Exclude codereview.settings from Crashpad

third_party/crashpad/update.py

 #!/usr/bin/env python
 # coding: utf-8
 
 # Copyright 2015 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import argparse
 import os
 import re
@@ skipping 50 matching lines @@
     parser.add_argument(
         '--fetch-ref',
         default='HEAD',
         help='The remote ref to fetch',
         metavar='REF')
     parser.add_argument(
         '--readme',
         help='The README.chromium file describing the imported project',
         metavar='FILE',
         dest='readme_path')
+    parser.add_argument(
+        '--exclude',
+        default=['codereview.settings'],
+        action='append',
+        help='Files to exclude from the imported copy',
+        metavar='PATH')
     parsed = parser.parse_args(args)
 
     original_head = (
         subprocess.check_output(['git', 'rev-parse', 'HEAD'],
                                 shell=IS_WINDOWS).rstrip())
 
     # Read the README, because that’s what it’s for. Extract some things from
     # it, and save it to be able to update it later.
     readme_path = (parsed.readme_path or
                    os.path.join(os.path.dirname(__file__ or '.'),
@@ skipping 19 matching lines @@
     # the update operation.
     if not GitMergeBaseIsAncestor(parsed.update_to, 'FETCH_HEAD'):
         raise Exception('update_to is not an ancestor of FETCH_HEAD',
                         parsed.update_to,
                         'FETCH_HEAD')
     if not GitMergeBaseIsAncestor(revision_old, parsed.update_to):
         raise Exception('revision_old is not an ancestor of update_to',
                         revision_old,
                         parsed.update_to)
 
-    update_range = revision_old + '..' + parsed.update_to
+    # git-filter-branch needs a ref to update. It’s not enough to just tell it
+    # to operate on a range of commits ending at parsed.update_to, because
+    # parsed.update_to is a commit hash that can’t be updated.
+    subprocess.check_call(['git', 'update-ref', 'UPDATE_TO', parsed.update_to],
+                          shell=IS_WINDOWS)
 
-    # This cherry-picks each change in the window from the upstream project into
-    # the current branch.
+    # Filter the range being updated over to exclude files that ought to be
+    # missing. This points UPDATE_TO to the rewritten (filtered) version.
+    # git-filter-branch inists on running from the top level of the working
+    # tree.
+    toplevel = subprocess.check_output(['git', 'rev-parse', '--show-toplevel'],
+                                       shell=IS_WINDOWS).rstrip()
+    subprocess.check_call(
+        ['git',
+         'filter-branch',
+         '--force',
+         '--index-filter',
+         'git rm --cached --ignore-unmatch ' + ' '.join(parsed.exclude),

[Mark Mentovai, 2017/03/02 02:38:05]

This line bothers me. How does git-filter-branch interpret it? Does it feed it
to the shell? Is there some quoting that should be applied?

+         revision_old + '..UPDATE_TO'],
+        cwd=toplevel,
+        shell=IS_WINDOWS)

[Mark Mentovai, 2017/03/02 02:38:05]

I’m concerned that the approach might not work on Windows at all, either because
of this line or…just because. I don’t remember why we always use shell=True on
Windows. Maybe Scott does.

[Mark Mentovai, 2017/03/02 02:40:46]

I wrote:
History remembers why: https://codereview.chromium.org/1561213002.

[scottmg, 2017/03/02 03:13:24]

Yeah, it's because depot_tools wraps git.exe in git.bat, which won't be found
unless the shell's used to find it.

I'm not sure how that command is run, but I think other git-commands that
themselves run git are run inside a git-bash, so it might be fine on Windows.

+
+    # git-filter-branch saved a copy of the original UPDATE_TO at
+    # original/UPDATE_TO, but this isn’t useful because it refers to the same
+    # thing as parsed.update_to, which is already known.
+    subprocess.check_call(
+        ['git', 'update-ref', '-d', 'refs/original/UPDATE_TO'],
+        shell=IS_WINDOWS)
+
+    filtered_update_range = revision_old + '..UPDATE_TO'
+    unfiltered_update_range = revision_old + '..' + parsed.update_to
+
+    # This cherry-picks each change in the window from the filtered view of the
+    # upstream project into the current branch.
     assisted_cherry_pick = False
     try:
         if not SubprocessCheckCall0Or1(['git',
                                         'cherry-pick',
                                         '--keep-redundant-commits',
                                         '--strategy=subtree',
                                         '-Xsubtree=' + parsed.subtree,
                                         '-x',
-                                        update_range]):
+                                        filtered_update_range]):
             assisted_cherry_pick = True
             print >>sys.stderr, ("""
 Please fix the errors above and run "git cherry-pick --continue".
 Press Enter when "git cherry-pick" completes.
 You may use a new shell for this, or ^Z if job control is available.
 Press ^C to abort.
 """)
             raw_input()
     except:
         # ^C, signal, or something else.
         print >>sys.stderr, 'Aborting...'
         subprocess.call(['git', 'cherry-pick', '--abort'], shell=IS_WINDOWS)
         raise
 
