Move git-cl into depot_tools....

git_cl/upload.py

Index: git_cl/upload.py
===================================================================
--- git_cl/upload.py	(revision 0)
+++ git_cl/upload.py	(revision 0)
@@ -0,0 +1,1774 @@
+#!/usr/bin/env python
+#
+# Copyright 2007 Google Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Tool for uploading diffs from a version control system to the codereview app.
+
+Usage summary: upload.py [options] [-- diff_options]
+
+Diff options are passed to the diff command of the underlying system.
+
+Supported version control systems:
+  Git
+  Mercurial
+  Subversion
+
+It is important for Git/Mercurial users to specify a tree/node/branch to diff
+against by using the '--rev' option.
+"""
+# This code is derived from appcfg.py in the App Engine SDK (open source),
+# and from ASPN recipe #146306.
+
+import ConfigParser
+import cookielib
+import fnmatch
+import getpass
+import logging
+import mimetypes
+import optparse
+import os
+import re
+import socket
+import subprocess
+import sys
+import urllib
+import urllib2
+import urlparse
+
+# The md5 module was deprecated in Python 2.5.
+try:
+  from hashlib import md5
+except ImportError:
+  from md5 import md5
+
+try:
+  import readline
+except ImportError:
+  pass
+
+try:
+  import keyring
+except ImportError:
+  keyring = None
+
+# The logging verbosity:
+#  0: Errors only.
+#  1: Status messages.
+#  2: Info logs.
+#  3: Debug logs.
+verbosity = 1
+
+# The account type used for authentication.
+# This line could be changed by the review server (see handler for
+# upload.py).
+AUTH_ACCOUNT_TYPE = "GOOGLE"
+
+# URL of the default review server. As for AUTH_ACCOUNT_TYPE, this line could be
+# changed by the review server (see handler for upload.py).
+DEFAULT_REVIEW_SERVER = "codereview.appspot.com"
+
+# Max size of patch or base file.
+MAX_UPLOAD_SIZE = 900 * 1024
+
+# Constants for version control names.  Used by GuessVCSName.
+VCS_GIT = "Git"
+VCS_MERCURIAL = "Mercurial"
+VCS_SUBVERSION = "Subversion"
+VCS_UNKNOWN = "Unknown"
+
+# whitelist for non-binary filetypes which do not start with "text/"
+# .mm (Objective-C) shows up as application/x-freemind on my Linux box.
+TEXT_MIMETYPES = ['application/javascript', 'application/x-javascript',
+                  'application/xml', 'application/x-freemind', 
+                  'application/x-sh']
+
+VCS_ABBREVIATIONS = {
+  VCS_MERCURIAL.lower(): VCS_MERCURIAL,
+  "hg": VCS_MERCURIAL,
+  VCS_SUBVERSION.lower(): VCS_SUBVERSION,
+  "svn": VCS_SUBVERSION,
+  VCS_GIT.lower(): VCS_GIT,
+}
+
+# The result of parsing Subversion's [auto-props] setting.
+svn_auto_props_map = None
+
+def GetEmail(prompt):
+  """Prompts the user for their email address and returns it.
+
+  The last used email address is saved to a file and offered up as a suggestion
+  to the user. If the user presses enter without typing in anything the last
+  used email address is used. If the user enters a new address, it is saved
+  for next time we prompt.
+
+  """
+  last_email_file_name = os.path.expanduser("~/.last_codereview_email_address")
+  last_email = ""
+  if os.path.exists(last_email_file_name):
+    try:
+      last_email_file = open(last_email_file_name, "r")
+      last_email = last_email_file.readline().strip("\n")
+      last_email_file.close()
+      prompt += " [%s]" % last_email
+    except IOError, e:
+      pass
+  email = raw_input(prompt + ": ").strip()
+  if email:
+    try:
+      last_email_file = open(last_email_file_name, "w")
+      last_email_file.write(email)
+      last_email_file.close()
+    except IOError, e:
+      pass
+  else:
+    email = last_email
+  return email
+
+
+def StatusUpdate(msg):
+  """Print a status message to stdout.
+
+  If 'verbosity' is greater than 0, print the message.
+
+  Args:
+    msg: The string to print.
+  """
+  if verbosity > 0:
+    print msg
+
+
+def ErrorExit(msg):
+  """Print an error message to stderr and exit."""
+  print >>sys.stderr, msg
+  sys.exit(1)
+
+
+class ClientLoginError(urllib2.HTTPError):
+  """Raised to indicate there was an error authenticating with ClientLogin."""
+
+  def __init__(self, url, code, msg, headers, args):
+    urllib2.HTTPError.__init__(self, url, code, msg, headers, None)
+    self.args = args
+    self.reason = args["Error"]
+
+
+class AbstractRpcServer(object):
+  """Provides a common interface for a simple RPC server."""
+
+  def __init__(self, host, auth_function, host_override=None, extra_headers={},
+               save_cookies=False, account_type=AUTH_ACCOUNT_TYPE):
+    """Creates a new HttpRpcServer.
+
+    Args:
+      host: The host to send requests to.
+      auth_function: A function that takes no arguments and returns an
+        (email, password) tuple when called. Will be called if authentication
+        is required.
+      host_override: The host header to send to the server (defaults to host).
+      extra_headers: A dict of extra headers to append to every request.
+      save_cookies: If True, save the authentication cookies to local disk.
+        If False, use an in-memory cookiejar instead.  Subclasses must
+        implement this functionality.  Defaults to False.
+      account_type: Account type used for authentication. Defaults to
+        AUTH_ACCOUNT_TYPE.
+    """
+    self.host = host
+    if (not self.host.startswith("http://") and
+        not self.host.startswith("https://")):
+      self.host = "http://" + self.host
+    self.host_override = host_override
+    self.auth_function = auth_function
+    self.authenticated = False
+    self.extra_headers = extra_headers
+    self.save_cookies = save_cookies
+    self.account_type = account_type
+    self.opener = self._GetOpener()
+    if self.host_override:
+      logging.info("Server: %s; Host: %s", self.host, self.host_override)
+    else:
+      logging.info("Server: %s", self.host)
+
+  def _GetOpener(self):
+    """Returns an OpenerDirector for making HTTP requests.
+
+    Returns:
+      A urllib2.OpenerDirector object.
+    """
+    raise NotImplementedError()
+
+  def _CreateRequest(self, url, data=None):
+    """Creates a new urllib request."""
