Perform Git operations without changing CWD.

recipe_engine/package.py

 # 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 ast
 import collections
 import contextlib
 import copy
 import functools
 import itertools
@@ skipping 178 matching lines @@
     self.repo = repo
     self.branch = branch
     self.revision = revision
     self.path = path
 
   def __str__(self):
     return ('GitRepoSpec{project_id="%(project_id)s", repo="%(repo)s", '
             'branch="%(branch)s", revision="%(revision)s", '
             'path="%(path)s"}' % self.__dict__)
 
+  def run_git(self, cwd, *args):
+    _run_cmd([self._git, '--git-dir', os.path.join(cwd, '.git')] + list(args))
+
   def checkout(self, context):
     dep_dir = self._dep_dir(context)
     logging.info('Freshening repository %s' % dep_dir)
 
     if not os.path.isdir(dep_dir):
       _run_cmd([self._git, 'clone', self.repo, dep_dir])
     elif not os.path.isdir(os.path.join(dep_dir, '.git')):
       raise UncleanFilesystemError('%s exists but is not a git repo' % dep_dir)
 
     try:
-      subprocess.check_output([self._git, 'rev-parse', '-q', '--verify',
-                               '%s^{commit}' % self.revision], cwd=dep_dir)
+      self.run_git(dep_dir, 'rev-parse', '-q', '--verify',
+                    '%s^{commit}' % self.revision)
     except subprocess.CalledProcessError:
-      _run_cmd([self._git, 'fetch'], cwd=dep_dir)
-    _run_cmd([self._git, 'reset', '-q', '--hard', self.revision], cwd=dep_dir)
+      self.run_git(dep_dir, 'fetch')
+    self.run_git(dep_dir, 'reset', '-q', '--hard', self.revision)
 
   def check_checkout(self, context):
     dep_dir = self._dep_dir(context)
     if not os.path.isdir(dep_dir):
       raise UncleanFilesystemError('Dependency %s does not exist' %
                                    dep_dir)
     elif not os.path.isdir(os.path.join(dep_dir, '.git')):
       raise UncleanFilesystemError('Dependency %s is not a git repo' %
                                    dep_dir)
 
@@ skipping 28 matching lines @@
     for rev in lines:
       info = self._get_commit_info(rev, context)
       updates.append(RepoUpdate(
                  GitRepoSpec(self.project_id, self.repo, self.branch, rev,
                              self.path),
                  commit_infos=(info,)))
     return updates
 
   def _raw_updates(self, context, subdir):
     self.checkout(context)
-    _run_cmd([self._git, 'fetch'], cwd=self._dep_dir(context))
+    self.run_git(self._dep_dir(context), fetch)

[Paweł Hajdan Jr., 2016/03/31 17:35:37]

Shouldn't fetch be changed to 'fetch'? Just checking.

[dnj, 2016/03/31 17:47:50]

Done.

     args = [self._git, 'rev-list', '--reverse',
             '%s..origin/%s' % (self.revision, self.branch)]
     if subdir:
       # We add proto_file to the list of paths to check because it might contain
       # other upstream rolls, which we want.
       args.extend(['--', subdir + os.path.sep, self.proto_file(context).path])
     git = subprocess.Popen(
         args, stdout=subprocess.PIPE, cwd=self._dep_dir(context))
     (stdout, _) = git.communicate()
     return stdout
@@ skipping 458 matching lines @@
   >>> d = { 'x': 1, 'y': 2 }
   >>> sorted(_updated(d, { 'y': 3, 'z': 4 }).items())
   [('x', 1), ('y', 3), ('z', 4)]
   >>> sorted(d.items())
   [('x', 1), ('y', 2)]
   """
 
   d = copy.copy(d)
   d.update(updates)
   return d