_tree()
172
 
        else:
173
 
            new_tree = b2.working_tree()
174
 
    else:
175
 
        new_tree = b.repository.revision_tree(revision2.in_history(b).rev_id)
176
 
 
177
 
    return show_diff_trees(old_tree, new_tree, output, specific_files,
178
 
                           external_diff_options)
179
 
 
 
322
    # Get the old and new revision specs
 
323
    old_revision_spec = None
 
324
    new_revision_spec = None
 
325
    if revision_specs is not None:
 
326
        if len(revision_specs) > 0:
 
327
            old_revision_spec = revision_specs[0]
 
328
            if old_url is None:
 
329
                old_url = old_revision_spec.get_branch()
 
330
        if len(revision_specs) > 1:
 
331
            new_revision_spec = revision_specs[1]
 
332
            if new_url is None:
 
333
                new_url = new_revision_spec.get_branch()
 
334
 
 
335
    other_paths = []
 
336
    make_paths_wt_relative = True
 
337
    consider_relpath = True
 
338
    if path_list is None or len(path_list) == 0:
 
339
        # If no path is given, the current working tree is used
 
340
        default_location = u'.'
 
341
        consider_relpath = False
 
342
    elif old_url is not None and new_url is not None:
 
343
        other_paths = path_list
 
344
        make_paths_wt_relative = False
 
345
    else:
 
346
        default_location = path_list[0]
 
347
        other_paths = path_list[1:]
 
348
 
 
349
    def lock_tree_or_branch(wt, br):
 
350
        if wt is not None:
 
351
            wt.lock_read()
 
352
            add_cleanup(wt.unlock)
 
353
        elif br is not None:
 
354
            br.lock_read()
 
355
            add_cleanup(br.unlock)
 
356
 
 
357
    # Get the old location
 
358
    specific_files = []
 
359
    if old_url is None:
 
360
        old_url = default_location
 
361
    working_tree, branch, relpath = \
 
362
        controldir.ControlDir.open_containing_tree_or_branch(old_url)
 
363
    lock_tree_or_branch(working_tree, branch)
 
364
    if consider_relpath and relpath != '':
 
365
        if working_tree is not None and apply_view:
 
366
            views.check_path_in_view(working_tree, relpath)
 
367
        specific_files.append(relpath)
 
368
    old_tree = _get_tree_to_diff(old_revision_spec, working_tree, branch)
 
369
    old_branch = branch
 
370
 
 
371
    # Get the new location
 
372
    if new_url is None:
 
373
        new_url = default_location
 
374
    if new_url != old_url:
 
375
        working_tree, branch, relpath = \
 
376
            controldir.ControlDir.open_containing_tree_or_branch(new_url)
 
377
        lock_tree_or_branch(working_tree, branch)
 
378
        if consider_relpath and relpath != '':
 
379
            if working_tree is not None and apply_view:
 
380
                views.check_path_in_view(working_tree, relpath)
 
381
            specific_files.append(relpath)
 
382
    new_tree = _get_tree_to_diff(new_revision_spec, working_tree, branch,
 
383
        basis_is_default=working_tree is None)
 
384
    new_branch = branch
 
385
 
 
386
    # Get the specific files (all files is None, no files is [])
 
387
    if make_paths_wt_relative and working_tree is not None:
 
388
        other_paths = working_tree.safe_relpath_files(
 
389
            other_paths,
 
390
            apply_view=apply_view)
 
391
    specific_files.extend(other_paths)
 
392
    if len(specific_files) == 0:
 
393
        specific_files = None
 
394
        if (working_tree is not None and working_tree.supports_views()
 
395
            and apply_view):
 
396
            view_files = working_tree.views.lookup_view()
 
397
            if view_files:
 
398
                specific_files = view_files
 
399
                view_str = views.view_display_str(view_files)
 
400
                note(gettext("*** Ignoring files outside view. View is %s") % view_str)
 
401
 
 
402
    # Get extra trees that ought to be searched for file-ids
 
403
    extra_trees = None
 
404
    if working_tree is not None and working_tree not in (old_tree, new_tree):
 
405
        extra_trees = (working_tree,)
 
406
    return (old_tree, new_tree, old_branch, new_branch,
 
407
            specific_files, extra_trees)
 
408
 
 
409
 
 
410
def _get_tree_to_diff(spec, tree=None, branch=None, basis_is_default=True):
 
411
    if branch is None and tree is not None:
 
412
        branch = tree.branch
 
413
    if spec is None or spec.spec is None:
 
414
        if basis_is_default:
 
415
            if tree is not None:
 
416
                return tree.basis_tree()
 
417
            else:
 
418
                return branch.basis_tree()
 
419
        else:
 
