drover win: Use --stdin so update-index doesn't fail on long cmdline

git_drover.py

 #!/usr/bin/env python
 # 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.
 """git drover: A tool for merging changes to release branches."""
 
 import argparse
 import cPickle
 import functools
 import logging
@@ skipping 247 matching lines @@
       cPickle.dump(self, f)
 
   def _prepare_manual_resolve(self):
     """Prepare the workdir for the user to manually resolve the cherry-pick."""
     # Files that have been deleted between branch and cherry-pick will not have
     # their skip-worktree bit set so set it manually for those files to avoid
     # git status incorrectly listing them as unstaged deletes.
     repo_status = self._run_git_command(['status', '--porcelain']).splitlines()
     extra_files = [f[3:] for f in repo_status if f[:2] == ' D']
     if extra_files:
-      self._run_git_command(['update-index', '--skip-worktree', '--'] +
-                            extra_files)
+      self._run_git_command_with_stdin(
+          ['update-index', '--skip-worktree', '--stdin'],
+          stdin='\n'.join(extra_files) + '\n')
 
   def _upload_and_land(self):
     if self._dry_run:
       logging.info('--dry_run enabled; not landing.')
       return True
 
     self._run_git_command(['reset', '--hard'])
     self._run_git_command(['cl', 'upload'],
                           error_message='Upload failed',
                           interactive=True)
@@ skipping 27 matching lines @@
     stderr = None if self._verbose else _DEV_NULL_FILE
 
     try:
       return run(['git'] + args, shell=False, cwd=cwd, stderr=stderr)
     except (OSError, subprocess.CalledProcessError) as e:
       if error_message:
         raise Error(error_message)
       else:
         raise Error('Command %r failed: %s' % (' '.join(args), e))
 
+  def _run_git_command_with_stdin(self, args, stdin):
+    """Runs a git command with a provided stdin.
+
+    Args:
+      args: A list of strings containing the args to pass to git.
+      stdin: A string to provide on stdin.
+
+    Raises:
+      Error: The command failed to complete successfully.
+    """
+    cwd = self._workdir if self._workdir else self._parent_repo
+    logging.debug('Running git %s (cwd %r)', ' '.join('%s' % arg
+                                                      for arg in args), cwd)
+
+    # Discard stderr unless verbose is enabled.
+    stderr = None if self._verbose else _DEV_NULL_FILE
+
+    try:
+      popen = subprocess.Popen(['git'] + args, shell=False, cwd=cwd,
+                               stderr=stderr, stdin=subprocess.PIPE)
+      popen.communicate(stdin)
+      if popen.returncode != 0:
+        raise Error('Command %r failed' % ' '.join(args))
+    except OSError as e:
+      raise Error('Command %r failed: %s' % (' '.join(args), e))
+
 
 def cherry_pick_change(branch, revision, parent_repo, dry_run, verbose=False):
   """Cherry-picks a change into a branch.
 
   Args:
     branch: A string containing the release branch number to which to
         cherry-pick.
     revision: A string containing the revision to cherry-pick. It can be any
         string that git-rev-parse can identify as referring to a single
         revision.
@@ skipping 88 matching lines @@
       cherry_pick_change(options.branch, options.cherry_pick,
                          options.parent_checkout, options.dry_run,
                          options.verbose)
   except Error as e:
     print 'Error:', e.message
     sys.exit(128)
 
 
 if __name__ == '__main__':
   main()