+    logging.debug("Creating request for: '%s' with payload:\n%s", url, data)
+    req = urllib2.Request(url, data=data)
+    if self.host_override:
+      req.add_header("Host", self.host_override)
+    for key, value in self.extra_headers.iteritems():
+      req.add_header(key, value)
+    return req
+
+  def _GetAuthToken(self, email, password):
+    """Uses ClientLogin to authenticate the user, returning an auth token.
+
+    Args:
+      email:    The user's email address
+      password: The user's password
+
+    Raises:
+      ClientLoginError: If there was an error authenticating with ClientLogin.
+      HTTPError: If there was some other form of HTTP error.
+
+    Returns:
+      The authentication token returned by ClientLogin.
+    """
+    account_type = self.account_type
+    if self.host.endswith(".google.com"):
+      # Needed for use inside Google.
+      account_type = "HOSTED"
+    req = self._CreateRequest(
+        url="https://www.google.com/accounts/ClientLogin",
+        data=urllib.urlencode({
+            "Email": email,
+            "Passwd": password,
+            "service": "ah",
+            "source": "rietveld-codereview-upload",
+            "accountType": account_type,
+        }),
+    )
+    try:
+      response = self.opener.open(req)
+      response_body = response.read()
+      response_dict = dict(x.split("=")
+                           for x in response_body.split("\n") if x)
+      return response_dict["Auth"]
+    except urllib2.HTTPError, e:
+      if e.code == 403:
+        body = e.read()
+        response_dict = dict(x.split("=", 1) for x in body.split("\n") if x)
+        raise ClientLoginError(req.get_full_url(), e.code, e.msg,
+                               e.headers, response_dict)
+      else:
+        raise
+
+  def _GetAuthCookie(self, auth_token):
+    """Fetches authentication cookies for an authentication token.
+
+    Args:
+      auth_token: The authentication token returned by ClientLogin.
+
+    Raises:
+      HTTPError: If there was an error fetching the authentication cookies.
+    """
+    # This is a dummy value to allow us to identify when we're successful.
+    continue_location = "http://localhost/"
+    args = {"continue": continue_location, "auth": auth_token}
+    req = self._CreateRequest("%s/_ah/login?%s" %
+                              (self.host, urllib.urlencode(args)))
+    try:
+      response = self.opener.open(req)
+    except urllib2.HTTPError, e:
+      response = e
+    if (response.code != 302 or
+        response.info()["location"] != continue_location):
+      raise urllib2.HTTPError(req.get_full_url(), response.code, response.msg,
+                              response.headers, response.fp)
+    self.authenticated = True
+
+  def _Authenticate(self):
+    """Authenticates the user.
+
+    The authentication process works as follows:
+     1) We get a username and password from the user
+     2) We use ClientLogin to obtain an AUTH token for the user
+        (see http://code.google.com/apis/accounts/AuthForInstalledApps.html).
+     3) We pass the auth token to /_ah/login on the server to obtain an
+        authentication cookie. If login was successful, it tries to redirect
+        us to the URL we provided.
+
+    If we attempt to access the upload API without first obtaining an
+    authentication cookie, it returns a 401 response (or a 302) and
+    directs us to authenticate ourselves with ClientLogin.
+    """
+    for i in range(3):
+      credentials = self.auth_function()
+      try:
+        auth_token = self._GetAuthToken(credentials[0], credentials[1])
+      except ClientLoginError, e:
+        if e.reason == "BadAuthentication":
+          print >>sys.stderr, "Invalid username or password."
+          continue
+        if e.reason == "CaptchaRequired":
+          print >>sys.stderr, (
+              "Please go to\n"
+              "https://www.google.com/accounts/DisplayUnlockCaptcha\n"
+              "and verify you are a human.  Then try again.\n"
+              "If you are using a Google Apps account the URL is:\n"
+              "https://www.google.com/a/yourdomain.com/UnlockCaptcha")
+          break
+        if e.reason == "NotVerified":
+          print >>sys.stderr, "Account not verified."
+          break
+        if e.reason == "TermsNotAgreed":
+          print >>sys.stderr, "User has not agreed to TOS."
+          break
+        if e.reason == "AccountDeleted":
+          print >>sys.stderr, "The user account has been deleted."
+          break
+        if e.reason == "AccountDisabled":
+          print >>sys.stderr, "The user account has been disabled."
+          break
+        if e.reason == "ServiceDisabled":
+          print >>sys.stderr, ("The user's access to the service has been "
+                               "disabled.")
+          break
+        if e.reason == "ServiceUnavailable":
+          print >>sys.stderr, "The service is not available; try again later."
+          break
+        raise
+      self._GetAuthCookie(auth_token)
+      return
+
+  def Send(self, request_path, payload=None,
+           content_type="application/octet-stream",
+           timeout=None,
+           extra_headers=None,
+           **kwargs):
+    """Sends an RPC and returns the response.
+
+    Args:
+      request_path: The path to send the request to, eg /api/appversion/create.
+      payload: The body of the request, or None to send an empty request.
+      content_type: The Content-Type header to use.
+      timeout: timeout in seconds; default None i.e. no timeout.
+        (Note: for large requests on OS X, the timeout doesn't work right.)
+      extra_headers: Dict containing additional HTTP headers that should be
+        included in the request (string header names mapped to their values),
+        or None to not include any additional headers.
+      kwargs: Any keyword arguments are converted into query string parameters.
+
+    Returns:
+      The response body, as a string.
+    """
+    # TODO: Don't require authentication.  Let the server say
+    # whether it is necessary.
+    if not self.authenticated:
+      self._Authenticate()
+
+    old_timeout = socket.getdefaulttimeout()
+    socket.setdefaulttimeout(timeout)
+    try:
+      tries = 0
+      while True:
+        tries += 1
+        args = dict(kwargs)
+        url = "%s%s" % (self.host, request_path)
+        if args:
+          url += "?" + urllib.urlencode(args)
+        req = self._CreateRequest(url=url, data=payload)
+        req.add_header("Content-Type", content_type)
+        if extra_headers:
+          for header, value in extra_headers.items():
+            req.add_header(header, value)
+        try:
+          f = self.opener.open(req)
+          response = f.read()
+          f.close()
+          return response
+        except urllib2.HTTPError, e:
+          if tries > 3:
+            raise
+          elif e.code == 401 or e.code == 302:
+            self._Authenticate()
+##           elif e.code >= 500 and e.code < 600:
+##             # Server Error - try again.
+##             continue
+          else:
+            raise
+    finally:
+      socket.setdefaulttimeout(old_timeout)
+
+
+class HttpRpcServer(AbstractRpcServer):
+  """Provides a simplified RPC-style interface for HTTP requests."""
+
+  def _Authenticate(self):
+    """Save the cookie jar after authentication."""