420
            return tree
 
421
    return spec.as_tree(branch)
180
422
 
181
423
 
182
424
def show_diff_trees(old_tree, new_tree, to_file, specific_files=None,
183
 
                    external_diff_options=None):
 
425
                    external_diff_options=None,
 
426
                    old_label='a/', new_label='b/',
 
427
                    extra_trees=None,
 
428
                    path_encoding='utf8',
 
429
                    using=None,
 
430
                    format_cls=None,
 
431
                    context=DEFAULT_CONTEXT_AMOUNT):
184
432
    """Show in text form the changes from one tree to another.
185
433
 
186
 
    to_files
187
 
        If set, include only changes to these files.
188
 
 
189
 
    external_diff_options
190
 
        If set, use an external GNU diff and pass these options.
191
 
    """
192
 
 
193
 
    # TODO: Options to control putting on a prefix or suffix, perhaps as a format string
194
 
    old_label = ''
195
 
    new_label = ''
196
 
 
197
 
    DEVNULL = '/dev/null'
198
 
    # Windows users, don't panic about this filename -- it is a
199
 
    # special signal to GNU patch that the file should be created or
200
 
    # deleted respectively.
201
 
 
202
 
    # TODO: Generation of pseudo-diffs for added/deleted files could
203
 
    # be usefully made into a much faster special case.
204
 
 
205
 
    if external_diff_options:
206
 
        assert isinstance(external_diff_options, basestring)
207
 
        opts = external_diff_options.split()
208
 
        def diff_file(olab, olines, nlab, nlines, to_file):
209
 
            external_diff(olab, olines, nlab, nlines, to_file, opts)
210
 
    else:
211
 
        diff_file = internal_diff
212
 
    
213
 
 
214
 
    delta = compare_trees(old_tree, new_tree, want_unchanged=False,
215
 
                          specific_files=specific_files)
216
 
 
217
 
    has_changes = 0
218
 
    for path, file_id, kind in delta.removed:
219
 
        has_changes = 1
220
 
        print >>to_file, '=== removed %s %r' % (kind, path)
221
 
        old_tree.inventory[file_id].diff(diff_file, old_label + path, old_tree,
222
 
                                         DEVNULL, None, None, to_file)
223
 
    for path, file_id, kind in delta.added:
224
 
        has_changes = 1
225
 
        print >>to_file, '=== added %s %r' % (kind, path)
226
 
        new_tree.inventory[file_id].diff(diff_file, new_label + path, new_tree,
227
 
                                         DEVNULL, None, None, to_file, 
228
 
                                         reverse=True)
229
 
    for (old_path, new_path, file_id, kind,
230
 
         text_modified, meta_modified) in delta.renamed:
231
 
        has_changes = 1
232
 
        prop_str = get_prop_change(meta_modified)
233
 
        print >>to_file, '=== renamed %s %r => %r%s' % (
234
 
                          kind, old_path, new_path, prop_str)
235
 
        _maybe_diff_file_or_symlink(old_label, old_path, old_tree, file_id,
236
 
                                    new_label, new_path, new_tree,
237
 
                                    text_modified, kind, to_file, diff_file)
238
 
    for path, file_id, kind, text_modified, meta_modified in delta.modified:
239
 
        has_changes = 1
240
 
        prop_str = get_prop_change(meta_modified)
241
 
        print >>to_file, '=== modified %s %r%s' % (kind, path, prop_str)
242
 
        if text_modified:
243
 
            _maybe_diff_file_or_symlink(old_label, path, old_tree, file_id,
244
 
                                        new_label, path, new_tree,
245
 
                                        True, kind, to_file, diff_file)
246
 
    return has_changes
247
 
    
248
 
 
249
 
def get_prop_change(meta_modified):
250
 
    if meta_modified:
251
 
        return " (properties changed)"
252
 
    else:
253
 
        return  ""
254
 
 
255
 
 
256
 
def _maybe_diff_file_or_symlink(old_label, old_path, old_tree, file_id,
257
 
                                new_label, new_path, new_tree, text_modified,
258
 
                                kind, to_file, diff_file):
259
 
    if text_modified:
260
 
        new_entry = new_tree.inventory[file_id]
261
 
        old_tree.inventory[file_id].diff(diff_file,
262
 
                                         old_label + old_path, old_tree,
263
 
                                         new_label + new_path, new_entry, 
264
 
                                         new_tree, to_file)
 
434
    :param to_file: The output stream.
 
435
    :param specific_files: Include only changes to these files - None for all
 
436
        changes.
 
437
    :param external_diff_options: If set, use an external GNU diff and pass 
 
438
        these options.
 