     # Get an abbreviated hash and subject line for each commit in the window,
-    # sorted in chronological order.
+    # sorted in chronological order. Use the unfiltered view so that the commit
+    # hashes are recognizable.
     log_lines = subprocess.check_output(['git',
                                          '-c',
                                          'core.abbrev=12',
                                          'log',
                                          '--abbrev-commit',
                                          '--pretty=oneline',
                                          '--reverse',
-                                         update_range],
+                                         unfiltered_update_range],
                                          shell=IS_WINDOWS).splitlines(False)
 
     if assisted_cherry_pick:
         # If the user had to help, count the number of cherry-picked commits,
         # expecting it to match.
         cherry_picked_commits = int(subprocess.check_output(
-            ['git', 'rev-list', '--count', original_head + '..HEAD']))
+            ['git', 'rev-list', '--count', original_head + '..HEAD'],
+            shell=IS_WINDOWS))
         if cherry_picked_commits != len(log_lines):
             print >>sys.stderr, 'Something smells fishy, aborting anyway...'
             subprocess.call(['git', 'cherry-pick', '--abort'], shell=IS_WINDOWS)
             raise Exception('not all commits were cherry-picked',
                             len(log_lines),
                             cherry_picked_commits)
 
     # Make a nice commit message. Start with the full commit hash.
     revision_new = subprocess.check_output(
         ['git', 'rev-parse', parsed.update_to], shell=IS_WINDOWS).rstrip()
@@ skipping 21 matching lines @@
         readme_content_old,
         1,
         re.MULTILINE)
 
     # If the in-tree copy has no changes relative to the upstream, clear the
     # “Local Modifications” section of the README.
     has_local_modifications = True
     if SubprocessCheckCall0Or1(['git',
                                 'diff-tree',
                                 '--quiet',
-                                parsed.update_to,
+                                'UPDATE_TO',
                                 'HEAD:' + parsed.subtree]):
         has_local_modifications = False
 
+        if not parsed.exclude:
+            modifications = 'None.\n'
+        elif len(parsed.exclude) == 1:
+            modifications = \
+                ' - %s has been excluded.\n' % parsed.exclude[0]
+        else:
+            modifications =\
+                ' - The following files have been excluded:\n'
+            for excluded in sorted(parsed.exclude):
+                modifications += '    - ' + excluded + '\n'
         readme_content_new = re.sub(r'\nLocal Modifications:\n.*$',
-                                    '\nLocal Modifications:\nNone.',
+                                    '\nLocal Modifications:\n' + modifications,
                                     readme_content_new,
-                                    1)
+                                    1,
+                                    re.DOTALL)
 
-    # This soft-reset causes all of the cherry-picks to show up as staged,
-    # which will have the effect of squashing them along with the README update
-    # when committed below.
+    # The UPDATE_TO ref is no longer useful.
+    subprocess.check_call(['git', 'update-ref', '-d', 'UPDATE_TO'],
+                          shell=IS_WINDOWS)
+
+    # This soft-reset causes all of the cherry-picks to show up as staged, which
+    # will have the effect of squashing them along with the README update when
+    # committed below.
     subprocess.check_call(['git', 'reset', '--soft', original_head],
                           shell=IS_WINDOWS)
 
     # Write the new README.
     open(readme_path, 'wb').write(readme_content_new)
 
     # Commit everything.
     subprocess.check_call(['git', 'add', readme_path], shell=IS_WINDOWS)
 
     try:
@@ skipping 11 matching lines @@
     if has_local_modifications:
         print >>sys.stderr, (
             'Remember to check the Local Modifications section in ' +
             readme_path)
 
     return 0
 
 
 if __name__ == '__main__':
     sys.exit(main(sys.argv[1:]))