+    super(HttpRpcServer, self)._Authenticate()
+    if self.save_cookies:
+      StatusUpdate("Saving authentication cookies to %s" % self.cookie_file)
+      self.cookie_jar.save()
+
+  def _GetOpener(self):
+    """Returns an OpenerDirector that supports cookies and ignores redirects.
+
+    Returns:
+      A urllib2.OpenerDirector object.
+    """
+    opener = urllib2.OpenerDirector()
+    opener.add_handler(urllib2.ProxyHandler())
+    opener.add_handler(urllib2.UnknownHandler())
+    opener.add_handler(urllib2.HTTPHandler())
+    opener.add_handler(urllib2.HTTPDefaultErrorHandler())
+    opener.add_handler(urllib2.HTTPSHandler())
+    opener.add_handler(urllib2.HTTPErrorProcessor())
+    if self.save_cookies:
+      self.cookie_file = os.path.expanduser("~/.codereview_upload_cookies")
+      self.cookie_jar = cookielib.MozillaCookieJar(self.cookie_file)
+      if os.path.exists(self.cookie_file):
+        try:
+          self.cookie_jar.load()
+          self.authenticated = True
+          StatusUpdate("Loaded authentication cookies from %s" %
+                       self.cookie_file)
+        except (cookielib.LoadError, IOError):
+          # Failed to load cookies - just ignore them.
+          pass
+      else:
+        # Create an empty cookie file with mode 600
+        fd = os.open(self.cookie_file, os.O_CREAT, 0600)
+        os.close(fd)
+      # Always chmod the cookie file
+      os.chmod(self.cookie_file, 0600)
+    else:
+      # Don't save cookies across runs of update.py.
+      self.cookie_jar = cookielib.CookieJar()
+    opener.add_handler(urllib2.HTTPCookieProcessor(self.cookie_jar))
+    return opener
+
+
+parser = optparse.OptionParser(usage="%prog [options] [-- diff_options]")
+parser.add_option("-y", "--assume_yes", action="store_true",
+                  dest="assume_yes", default=False,
+                  help="Assume that the answer to yes/no questions is 'yes'.")
+# Logging
+group = parser.add_option_group("Logging options")
+group.add_option("-q", "--quiet", action="store_const", const=0,
+                 dest="verbose", help="Print errors only.")
+group.add_option("-v", "--verbose", action="store_const", const=2,
+                 dest="verbose", default=1,
+                 help="Print info level logs (default).")
+group.add_option("--noisy", action="store_const", const=3,
+                 dest="verbose", help="Print all logs.")
+# Review server
+group = parser.add_option_group("Review server options")
+group.add_option("-s", "--server", action="store", dest="server",
+                 default=DEFAULT_REVIEW_SERVER,
+                 metavar="SERVER",
+                 help=("The server to upload to. The format is host[:port]. "
+                       "Defaults to '%default'."))
+group.add_option("-e", "--email", action="store", dest="email",
+                 metavar="EMAIL", default=None,
+                 help="The username to use. Will prompt if omitted.")
+group.add_option("-H", "--host", action="store", dest="host",
+                 metavar="HOST", default=None,
+                 help="Overrides the Host header sent with all RPCs.")
+group.add_option("--no_cookies", action="store_false",
+                 dest="save_cookies", default=True,
+                 help="Do not save authentication cookies to local disk.")
+group.add_option("--account_type", action="store", dest="account_type",
+                 metavar="TYPE", default=AUTH_ACCOUNT_TYPE,
+                 choices=["GOOGLE", "HOSTED"],
+                 help=("Override the default account type "
+                       "(defaults to '%default', "
+                       "valid choices are 'GOOGLE' and 'HOSTED')."))
+# Issue
+group = parser.add_option_group("Issue options")
+group.add_option("-d", "--description", action="store", dest="description",
+                 metavar="DESCRIPTION", default=None,
+                 help="Optional description when creating an issue.")
+group.add_option("-f", "--description_file", action="store",
+                 dest="description_file", metavar="DESCRIPTION_FILE",
+                 default=None,
+                 help="Optional path of a file that contains "
+                      "the description when creating an issue.")
+group.add_option("-r", "--reviewers", action="store", dest="reviewers",
+                 metavar="REVIEWERS", default=None,
+                 help="Add reviewers (comma separated email addresses).")
+group.add_option("--cc", action="store", dest="cc",
+                 metavar="CC", default=None,
+                 help="Add CC (comma separated email addresses).")
+group.add_option("--private", action="store_true", dest="private",
+                 default=False,
+                 help="Make the issue restricted to reviewers and those CCed")
+# Upload options
+group = parser.add_option_group("Patch options")
+group.add_option("-m", "--message", action="store", dest="message",
+                 metavar="MESSAGE", default=None,
+                 help="A message to identify the patch. "
+                      "Will prompt if omitted.")
+group.add_option("-i", "--issue", type="int", action="store",
+                 metavar="ISSUE", default=None,
+                 help="Issue number to which to add. Defaults to new issue.")
+group.add_option("--base_url", action="store", dest="base_url", default=None,
+                 help="Base repository URL (listed as \"Base URL\" when "
+                 "viewing issue).  If omitted, will be guessed automatically "
+                 "for SVN repos and left blank for others.")
+group.add_option("--download_base", action="store_true",
+                 dest="download_base", default=False,
+                 help="Base files will be downloaded by the server "
+                 "(side-by-side diffs may not work on files with CRs).")
+group.add_option("--rev", action="store", dest="revision",
+                 metavar="REV", default=None,
+                 help="Base revision/branch/tree to diff against. Use "
+                      "rev1:rev2 range to review already committed changeset.")
+group.add_option("--send_mail", action="store_true",
+                 dest="send_mail", default=False,
+                 help="Send notification email to reviewers.")
+group.add_option("--vcs", action="store", dest="vcs",
+                 metavar="VCS", default=None,
+                 help=("Version control system (optional, usually upload.py "
+                       "already guesses the right VCS)."))
+group.add_option("--emulate_svn_auto_props", action="store_true",
+                 dest="emulate_svn_auto_props", default=False,
+                 help=("Emulate Subversion's auto properties feature."))
+
+
+def GetRpcServer(server, email=None, host_override=None, save_cookies=True,
+                 account_type=AUTH_ACCOUNT_TYPE):
+  """Returns an instance of an AbstractRpcServer.
+
+  Args:
+    server: String containing the review server URL.
+    email: String containing user's email address.
+    host_override: If not None, string containing an alternate hostname to use
+      in the host header.
+    save_cookies: Whether authentication cookies should be saved to disk.