439
    :param extra_trees: If set, more Trees to use for looking up file ids
 
440
    :param path_encoding: If set, the path will be encoded as specified, 
 
441
        otherwise is supposed to be utf8
 
442
    :param format_cls: Formatter class (DiffTree subclass)
 
443
    """
 
444
    if context is None:
 
445
        context = DEFAULT_CONTEXT_AMOUNT
 
446
    if format_cls is None:
 
447
        format_cls = DiffTree
 
448
    old_tree.lock_read()
 
449
    try:
 
450
        if extra_trees is not None:
 
451
            for tree in extra_trees:
 
452
                tree.lock_read()
 
453
        new_tree.lock_read()
 
454
        try:
 
455
            differ = format_cls.from_trees_options(old_tree, new_tree, to_file,
 
456
                                                   path_encoding,
 
457
                                                   external_diff_options,
 
458
                                                   old_label, new_label, using,
 
459
                                                   context_lines=context)
 
460
            return differ.show_diff(specific_files, extra_trees)
 
461
        finally:
 
462
            new_tree.unlock()
 
463
            if extra_trees is not None:
 
464
                for tree in extra_trees:
 
465
                    tree.unlock()
 
466
    finally:
 
467
        old_tree.unlock()
 
468
 
 
469
 
 
470
def _patch_header_date(tree, file_id, path):
 
471
    """Returns a timestamp suitable for use in a patch header."""
 
472
    try:
 
473
        mtime = tree.get_file_mtime(file_id, path)
 
474
    except errors.FileTimestampUnavailable:
 
475
        mtime = 0
 
476
    return timestamp.format_patch_date(mtime)
 
477
 
 
478
 
 
479
def get_executable_change(old_is_x, new_is_x):
 
480
    descr = { True:"+x", False:"-x", None:"??" }
 
481
    if old_is_x != new_is_x:
 
482
        return ["%s to %s" % (descr[old_is_x], descr[new_is_x],)]
 
483
    else:
 
484
        return []
 
485
 
 
486
 
 
487
class DiffPath(object):
 
488
    """Base type for command object that compare files"""
 
489
 
 
490
    # The type or contents of the file were unsuitable for diffing
 
491
    CANNOT_DIFF = 'CANNOT_DIFF'
 
492
    # The file has changed in a semantic way
 
493
    CHANGED = 'CHANGED'
 
494
    # The file content may have changed, but there is no semantic change
 
495
    UNCHANGED = 'UNCHANGED'
 
496
 
 
497
    def __init__(self, old_tree, new_tree, to_file, path_encoding='utf-8'):
 
498
        """Constructor.
 
499
 
 
500
        :param old_tree: The tree to show as the old tree in the comparison
 
501
        :param new_tree: The tree to show as new in the comparison
 
502
        :param to_file: The file to write comparison data to
 
503
        :param path_encoding: The character encoding to write paths in
 
504
        """
 
505
        self.old_tree = old_tree
 
506
        self.new_tree = new_tree
 
507
        self.to_file = to_file
 
508
        self.path_encoding = path_encoding
 
509
 
 
510
    def finish(self):
 
511
        pass
 
512
 
 
513
    @classmethod
 
514
    def from_diff_tree(klass, diff_tree):
 
515
        return klass(diff_tree.old_tree, diff_tree.new_tree,
 
516
                     diff_tree.to_file, diff_tree.path_encoding)
 
517
 
 
518
    @staticmethod
 
519
    def _diff_many(differs, file_id, old_path, new_path, old_kind, new_kind):
 
520
        for file_differ in differs:
 
521
            result = file_differ.diff(file_id, old_path, new_path, old_kind,
 
522
                                      new_kind)
 
523
            if result is not DiffPath.CANNOT_DIFF:
 
524
                return result
 
525
        else:
 
526
            return DiffPath.CANNOT_DIFF
 
527
 
 
528
 
 
529
class DiffKindChange(object):
 
530
    """Special differ for file kind changes.
 
531
 
 
532
    Represents kind change as deletion + creation.  Uses the other differs
 
533
    to do this.
 
534
    """
 
535
    def __init__(self, differs):
 
536
        self.differs = differs
 
537
 
 
538
    def finish(self):
 
539
        pass
 
540
 
 
541
    @classmethod
 
542
    def from_diff_tree(klass, diff_tree):
 
543
        return klass(diff_tree.differs)
 
544
 
 
545
    def diff(self, file_id, old_path, new_path, old_kind, new_kind):
 
546
        """Perform comparison
 
547
 
 
548
        :param file_id: The file_id of the file to compare
 
549
        :param old_path: Path of the file in the old tree
 
550
        :param new_path: Path of the file in the new tree
 
551
        :param old_kind: Old file-kind of the file
 
552
        :param new_kind: New file-kind of the file
 
553
        """
 
