Added common git 'checkout' function

gclient_scm.py

 # Copyright (c) 2012 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.
 
 """Gclient-specific SCM-specific operations."""
 
 from __future__ import print_function
 
 import errno
 import logging
@@ skipping 377 matching lines @@
       if mirror:
         self._UpdateMirror(mirror, options)
       try:
         self._Clone(revision, url, options)
       except subprocess2.CalledProcessError:
         self._DeleteOrMove(options.force)
         self._Clone(revision, url, options)
       if deps_revision and deps_revision.startswith('branch-heads/'):
         deps_branch = deps_revision.replace('branch-heads/', '')
         self._Capture(['branch', deps_branch, deps_revision])
-        self._Capture(['checkout', '--quiet', deps_branch])
+        self._Checkout(options, deps_branch, quiet=True)
       if file_list is not None:
         files = self._Capture(['ls-files']).splitlines()
         file_list.extend([os.path.join(self.checkout_path, f) for f in files])
       if not verbose:
         # Make the output a little prettier. It's nice to have some whitespace
         # between projects when cloning.
         self.Print('')
       return self._Capture(['rev-parse', '--verify', 'HEAD'])
 
     if not managed:
@@ skipping 84 matching lines @@
 
     if current_type == 'detached':
       # case 0
       self._CheckClean(rev_str)
       self._CheckDetachedHead(rev_str, options)
       if self._Capture(['rev-list', '-n', '1', 'HEAD']) == revision:
         self.Print('Up-to-date; skipping checkout.')
       else:
         # 'git checkout' may need to overwrite existing untracked files. Allow
         # it only when nuclear options are enabled.
-        if options.force and options.delete_unversioned_trees:
-          self._Capture(['checkout', '--force', '--quiet', '%s' % revision])
-        else:
-          self._Capture(['checkout', '--quiet', '%s' % revision])
+        self._Checkout(
+            options,
+            revision,
+            force=(options.force and options.delete_unversioned_trees),
+            quiet=True,
+        )
       if not printed_path:
         self.Print('_____ %s%s' % (self.relpath, rev_str), timestamp=False)
     elif current_type == 'hash':
       # case 1
       if scm.GIT.IsGitSvn(self.checkout_path) and upstream_branch is not None:
         # Our git-svn branch (upstream_branch) is our upstream
         self._AttemptRebase(upstream_branch, files, options,
                             newbase=revision, printed_path=printed_path,
                             merge=options.merge)
         printed_path = True
@@ skipping 318 matching lines @@
       gclient_utils.safe_rename(os.path.join(tmp_dir, '.git'),
                                 os.path.join(self.checkout_path, '.git'))
     except:
       traceback.print_exc(file=self.out_fh)
       raise
     finally:
       if os.listdir(tmp_dir):
         self.Print('_____ removing non-empty tmp dir %s' % tmp_dir)
       gclient_utils.rmtree(tmp_dir)
     self._UpdateBranchHeads(options, fetch=True)
-    self._Run(['checkout', '--quiet', revision.replace('refs/heads/', '')],
-              options)
+    self._Checkout(options, revision.replace('refs/heads/', ''), quiet=True)
     if self._GetCurrentBranch() is None:
       # Squelch git's very verbose detached HEAD warning and use our own
       self.Print(
         ('Checked out %s to a detached HEAD. Before making any commits\n'
          'in this repo, you should use \'git checkout <branch>\' to switch to\n'
          'an existing branch or use \'git checkout %s -b <branch>\' to\n'
          'create a new branch for your work.') % (revision, self.remote))
 
   def _AskForData(self, prompt, options):
     if options.jobs > 1:
@@ skipping 152 matching lines @@
     if branch == 'HEAD':
       return None
     return branch
 
   def _Capture(self, args, **kwargs):
     kwargs.setdefault('cwd', self.checkout_path)
     kwargs.setdefault('stderr', subprocess2.PIPE)
     env = scm.GIT.ApplyEnvVars(kwargs)
     return subprocess2.check_output(['git'] + args, env=env, **kwargs).strip()
 
+  def _Checkout(self, options, ref, force=False, quiet=None):
+    """Performs a 'git-checkout' operation.
+
+    Args:
+      options: The configured option set
+      ref: (str) The branch/commit to checkout
+      quiet: (bool/None) Whether or not the checkout shoud pass '--quiet'; if
+          'None', the behavior is inferred from 'options.verbose'.
+    Returns: (str) The output of the checkout operation
+    """
+    if quiet is None:
+      quiet = (not options.verbose)
+    checkout_args = ['checkout']
+    if force:
+      checkout_args.append('--force')
+    if quiet:
+      checkout_args.append('--quiet')
+    checkout_args.append(ref)
+    return self._Capture(checkout_args)
+
   def _UpdateBranchHeads(self, options, fetch=False):
     """Adds, and optionally fetches, "branch-heads" refspecs if requested."""
     if hasattr(options, 'with_branch_heads') and options.with_branch_heads:
       config_cmd = ['config', 'remote.%s.fetch' % self.remote,
                     '+refs/branch-heads/*:refs/remotes/branch-heads/*',
                     '^\\+refs/branch-heads/\\*:.*$']
       self._Run(config_cmd, options)
       if fetch:
         cfg = gclient_utils.DefaultIndexPackConfig(self.url)
         fetch_cmd =  cfg + ['fetch', self.remote]
@@ skipping 475 matching lines @@
       new_command.append('--force')
       if command[0] != 'checkout' and scm.SVN.AssertVersion('1.6')[0]:
         new_command.extend(('--accept', 'theirs-conflict'))
     elif options.manually_grab_svn_rev:
       new_command.append('--force')
       if command[0] != 'checkout' and scm.SVN.AssertVersion('1.6')[0]:
         new_command.extend(('--accept', 'postpone'))
     elif command[0] != 'checkout' and scm.SVN.AssertVersion('1.6')[0]:
       new_command.extend(('--accept', 'postpone'))
     return new_command