+    account_type: Account type for authentication, either 'GOOGLE'
+      or 'HOSTED'. Defaults to AUTH_ACCOUNT_TYPE.
+
+  Returns:
+    A new AbstractRpcServer, on which RPC calls can be made.
+  """
+
+  rpc_server_class = HttpRpcServer
+
+  # If this is the dev_appserver, use fake authentication.
+  host = (host_override or server).lower()
+  if re.match(r'(http://)?localhost([:/]|$)', host):
+    if email is None:
+      email = "test@example.com"
+      logging.info("Using debug user %s.  Override with --email" % email)
+    server = rpc_server_class(
+        server,
+        lambda: (email, "password"),
+        host_override=host_override,
+        extra_headers={"Cookie":
+                       'dev_appserver_login="%s:False"' % email},
+        save_cookies=save_cookies,
+        account_type=account_type)
+    # Don't try to talk to ClientLogin.
+    server.authenticated = True
+    return server
+
+  def GetUserCredentials():
+    """Prompts the user for a username and password."""
+    # Create a local alias to the email variable to avoid Python's crazy
+    # scoping rules.
+    local_email = email
+    if local_email is None:
+      local_email = GetEmail("Email (login for uploading to %s)" % server)
+    password = None
+    if keyring:
+      password = keyring.get_password(host, local_email)
+    if password is not None:
+      print "Using password from system keyring."
+    else:
+      password = getpass.getpass("Password for %s: " % local_email)
+      if keyring:
+        answer = raw_input("Store password in system keyring?(y/N) ").strip()
+        if answer == "y":
+          keyring.set_password(host, local_email, password)
+    return (local_email, password)
+
+  return rpc_server_class(server,
+                          GetUserCredentials,
+                          host_override=host_override,
+                          save_cookies=save_cookies)
+
+
+def EncodeMultipartFormData(fields, files):
+  """Encode form fields for multipart/form-data.
+
+  Args:
+    fields: A sequence of (name, value) elements for regular form fields.
+    files: A sequence of (name, filename, value) elements for data to be
+           uploaded as files.
+  Returns:
+    (content_type, body) ready for httplib.HTTP instance.
+
+  Source:
+    http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/146306
+  """
+  BOUNDARY = '-M-A-G-I-C---B-O-U-N-D-A-R-Y-'
+  CRLF = '\r\n'
+  lines = []
+  for (key, value) in fields:
+    lines.append('--' + BOUNDARY)
+    lines.append('Content-Disposition: form-data; name="%s"' % key)
+    lines.append('')
+    if isinstance(value, unicode):
+      value = value.encode('utf-8')
+    lines.append(value)
+  for (key, filename, value) in files:
+    lines.append('--' + BOUNDARY)
+    lines.append('Content-Disposition: form-data; name="%s"; filename="%s"' %
+             (key, filename))
+    lines.append('Content-Type: %s' % GetContentType(filename))
+    lines.append('')
+    if isinstance(value, unicode):
+      value = value.encode('utf-8')
+    lines.append(value)
+  lines.append('--' + BOUNDARY + '--')
+  lines.append('')
+  body = CRLF.join(lines)
+  content_type = 'multipart/form-data; boundary=%s' % BOUNDARY
+  return content_type, body
+
+
+def GetContentType(filename):
+  """Helper to guess the content-type from the filename."""
+  return mimetypes.guess_type(filename)[0] or 'application/octet-stream'
+
+
+# Use a shell for subcommands on Windows to get a PATH search.
+use_shell = sys.platform.startswith("win")
+
+def RunShellWithReturnCode(command, print_output=False,
+                           universal_newlines=True,
+                           env=os.environ):
+  """Executes a command and returns the output from stdout and the return code.
+
+  Args:
+    command: Command to execute.
+    print_output: If True, the output is printed to stdout.
+                  If False, both stdout and stderr are ignored.
+    universal_newlines: Use universal_newlines flag (default: True).
+
+  Returns:
+    Tuple (output, return code)
+  """
+  logging.info("Running %s", command)
+  p = subprocess.Popen(command, stdout=subprocess.PIPE, stderr=subprocess.PIPE,
+                       shell=use_shell, universal_newlines=universal_newlines,
+                       env=env)
+  if print_output:
+    output_array = []
+    while True:
+      line = p.stdout.readline()
+      if not line:
+        break
+      print line.strip("\n")
+      output_array.append(line)
+    output = "".join(output_array)
+  else:
+    output = p.stdout.read()
+  p.wait()
+  errout = p.stderr.read()
+  if print_output and errout:
+    print >>sys.stderr, errout
+  p.stdout.close()
+  p.stderr.close()
+  return output, p.returncode
+
+
+def RunShell(command, silent_ok=False, universal_newlines=True,
+             print_output=False, env=os.environ):
+  data, retcode = RunShellWithReturnCode(command, print_output,
+                                         universal_newlines, env)
+  if retcode:
+    ErrorExit("Got error status from %s:\n%s" % (command, data))
+  if not silent_ok and not data:
+    ErrorExit("No output from %s" % command)
+  return data
+
+
+class VersionControlSystem(object):
+  """Abstract base class providing an interface to the VCS."""
+
+  def __init__(self, options):
+    """Constructor.
+
+    Args:
+      options: Command line options.
+    """
+    self.options = options
+
+  def PostProcessDiff(self, diff):
+    """Return the diff with any special post processing this VCS needs, e.g.
+    to include an svn-style "Index:"."""
+    return diff
+
+  def GenerateDiff(self, args):
+    """Return the current diff as a string.
+
+    Args:
+      args: Extra arguments to pass to the diff command.
+    """
+    raise NotImplementedError(
+        "abstract method -- subclass %s must override" % self.__class__)
+
+  def GetUnknownFiles(self):
+    """Return a list of files unknown to the VCS."""
+    raise NotImplementedError(
+        "abstract method -- subclass %s must override" % self.__class__)
+
+  def CheckForUnknownFiles(self):
+    """Show an "are you sure?" prompt if there are unknown files."""
+    unknown_files = self.GetUnknownFiles()
+    if unknown_files:
+      print "The following files are not added to version control:"
+      for line in unknown_files:
+        print line
+      prompt = "Are you sure to continue?(y/N) "
+      answer = raw_input(prompt).strip()
+      if answer != "y":
+        ErrorExit("User aborted")
+
+  def GetBaseFile(self, filename):
+    """Get the content of the upstream version of a file.
+
+    Returns:
+      A tuple (base_content, new_content, is_binary, status)
+        base_content: The contents of the base file.
+        new_content: For text files, this is empty.  For binary files, this is
+          the contents of the new file, since the diff output won't contain
+          information to reconstruct the current file.