554
        if None in (old_kind, new_kind):
 
555
            return DiffPath.CANNOT_DIFF
 
556
        result = DiffPath._diff_many(self.differs, file_id, old_path,
 
557
                                       new_path, old_kind, None)
 
558
        if result is DiffPath.CANNOT_DIFF:
 
559
            return result
 
560
        return DiffPath._diff_many(self.differs, file_id, old_path, new_path,
 
561
                                     None, new_kind)
 
562
 
 
563
 
 
564
class DiffDirectory(DiffPath):
 
565
 
 
566
    def diff(self, file_id, old_path, new_path, old_kind, new_kind):
 
567
        """Perform comparison between two directories.  (dummy)
 
568
 
 
569
        """
 
570
        if 'directory' not in (old_kind, new_kind):
 
571
            return self.CANNOT_DIFF
 
572
        if old_kind not in ('directory', None):
 
573
            return self.CANNOT_DIFF
 
574
        if new_kind not in ('directory', None):
 
575
            return self.CANNOT_DIFF
 
576
        return self.CHANGED
 
577
 
 
578
 
 
579
class DiffSymlink(DiffPath):
 
580
 
 
581
    def diff(self, file_id, old_path, new_path, old_kind, new_kind):
 
582
        """Perform comparison between two symlinks
 
583
 
 
584
        :param file_id: The file_id of the file to compare
 
585
        :param old_path: Path of the file in the old tree
 
586
        :param new_path: Path of the file in the new tree
 
587
        :param old_kind: Old file-kind of the file
 
588
        :param new_kind: New file-kind of the file
 
589
        """
 
590
        if 'symlink' not in (old_kind, new_kind):
 
591
            return self.CANNOT_DIFF
 
592
        if old_kind == 'symlink':
 
593
            old_target = self.old_tree.get_symlink_target(file_id)
 
594
        elif old_kind is None:
 
595
            old_target = None
 
596
        else:
 
597
            return self.CANNOT_DIFF
 
598
        if new_kind == 'symlink':
 
599
            new_target = self.new_tree.get_symlink_target(file_id)
 
600
        elif new_kind is None:
 
601
            new_target = None
 
602
        else:
 
603
            return self.CANNOT_DIFF
 
604
        return self.diff_symlink(old_target, new_target)
 
605
 
 
606
    def diff_symlink(self, old_target, new_target):
 
607
        if old_target is None:
 
608
            self.to_file.write('=== target is %r\n' % new_target)
 
609
        elif new_target is None:
 
610
            self.to_file.write('=== target was %r\n' % old_target)
 
611
        else:
 
612
            self.to_file.write('=== target changed %r => %r\n' %
 
613
                              (old_target, new_target))
 
614
        return self.CHANGED
 
615
 
 
616
 
 
617
class DiffText(DiffPath):
 
618
 
 
619
    # GNU Patch uses the epoch date to detect files that are being added
 
620
    # or removed in a diff.
 
621
    EPOCH_DATE = '1970-01-01 00:00:00 +0000'
 
622
 
 
623
    def __init__(self, old_tree, new_tree, to_file, path_encoding='utf-8', 
 
624
                 old_label='', new_label='', text_differ=internal_diff, 
 
625
                 context_lines=DEFAULT_CONTEXT_AMOUNT):
 
626
        DiffPath.__init__(self, old_tree, new_tree, to_file, path_encoding)
 
627
        self.text_differ = text_differ
 
628
        self.old_label = old_label
 
629
        self.new_label = new_label
 
630
        self.path_encoding = path_encoding
 
631
        self.context_lines = context_lines
 
632
 
 
633
    def diff(self, file_id, old_path, new_path, old_kind, new_kind):
 
634
        """Compare two files in unified diff format
 
635
 
 
636
        :param file_id: The file_id of the file to compare
 
637
        :param old_path: Path of the file in the old tree
 
638
        :param new_path: Path of the file in the new tree
 
639
        :param old_kind: Old file-kind of the file
 
640
        :param new_kind: New file-kind of the file
 
641
        """
 
642
        if 'file' not in (old_kind, new_kind):
 
643
            return self.CANNOT_DIFF
 
644
        from_file_id = to_file_id = file_id
 
645
        if old_kind == 'file':
 
646
            old_date = _patch_header_date(self.old_tree, file_id, old_path)
 
647
        elif old_kind is None:
 
648
            old_date = self.EPOCH_DATE
 
649
            from_file_id = None
 
650
        else:
 
651
            return self.CANNOT_DIFF
 
652
        if new_kind == 'file':
 
653
            new_date = _patch_header_date(self.new_tree, file_id, new_path)
 
654
        elif new_kind is None:
 
655
            new_date = self.EPOCH_DATE
 
656
            to_file_id = None
 
657
        else:
 