+        is_binary: True iff the file is binary.
+        status: The status of the file.
+    """
+
+    raise NotImplementedError(
+        "abstract method -- subclass %s must override" % self.__class__)
+
+
+  def GetBaseFiles(self, diff):
+    """Helper that calls GetBase file for each file in the patch.
+
+    Returns:
+      A dictionary that maps from filename to GetBaseFile's tuple.  Filenames
+      are retrieved based on lines that start with "Index:" or
+      "Property changes on:".
+    """
+    files = {}
+    for line in diff.splitlines(True):
+      if line.startswith('Index:') or line.startswith('Property changes on:'):
+        unused, filename = line.split(':', 1)
+        # On Windows if a file has property changes its filename uses '\'
+        # instead of '/'.
+        filename = filename.strip().replace('\\', '/')
+        files[filename] = self.GetBaseFile(filename)
+    return files
+
+
+  def UploadBaseFiles(self, issue, rpc_server, patch_list, patchset, options,
+                      files):
+    """Uploads the base files (and if necessary, the current ones as well)."""
+
+    def UploadFile(filename, file_id, content, is_binary, status, is_base):
+      """Uploads a file to the server."""
+      file_too_large = False
+      if is_base:
+        type = "base"
+      else:
+        type = "current"
+      if len(content) > MAX_UPLOAD_SIZE:
+        print ("Not uploading the %s file for %s because it's too large." %
+               (type, filename))
+        file_too_large = True
+        content = ""
+      checksum = md5(content).hexdigest()
+      if options.verbose > 0 and not file_too_large:
+        print "Uploading %s file for %s" % (type, filename)
+      url = "/%d/upload_content/%d/%d" % (int(issue), int(patchset), file_id)
+      form_fields = [("filename", filename),
+                     ("status", status),
+                     ("checksum", checksum),
+                     ("is_binary", str(is_binary)),
+                     ("is_current", str(not is_base)),
+                    ]
+      if file_too_large:
+        form_fields.append(("file_too_large", "1"))
+      if options.email:
+        form_fields.append(("user", options.email))
+      ctype, body = EncodeMultipartFormData(form_fields,
+                                            [("data", filename, content)])
+      response_body = rpc_server.Send(url, body,
+                                      content_type=ctype)
+      if not response_body.startswith("OK"):
+        StatusUpdate("  --> %s" % response_body)
+        sys.exit(1)
+
+    patches = dict()
+    [patches.setdefault(v, k) for k, v in patch_list]
+    for filename in patches.keys():
+      base_content, new_content, is_binary, status = files[filename]
+      file_id_str = patches.get(filename)
+      if file_id_str.find("nobase") != -1:
+        base_content = None
+        file_id_str = file_id_str[file_id_str.rfind("_") + 1:]
+      file_id = int(file_id_str)
+      if base_content != None:
+        UploadFile(filename, file_id, base_content, is_binary, status, True)
+      if new_content != None:
+        UploadFile(filename, file_id, new_content, is_binary, status, False)
+
+  def IsImage(self, filename):
+    """Returns true if the filename has an image extension."""
+    mimetype =  mimetypes.guess_type(filename)[0]
+    if not mimetype:
+      return False
+    return mimetype.startswith("image/")
+
+  def IsBinary(self, filename):
+    """Returns true if the guessed mimetyped isnt't in text group."""
+    mimetype = mimetypes.guess_type(filename)[0]
+    if not mimetype:
+      return False  # e.g. README, "real" binaries usually have an extension
+    # special case for text files which don't start with text/
+    if mimetype in TEXT_MIMETYPES:
+      return False
+    return not mimetype.startswith("text/")
+
+
+class SubversionVCS(VersionControlSystem):
+  """Implementation of the VersionControlSystem interface for Subversion."""
+
+  def __init__(self, options):
+    super(SubversionVCS, self).__init__(options)
+    if self.options.revision:
+      match = re.match(r"(\d+)(:(\d+))?", self.options.revision)
+      if not match:
+        ErrorExit("Invalid Subversion revision %s." % self.options.revision)
+      self.rev_start = match.group(1)
+      self.rev_end = match.group(3)
+    else:
+      self.rev_start = self.rev_end = None
+    # Cache output from "svn list -r REVNO dirname".
+    # Keys: dirname, Values: 2-tuple (ouput for start rev and end rev).
+    self.svnls_cache = {}
+    # Base URL is required to fetch files deleted in an older revision.
+    # Result is cached to not guess it over and over again in GetBaseFile().
+    required = self.options.download_base or self.options.revision is not None
+    self.svn_base = self._GuessBase(required)
+
+  def GuessBase(self, required):
+    """Wrapper for _GuessBase."""
+    return self.svn_base
+
+  def _GuessBase(self, required):
+    """Returns the SVN base URL.
+
+    Args:
+      required: If true, exits if the url can't be guessed, otherwise None is
+        returned.
+    """
+    info = RunShell(["svn", "info"])
+    for line in info.splitlines():
+      words = line.split()
+      if len(words) == 2 and words[0] == "URL:":
+        url = words[1]
+        scheme, netloc, path, params, query, fragment = urlparse.urlparse(url)
+        username, netloc = urllib.splituser(netloc)
+        if username:
+          logging.info("Removed username from base URL")
+        if netloc.endswith("svn.python.org"):
+          if netloc == "svn.python.org":
+            if path.startswith("/projects/"):
+              path = path[9:]
+          elif netloc != "pythondev@svn.python.org":
+            ErrorExit("Unrecognized Python URL: %s" % url)
+          base = "http://svn.python.org/view/*checkout*%s/" % path
+          logging.info("Guessed Python base = %s", base)
+        elif netloc.endswith("svn.collab.net"):
+          if path.startswith("/repos/"):
+            path = path[6:]
+          base = "http://svn.collab.net/viewvc/*checkout*%s/" % path
+          logging.info("Guessed CollabNet base = %s", base)
+        elif netloc.endswith(".googlecode.com"):
+          path = path + "/"
+          base = urlparse.urlunparse(("http", netloc, path, params,
+                                      query, fragment))
+          logging.info("Guessed Google Code base = %s", base)
+        else:
+          path = path + "/"
+          base = urlparse.urlunparse((scheme, netloc, path, params,
+                                      query, fragment))
+          logging.info("Guessed base = %s", base)
+        return base
+    if required:
+      ErrorExit("Can't find URL in output from svn info")
+    return None
+
+  def GenerateDiff(self, args):
+    cmd = ["svn", "diff"]
+    if self.options.revision:
+      cmd += ["-r", self.options.revision]
+    cmd.extend(args)
+    data = RunShell(cmd)
+    count = 0
+    for line in data.splitlines():
+      if line.startswith("Index:") or line.startswith("Property changes on:"):
+        count += 1
+        logging.info(line)
+    if not count:
+      ErrorExit("No valid patches found in output from svn diff")
+    return data
+
+  def _CollapseKeywords(self, content, keyword_str):
+    """Collapses SVN keywords."""