658
            return self.CANNOT_DIFF
 
659
        from_label = '%s%s\t%s' % (self.old_label, old_path, old_date)
 
660
        to_label = '%s%s\t%s' % (self.new_label, new_path, new_date)
 
661
        return self.diff_text(from_file_id, to_file_id, from_label, to_label,
 
662
            old_path, new_path)
 
663
 
 
664
    def diff_text(self, from_file_id, to_file_id, from_label, to_label,
 
665
        from_path=None, to_path=None):
 
666
        """Diff the content of given files in two trees
 
667
 
 
668
        :param from_file_id: The id of the file in the from tree.  If None,
 
669
            the file is not present in the from tree.
 
670
        :param to_file_id: The id of the file in the to tree.  This may refer
 
671
            to a different file from from_file_id.  If None,
 
672
            the file is not present in the to tree.
 
673
        :param from_path: The path in the from tree or None if unknown.
 
674
        :param to_path: The path in the to tree or None if unknown.
 
675
        """
 
676
        def _get_text(tree, file_id, path):
 
677
            if file_id is not None:
 
678
                return tree.get_file_lines(file_id, path)
 
679
            else:
 
680
                return []
 
681
        try:
 
682
            from_text = _get_text(self.old_tree, from_file_id, from_path)
 
683
            to_text = _get_text(self.new_tree, to_file_id, to_path)
 
684
            self.text_differ(from_label, from_text, to_label, to_text,
 
685
                             self.to_file, path_encoding=self.path_encoding,
 
686
                             context_lines=self.context_lines)
 
687
        except errors.BinaryFile:
 
688
            self.to_file.write(
 
689
                  ("Binary files %s and %s differ\n" %
 
690
                  (from_label, to_label)).encode(self.path_encoding,'replace'))
 
691
        return self.CHANGED
 
692
 
 
693
 
 
694
class DiffFromTool(DiffPath):
 
695
 
 
696
    def __init__(self, command_template, old_tree, new_tree, to_file,
 
697
                 path_encoding='utf-8'):
 
698
        DiffPath.__init__(self, old_tree, new_tree, to_file, path_encoding)
 
699
        self.command_template = command_template
 
700
        self._root = osutils.mkdtemp(prefix='bzr-diff-')
 
701
 
 
702
    @classmethod
 
703
    def from_string(klass, command_string, old_tree, new_tree, to_file,
 
704
                    path_encoding='utf-8'):
 
705
        command_template = cmdline.split(command_string)
 
706
        if '@' not in command_string:
 
707
            command_template.extend(['@old_path', '@new_path'])
 
708
        return klass(command_template, old_tree, new_tree, to_file,
 
709
                     path_encoding)
 
710
 
 
711
    @classmethod
 
712
    def make_from_diff_tree(klass, command_string, external_diff_options=None):
 
713
        def from_diff_tree(diff_tree):
 
714
            full_command_string = [command_string]
 
715
            if external_diff_options is not None:
 
716
                full_command_string += ' ' + external_diff_options
 
717
            return klass.from_string(full_command_string, diff_tree.old_tree,
 
718
                                     diff_tree.new_tree, diff_tree.to_file)
 
719
        return from_diff_tree
 
720
 
 
721
    def _get_command(self, old_path, new_path):
 
722
        my_map = {'old_path': old_path, 'new_path': new_path}
 
723
        command = [AtTemplate(t).substitute(my_map) for t in
 
724
                   self.command_template]
 
725
        if sys.platform == 'win32': # Popen doesn't accept unicode on win32
 
726
            command_encoded = []
 
727
            for c in command:
 
728
                if isinstance(c, unicode):
 
729
                    command_encoded.append(c.encode('mbcs'))
 
730
                else:
 
731
                    command_encoded.append(c)
 
732
            return command_encoded
 
733
        else:
 
734
            return command
 
735
 
 
736
    def _execute(self, old_path, new_path):
 
737
        command = self._get_command(old_path, new_path)
 
738
        try:
 
739
            proc = subprocess.Popen(command, stdout=subprocess.PIPE,
 
740
                                    cwd=self._root)
 
741
        except OSError, e:
 
742
            if e.errno == errno.ENOENT:
 
743
                raise errors.ExecutableMissing(command[0])
 
744
            else:
 
745
                raise
 
746
        self.to_file.write(proc.stdout.read())
 
747
        return proc.wait()
 
748
 
 
749
    def _try_symlink_root(self, tree, prefix):
 
750
        if (getattr(tree, 'abspath', None) is None
 
751
            or not osutils.host_os_dereferences_symlinks()):
 
752
            return False
 
753
        try:
 
754
            os.symlink(tree.abspath(''), osutils.pathjoin(self._root, prefix))
 
755
        except OSError, e:
 
756
            if e.errno != errno.EEXIST:
 
757
                raise
 
758
        return True
 
759
 
 
760
    @staticmethod
 
761
    def _fenc():
 
762
        """Returns safe encoding for passing file path to diff tool"""
 
763
        if sys.platform == 'win32':
 
764
            return 'mbcs'
 
765
        else:
 
766
            # Don't fallback to 'utf-8' because subprocess may not be able to
 
767
            # handle utf-8 correctly when locale is not utf-8.
 