+    # svn cat translates keywords but svn diff doesn't. As a result of this
+    # behavior patching.PatchChunks() fails with a chunk mismatch error.
+    # This part was originally written by the Review Board development team
+    # who had the same problem (http://reviews.review-board.org/r/276/).
+    # Mapping of keywords to known aliases
+    svn_keywords = {
+      # Standard keywords
+      'Date':                ['Date', 'LastChangedDate'],
+      'Revision':            ['Revision', 'LastChangedRevision', 'Rev'],
+      'Author':              ['Author', 'LastChangedBy'],
+      'HeadURL':             ['HeadURL', 'URL'],
+      'Id':                  ['Id'],
+
+      # Aliases
+      'LastChangedDate':     ['LastChangedDate', 'Date'],
+      'LastChangedRevision': ['LastChangedRevision', 'Rev', 'Revision'],
+      'LastChangedBy':       ['LastChangedBy', 'Author'],
+      'URL':                 ['URL', 'HeadURL'],
+    }
+
+    def repl(m):
+       if m.group(2):
+         return "$%s::%s$" % (m.group(1), " " * len(m.group(3)))
+       return "$%s$" % m.group(1)
+    keywords = [keyword
+                for name in keyword_str.split(" ")
+                for keyword in svn_keywords.get(name, [])]
+    return re.sub(r"\$(%s):(:?)([^\$]+)\$" % '|'.join(keywords), repl, content)
+
+  def GetUnknownFiles(self):
+    status = RunShell(["svn", "status", "--ignore-externals"], silent_ok=True)
+    unknown_files = []
+    for line in status.split("\n"):
+      if line and line[0] == "?":
+        unknown_files.append(line)
+    return unknown_files
+
+  def ReadFile(self, filename):
+    """Returns the contents of a file."""
+    file = open(filename, 'rb')
+    result = ""
+    try:
+      result = file.read()
+    finally:
+      file.close()
+    return result
+
+  def GetStatus(self, filename):
+    """Returns the status of a file."""
+    if not self.options.revision:
+      status = RunShell(["svn", "status", "--ignore-externals", filename])
+      if not status:
+        ErrorExit("svn status returned no output for %s" % filename)
+      status_lines = status.splitlines()
+      # If file is in a cl, the output will begin with
+      # "\n--- Changelist 'cl_name':\n".  See
+      # http://svn.collab.net/repos/svn/trunk/notes/changelist-design.txt
+      if (len(status_lines) == 3 and
+          not status_lines[0] and
+          status_lines[1].startswith("--- Changelist")):
+        status = status_lines[2]
+      else:
+        status = status_lines[0]
+    # If we have a revision to diff against we need to run "svn list"
+    # for the old and the new revision and compare the results to get
+    # the correct status for a file.
+    else:
+      dirname, relfilename = os.path.split(filename)
+      if dirname not in self.svnls_cache:
+        cmd = ["svn", "list", "-r", self.rev_start, dirname or "."]
+        out, returncode = RunShellWithReturnCode(cmd)
+        if returncode:
+          ErrorExit("Failed to get status for %s." % filename)
+        old_files = out.splitlines()
+        args = ["svn", "list"]
+        if self.rev_end:
+          args += ["-r", self.rev_end]
+        cmd = args + [dirname or "."]
+        out, returncode = RunShellWithReturnCode(cmd)
+        if returncode:
+          ErrorExit("Failed to run command %s" % cmd)
+        self.svnls_cache[dirname] = (old_files, out.splitlines())
+      old_files, new_files = self.svnls_cache[dirname]
+      if relfilename in old_files and relfilename not in new_files:
+        status = "D   "
+      elif relfilename in old_files and relfilename in new_files:
+        status = "M   "
+      else:
+        status = "A   "
+    return status
+
+  def GetBaseFile(self, filename):
+    status = self.GetStatus(filename)
+    base_content = None
+    new_content = None
+
+    # If a file is copied its status will be "A  +", which signifies
+    # "addition-with-history".  See "svn st" for more information.  We need to
+    # upload the original file or else diff parsing will fail if the file was
+    # edited.
+    if status[0] == "A" and status[3] != "+":
+      # We'll need to upload the new content if we're adding a binary file
+      # since diff's output won't contain it.
+      mimetype = RunShell(["svn", "propget", "svn:mime-type", filename],
+                          silent_ok=True)
+      base_content = ""
+      is_binary = bool(mimetype) and not mimetype.startswith("text/")
+      if is_binary and self.IsImage(filename):
+        new_content = self.ReadFile(filename)
+    elif (status[0] in ("M", "D", "R") or
+          (status[0] == "A" and status[3] == "+") or  # Copied file.
+          (status[0] == " " and status[1] == "M")):  # Property change.
+      args = []
+      if self.options.revision:
+        url = "%s/%s@%s" % (self.svn_base, filename, self.rev_start)
+      else:
+        # Don't change filename, it's needed later.
+        url = filename
+        args += ["-r", "BASE"]
+      cmd = ["svn"] + args + ["propget", "svn:mime-type", url]
+      mimetype, returncode = RunShellWithReturnCode(cmd)
+      if returncode:
+        # File does not exist in the requested revision.
+        # Reset mimetype, it contains an error message.
+        mimetype = ""
+      get_base = False
+      is_binary = bool(mimetype) and not mimetype.startswith("text/")
+      if status[0] == " ":
+        # Empty base content just to force an upload.
+        base_content = ""
+      elif is_binary:
+        if self.IsImage(filename):
+          get_base = True
+          if status[0] == "M":
+            if not self.rev_end:
+              new_content = self.ReadFile(filename)
+            else:
+              url = "%s/%s@%s" % (self.svn_base, filename, self.rev_end)
+              new_content = RunShell(["svn", "cat", url],
+                                     universal_newlines=True, silent_ok=True)
+        else:
+          base_content = ""
+      else:
+        get_base = True
+
+      if get_base:
+        if is_binary:
+          universal_newlines = False
+        else:
+          universal_newlines = True
+        if self.rev_start:
+          # "svn cat -r REV delete_file.txt" doesn't work. cat requires
+          # the full URL with "@REV" appended instead of using "-r" option.