768
            return sys.getfilesystemencoding() or 'ascii'
 
769
 
 
770
    def _is_safepath(self, path):
 
771
        """Return true if `path` may be able to pass to subprocess."""
 
772
        fenc = self._fenc()
 
773
        try:
 
774
            return path == path.encode(fenc).decode(fenc)
 
775
        except UnicodeError:
 
776
            return False
 
777
 
 
778
    def _safe_filename(self, prefix, relpath):
 
779
        """Replace unsafe character in `relpath` then join `self._root`,
 
780
        `prefix` and `relpath`."""
 
781
        fenc = self._fenc()
 
782
        # encoded_str.replace('?', '_') may break multibyte char.
 
783
        # So we should encode, decode, then replace(u'?', u'_')
 
784
        relpath_tmp = relpath.encode(fenc, 'replace').decode(fenc, 'replace')
 
785
        relpath_tmp = relpath_tmp.replace(u'?', u'_')
 
786
        return osutils.pathjoin(self._root, prefix, relpath_tmp)
 
787
 
 
788
    def _write_file(self, file_id, tree, prefix, relpath, force_temp=False,
 
789
                    allow_write=False):
 
790
        if not force_temp and isinstance(tree, WorkingTree):
 
791
            full_path = tree.abspath(tree.id2path(file_id))
 
792
            if self._is_safepath(full_path):
 
793
                return full_path
 
794
 
 
795
        full_path = self._safe_filename(prefix, relpath)
 
796
        if not force_temp and self._try_symlink_root(tree, prefix):
 
797
            return full_path
 
798
        parent_dir = osutils.dirname(full_path)
 
799
        try:
 
800
            os.makedirs(parent_dir)
 
801
        except OSError, e:
 
802
            if e.errno != errno.EEXIST:
 
803
                raise
 
804
        source = tree.get_file(file_id, relpath)
 
805
        try:
 
806
            target = open(full_path, 'wb')
 
807
            try:
 
808
                osutils.pumpfile(source, target)
 
809
            finally:
 
810
                target.close()
 
811
        finally:
 
812
            source.close()
 
813
        try:
 
814
            mtime = tree.get_file_mtime(file_id)
 
815
        except errors.FileTimestampUnavailable:
 
816
            pass
 
817
        else:
 
818
            os.utime(full_path, (mtime, mtime))
 
819
        if not allow_write:
 
820
            osutils.make_readonly(full_path)
 
821
        return full_path
 
822
 
 
823
    def _prepare_files(self, file_id, old_path, new_path, force_temp=False,
 
824
                       allow_write_new=False):
 
825
        old_disk_path = self._write_file(file_id, self.old_tree, 'old',
 
826
                                         old_path, force_temp)
 
827
        new_disk_path = self._write_file(file_id, self.new_tree, 'new',
 
828
                                         new_path, force_temp,
 
829
                                         allow_write=allow_write_new)
 
830
        return old_disk_path, new_disk_path
 
831
 
 
832
    def finish(self):
 
833
        try:
 
834
            osutils.rmtree(self._root)
 
835
        except OSError, e:
 
836
            if e.errno != errno.ENOENT:
 
837
                mutter("The temporary directory \"%s\" was not "
 
838
                        "cleanly removed: %s." % (self._root, e))
 
839
 
 
840
    def diff(self, file_id, old_path, new_path, old_kind, new_kind):
 
841
        if (old_kind, new_kind) != ('file', 'file'):
 
842
            return DiffPath.CANNOT_DIFF
 
843
        (old_disk_path, new_disk_path) = self._prepare_files(
 
844
                                                file_id, old_path, new_path)
 
845
        self._execute(old_disk_path, new_disk_path)
 
846
 
 
847
    def edit_file(self, file_id):
 
848
        """Use this tool to edit a file.
 
849
 
 
850
        A temporary copy will be edited, and the new contents will be
 
851
        returned.
 
852
 
 
853
        :param file_id: The id of the file to edit.
 
854
        :return: The new contents of the file.
 