+          url = "%s/%s@%s" % (self.svn_base, filename, self.rev_start)
+          base_content = RunShell(["svn", "cat", url],
+                                  universal_newlines=universal_newlines,
+                                  silent_ok=True)
+        else:
+          base_content, ret_code = RunShellWithReturnCode(
+            ["svn", "cat", filename], universal_newlines=universal_newlines)
+          if ret_code and status[0] == "R":
+            # It's a replaced file without local history (see issue208).
+            # The base file needs to be fetched from the server.
+            url = "%s/%s" % (self.svn_base, filename)
+            base_content = RunShell(["svn", "cat", url],
+                                    universal_newlines=universal_newlines,
+                                    silent_ok=True)
+          elif ret_code:
+            ErrorExit("Got error status from 'svn cat %s'" % filename)
+        if not is_binary:
+          args = []
+          if self.rev_start:
+            url = "%s/%s@%s" % (self.svn_base, filename, self.rev_start)
+          else:
+            url = filename
+            args += ["-r", "BASE"]
+          cmd = ["svn"] + args + ["propget", "svn:keywords", url]
+          keywords, returncode = RunShellWithReturnCode(cmd)
+          if keywords and not returncode:
+            base_content = self._CollapseKeywords(base_content, keywords)
+    else:
+      StatusUpdate("svn status returned unexpected output: %s" % status)
+      sys.exit(1)
+    return base_content, new_content, is_binary, status[0:5]
+
+
+class GitVCS(VersionControlSystem):
+  """Implementation of the VersionControlSystem interface for Git."""
+
+  def __init__(self, options):
+    super(GitVCS, self).__init__(options)
+    # Map of filename -> (hash before, hash after) of base file.
+    # Hashes for "no such file" are represented as None.
+    self.hashes = {}
+    # Map of new filename -> old filename for renames.
+    self.renames = {}
+
+  def PostProcessDiff(self, gitdiff):
+    """Converts the diff output to include an svn-style "Index:" line as well
+    as record the hashes of the files, so we can upload them along with our
+    diff."""
+    # Special used by git to indicate "no such content".
+    NULL_HASH = "0"*40
+
+    def IsFileNew(filename):
+      return filename in self.hashes and self.hashes[filename][0] is None
+
+    def AddSubversionPropertyChange(filename):
+      """Add svn's property change information into the patch if given file is
+      new file.
+
+      We use Subversion's auto-props setting to retrieve its property.
+      See http://svnbook.red-bean.com/en/1.1/ch07.html#svn-ch-7-sect-1.3.2 for
+      Subversion's [auto-props] setting.
+      """
+      if self.options.emulate_svn_auto_props and IsFileNew(filename):
+        svnprops = GetSubversionPropertyChanges(filename)
+        if svnprops:
+          svndiff.append("\n" + svnprops + "\n")
+
+    svndiff = []
+    filecount = 0
+    filename = None
+    for line in gitdiff.splitlines():
+      match = re.match(r"diff --git a/(.*) b/(.*)$", line)
+      if match:
+        # Add auto property here for previously seen file.
+        if filename is not None:
+          AddSubversionPropertyChange(filename)
+        filecount += 1
+        # Intentionally use the "after" filename so we can show renames.
+        filename = match.group(2)
+        svndiff.append("Index: %s\n" % filename)
+        if match.group(1) != match.group(2):
+          self.renames[match.group(2)] = match.group(1)
+      else:
+        # The "index" line in a git diff looks like this (long hashes elided):
+        #   index 82c0d44..b2cee3f 100755
+        # We want to save the left hash, as that identifies the base file.
+        match = re.match(r"index (\w+)\.\.(\w+)", line)
+        if match:
+          before, after = (match.group(1), match.group(2))
+          if before == NULL_HASH:
+            before = None
+          if after == NULL_HASH:
+            after = None
+          self.hashes[filename] = (before, after)
+      svndiff.append(line + "\n")
+    if not filecount:
+      ErrorExit("No valid patches found in output from git diff")
+    # Add auto property for the last seen file.
+    assert filename is not None
+    AddSubversionPropertyChange(filename)
+    return "".join(svndiff)
+
+  def GenerateDiff(self, extra_args):
+    extra_args = extra_args[:]
+    if self.options.revision:
+      extra_args = [self.options.revision] + extra_args
+
+    # --no-ext-diff is broken in some versions of Git, so try to work around
+    # this by overriding the environment (but there is still a problem if the
+    # git config key "diff.external" is used).
+    env = os.environ.copy()
+    if 'GIT_EXTERNAL_DIFF' in env: del env['GIT_EXTERNAL_DIFF']
+    return RunShell(["git", "diff", "--no-ext-diff", "--full-index", "-M"]
+                    + extra_args, env=env)
+
+  def GetUnknownFiles(self):
+    status = RunShell(["git", "ls-files", "--exclude-standard", "--others"],
+                      silent_ok=True)
+    return status.splitlines()
+
+  def GetFileContent(self, file_hash, is_binary):
+    """Returns the content of a file identified by its git hash."""
+    data, retcode = RunShellWithReturnCode(["git", "show", file_hash],
+                                            universal_newlines=not is_binary)
+    if retcode:
+      ErrorExit("Got error status from 'git show %s'" % file_hash)
+    return data
+
+  def GetBaseFile(self, filename):
+    hash_before, hash_after = self.hashes.get(filename, (None,None))
+    base_content = None
+    new_content = None
+    is_binary = self.IsBinary(filename)
+    status = None
+
+    if filename in self.renames:
+      status = "A +"  # Match svn attribute name for renames.
+      if filename not in self.hashes:
+        # If a rename doesn't change the content, we never get a hash.
+        base_content = RunShell(["git", "show", "HEAD:" + filename])
+    elif not hash_before:
+      status = "A"
+      base_content = ""
+    elif not hash_after:
+      status = "D"
+    else:
+      status = "M"
+
+    is_image = self.IsImage(filename)
+
+    # Grab the before/after content if we need it.
+    # We should include file contents if it's text or it's an image.
+    if not is_binary or is_image:
+      # Grab the base content if we don't have it already.
+      if base_content is None and hash_before:
+        base_content = self.GetFileContent(hash_before, is_binary)
+      # Only include the "after" file if it's an image; otherwise it
+      # it is reconstructed from the diff.
+      if is_image and hash_after:
+        new_content = self.GetFileContent(hash_after, is_binary)
+
+    return (base_content, new_content, is_binary, status)
+
+
+class MercurialVCS(VersionControlSystem):
+  """Implementation of the VersionControlSystem interface for Mercurial."""