855
        """
 
856
        old_path = self.old_tree.id2path(file_id)
 
857
        new_path = self.new_tree.id2path(file_id)
 
858
        old_abs_path, new_abs_path = self._prepare_files(
 
859
                                            file_id, old_path, new_path,
 
860
                                            allow_write_new=True,
 
861
                                            force_temp=True)
 
862
        command = self._get_command(old_abs_path, new_abs_path)
 
863
        subprocess.call(command, cwd=self._root)
 
864
        new_file = open(new_abs_path, 'rb')
 
865
        try:
 
866
            return new_file.read()
 
867
        finally:
 
868
            new_file.close()
 
869
 
 
870
 
 
871
class DiffTree(object):
 
872
    """Provides textual representations of the difference between two trees.
 
873
 
 
874
    A DiffTree examines two trees and where a file-id has altered
 
875
    between them, generates a textual representation of the difference.
 
876
    DiffTree uses a sequence of DiffPath objects which are each
 
877
    given the opportunity to handle a given altered fileid. The list
 
878
    of DiffPath objects can be extended globally by appending to
 
879
    DiffTree.diff_factories, or for a specific diff operation by
 
880
    supplying the extra_factories option to the appropriate method.
 
881
    """
 
882
 
 
883
    # list of factories that can provide instances of DiffPath objects
 
884
    # may be extended by plugins.
 
885
    diff_factories = [DiffSymlink.from_diff_tree,
 
886
                      DiffDirectory.from_diff_tree]
 
887
 
 
888
    def __init__(self, old_tree, new_tree, to_file, path_encoding='utf-8',
 
889
                 diff_text=None, extra_factories=None):
 
890
        """Constructor
 
891
 
 
892
        :param old_tree: Tree to show as old in the comparison
 
893
        :param new_tree: Tree to show as new in the comparison
 
894
        :param to_file: File to write comparision to
 
895
        :param path_encoding: Character encoding to write paths in
 
896
        :param diff_text: DiffPath-type object to use as a last resort for
 
897
            diffing text files.
 
898
        :param extra_factories: Factories of DiffPaths to try before any other
 
899
            DiffPaths"""
 
900
        if diff_text is None:
 
901
            diff_text = DiffText(old_tree, new_tree, to_file, path_encoding,
 
902
                                 '', '',  internal_diff)
 
903
        self.old_tree = old_tree
 
904
        self.new_tree = new_tree
 
905
        self.to_file = to_file
 
906
        self.path_encoding = path_encoding
 
907
        self.differs = []
 
908
        if extra_factories is not None:
 
909
            self.differs.extend(f(self) for f in extra_factories)
 
910
        self.differs.extend(f(self) for f in self.diff_factories)
 
911
        self.differs.extend([diff_text, DiffKindChange.from_diff_tree(self)])
 
912
 
 
913
    @classmethod
 
914
    def from_trees_options(klass, old_tree, new_tree, to_file,
 
915
                           path_encoding, external_diff_options, old_label,
 
916
                           new_label, using, context_lines):
 
917
        """Factory for producing a DiffTree.
 
918
 
 
919
        Designed to accept options used by show_diff_trees.
 
920
 
 
921
        :param old_tree: The tree to show as old in the comparison
 
922
        :param new_tree: The tree to show as new in the comparison
 
923
        :param to_file: File to write comparisons to
 
924
        :param path_encoding: Character encoding to use for writing paths
 
925
        :param external_diff_options: If supplied, use the installed diff
 
926
            binary to perform file comparison, using supplied options.
 
927
        :param old_label: Prefix to use for old file labels
 
928
        :param new_label: Prefix to use for new file labels
 
929
        :param using: Commandline to use to invoke an external diff tool
 
930
        """
 
931
        if using is not None:
 
932
            extra_factories = [DiffFromTool.make_from_diff_tree(using, external_diff_options)]
 
933
        else:
 
934
            extra_factories = []
 
935
        if external_diff_options:
 
936
            opts = external_diff_options.split()
 
937
            def diff_file(olab, olines, nlab, nlines, to_file, path_encoding=None, context_lines=None):
 
938
                """:param path_encoding: not used but required
 
939
                        to match the signature of internal_diff.
 
940
                """
 
941
                external_diff(olab, olines, nlab, nlines, to_file, opts)
 
942
        else:
 
943
            diff_file = internal_diff
 
944
        diff_text = DiffText(old_tree, new_tree, to_file, path_encoding,
 
945
                             old_label, new_label, diff_file, context_lines=context_lines)
 
946
        return klass(old_tree, new_tree, to_file, path_encoding, diff_text,
 
947
                     extra_factories)
 
948
 
 
949
    def show_diff(self, specific_files, extra_trees=None):
 
950
        """Write tree diff to self.to_file
 
951
 
 
952
        :param specific_files: the specific files to compare (recursive)
 
953
        :param extra_trees: extra trees to use for mapping paths to file_ids
 
954
        """
 
955
        try:
 
956
            return self._show_diff(specific_files, extra_trees)
 
957
        finally:
 
958
            for differ in self.differs:
 
959
                differ.finish()
 
960
 
 
961
    def _show_diff(self, specific_files, extra_trees):
 
962
        # TODO: Generation of pseudo-diffs for added/deleted files could
 
963
        # be usefully made into a much faster special case.
 
964
        iterator = self.new_tree.iter_changes(self.old_tree,
 
965
                                               specific_files=specific_files,
 
966
                                               extra_trees=extra_trees,
 
967
                                               require_versioned=True)
 
968
        has_changes = 0
 
969
        def changes_key(change):
 
970
            old_path, new_path = change[1]
 
971
            path = new_path
 
972
            if path is None:
 
973
                path = old_path
 
974
            return path
 
975
        def get_encoded_path(path):
 
976
            if path is not None:
 
977
                return path.encode(self.path_encoding, "replace")
 
978
        for (file_id, paths, changed_content, versioned, parent, name, kind,
 
979
             executable) in sorted(iterator, key=changes_key):
 
980
            # The root does not get diffed, and items with no known kind (that
 
981
            # is, missing) in both trees are skipped as well.
 
982
            if parent == (None, None) or kind == (None, None):
 
983
                continue
 
984
            oldpath, newpath = paths
 
985
            oldpath_encoded = get_encoded_path(paths[0])
 
986
            newpath_encoded = get_encoded_path(paths[1])
 
987
            old_present = (kind[0] is not None and versioned[0])
 
988
            new_present = (kind[1] is not None and versioned[1])
 
989
            renamed = (parent[0], name[0]) != (parent[1], name[1])
 
990
 
 
991
            properties_changed = []
 
992
            properties_changed.extend(get_executable_change(executable[0], executable[1]))
 
993
 
 
994
            if properties_changed:
 
995
                prop_str = " (properties changed: %s)" % (", ".join(properties_changed),)
 
996
            else:
 
997
                prop_str = ""
 
998
 
 
999
            if (old_present, new_present) == (True, False):
 
1000
                self.to_file.write("=== removed %s '%s'\n" %
 
1001
                                   (kind[0], oldpath_encoded))
 
1002
                newpath = oldpath
 
1003
            elif (old_present, new_present) == (False, True):
 
1004
                self.to_file.write("=== added %s '%s'\n" %
 
1005
                                   (kind[1], newpath_encoded))
 
1006
                oldpath = newpath
 
1007
            elif renamed:
 
1008
                self.to_file.write("=== renamed %s '%s' => '%s'%s\n" %
 
1009
                    (kind[0], oldpath_encoded, newpath_encoded, prop_str))
 
1010
            else:
 
1011
                # if it was produced by iter_changes, it must be
 
1012
                # modified *somehow*, either content or execute bit.
 
1013
                self.to_file.write("=== modified %s '%s'%s\n" % (kind[0],
 
1014
                                   newpath_encoded, prop_str))
 
1015
            if changed_content:
 
1016
                self._diff(file_id, oldpath, newpath, kind[0], kind[1])
 
1017
                has_changes = 1
 
1018
            if renamed:
 
1019
                has_changes = 1
 
1020
        return has_changes
 
1021
 
 
1022
    def diff(self, file_id, old_path, new_path):
 
1023
        """Perform a diff of a single file
 
1024
 
 
1025
        :param file_id: file-id of the file
 
1026
        :param old_path: The path of the file in the old tree
 
1027
        :param new_path: The path of the file in the new tree
 
1028
        """
 
1029
        try:
 
1030
            old_kind = self.old_tree.kind(file_id)
 
1031
        except (errors.NoSuchId, errors.NoSuchFile):
 
1032
            old_kind = None
 
1033
        try:
 
1034
            new_kind = self.new_tree.kind(file_id)
 
1035
        except (errors.NoSuchId, errors.NoSuchFile):
 
1036
            new_kind = None
 
1037
        self._diff(file_id, old_path, new_path, old_kind, new_kind)
 
1038
 
 
1039
 
 
1040
    def _diff(self, file_id, old_path, new_path, old_kind, new_kind):
 
1041
        result = DiffPath._diff_many(self.differs, file_id, old_path,
 
1042
                                       new_path, old_kind, new_kind)
 
1043
        if result is DiffPath.CANNOT_DIFF:
 
1044
            error_path = new_path
 
1045
            if error_path is None:
 
1046
                error_path = old_path
 
1047
            raise errors.NoDiffFound(error_path)
 
1048
 
 
1049
 
 
1050
format_registry = Registry()
 
1051
format_registry.register('default', DiffTree)