+
+  def __init__(self, options, repo_dir):
+    super(MercurialVCS, self).__init__(options)
+    # Absolute path to repository (we can be in a subdir)
+    self.repo_dir = os.path.normpath(repo_dir)
+    # Compute the subdir
+    cwd = os.path.normpath(os.getcwd())
+    assert cwd.startswith(self.repo_dir)
+    self.subdir = cwd[len(self.repo_dir):].lstrip(r"\/")
+    if self.options.revision:
+      self.base_rev = self.options.revision
+    else:
+      self.base_rev = RunShell(["hg", "parent", "-q"]).split(':')[1].strip()
+
+  def _GetRelPath(self, filename):
+    """Get relative path of a file according to the current directory,
+    given its logical path in the repo."""
+    assert filename.startswith(self.subdir), (filename, self.subdir)
+    return filename[len(self.subdir):].lstrip(r"\/")
+
+  def GenerateDiff(self, extra_args):
+    # If no file specified, restrict to the current subdir
+    extra_args = extra_args or ["."]
+    cmd = ["hg", "diff", "--git", "-r", self.base_rev] + extra_args
+    data = RunShell(cmd, silent_ok=True)
+    svndiff = []
+    filecount = 0
+    for line in data.splitlines():
+      m = re.match("diff --git a/(\S+) b/(\S+)", line)
+      if m:
+        # Modify line to make it look like as it comes from svn diff.
+        # With this modification no changes on the server side are required
+        # to make upload.py work with Mercurial repos.
+        # NOTE: for proper handling of moved/copied files, we have to use
+        # the second filename.
+        filename = m.group(2)
+        svndiff.append("Index: %s" % filename)
+        svndiff.append("=" * 67)
+        filecount += 1
+        logging.info(line)
+      else:
+        svndiff.append(line)
+    if not filecount:
+      ErrorExit("No valid patches found in output from hg diff")
+    return "\n".join(svndiff) + "\n"
+
+  def GetUnknownFiles(self):
+    """Return a list of files unknown to the VCS."""
+    args = []
+    status = RunShell(["hg", "status", "--rev", self.base_rev, "-u", "."],
+        silent_ok=True)
+    unknown_files = []
+    for line in status.splitlines():
+      st, fn = line.split(" ", 1)
+      if st == "?":
+        unknown_files.append(fn)
+    return unknown_files
+
+  def GetBaseFile(self, filename):
+    # "hg status" and "hg cat" both take a path relative to the current subdir
+    # rather than to the repo root, but "hg diff" has given us the full path
+    # to the repo root.
+    base_content = ""
+    new_content = None
+    is_binary = False
+    oldrelpath = relpath = self._GetRelPath(filename)
+    # "hg status -C" returns two lines for moved/copied files, one otherwise
+    out = RunShell(["hg", "status", "-C", "--rev", self.base_rev, relpath])
+    out = out.splitlines()
+    # HACK: strip error message about missing file/directory if it isn't in
+    # the working copy
+    if out[0].startswith('%s: ' % relpath):
+      out = out[1:]
+    if len(out) > 1:
+      # Moved/copied => considered as modified, use old filename to
+      # retrieve base contents
+      oldrelpath = out[1].strip()
+      status = "M"
+    else:
+      status, _ = out[0].split(' ', 1)
+    if ":" in self.base_rev:
+      base_rev = self.base_rev.split(":", 1)[0]
+    else:
+      base_rev = self.base_rev
+    if status != "A":
+      base_content = RunShell(["hg", "cat", "-r", base_rev, oldrelpath],
+        silent_ok=True)
+      is_binary = "\0" in base_content  # Mercurial's heuristic
+    if status != "R":
+      new_content = open(relpath, "rb").read()
+      is_binary = is_binary or "\0" in new_content
+    if is_binary and base_content:
+      # Fetch again without converting newlines
+      base_content = RunShell(["hg", "cat", "-r", base_rev, oldrelpath],
+        silent_ok=True, universal_newlines=False)
+    if not is_binary or not self.IsImage(relpath):
+      new_content = None
+    return base_content, new_content, is_binary, status
+
+
+# NOTE: The SplitPatch function is duplicated in engine.py, keep them in sync.
+def SplitPatch(data):
+  """Splits a patch into separate pieces for each file.
+
+  Args:
+    data: A string containing the output of svn diff.
+
+  Returns:
+    A list of 2-tuple (filename, text) where text is the svn diff output
+      pertaining to filename.
+  """
+  patches = []
+  filename = None
+  diff = []
+  for line in data.splitlines(True):
+    new_filename = None
+    if line.startswith('Index:'):
+      unused, new_filename = line.split(':', 1)
+      new_filename = new_filename.strip()
+    elif line.startswith('Property changes on:'):
+      unused, temp_filename = line.split(':', 1)
+      # When a file is modified, paths use '/' between directories, however
+      # when a property is modified '\' is used on Windows.  Make them the same
+      # otherwise the file shows up twice.
+      temp_filename = temp_filename.strip().replace('\\', '/')
+      if temp_filename != filename:
+        # File has property changes but no modifications, create a new diff.
+        new_filename = temp_filename
+    if new_filename:
+      if filename and diff:
+        patches.append((filename, ''.join(diff)))
+      filename = new_filename
+      diff = [line]
+      continue
+    if diff is not None:
+      diff.append(line)
+  if filename and diff:
+    patches.append((filename, ''.join(diff)))
+  return patches
+
+
+def UploadSeparatePatches(issue, rpc_server, patchset, data, options):
+  """Uploads a separate patch for each file in the diff output.
+
+  Returns a list of [patch_key, filename] for each file.
+  """
+  patches = SplitPatch(data)
+  rv = []
+  for patch in patches:
+    if len(patch[1]) > MAX_UPLOAD_SIZE:
+      print ("Not uploading the patch for " + patch[0] +
+             " because the file is too large.")
+      continue
+    form_fields = [("filename", patch[0])]
+    if not options.download_base:
+      form_fields.append(("content_upload", "1"))
+    files = [("data", "data.diff", patch[1])]
+    ctype, body = EncodeMultipartFormData(form_fields, files)
+    url = "/%d/upload_patch/%d" % (int(issue), int(patchset))
+    print "Uploading patch for " + patch[0]
+    response_body = rpc_server.Send(url, body, content_type=ctype)
+    lines = response_body.splitlines()
+    if not lines or lines[0] != "OK":
+      StatusUpdate("  --> %s" % response_body)
+      sys.exit(1)
+    rv.append([lines[1], patch[0]])
+  return rv
+
+
+def GuessVCSName():
+  """Helper to guess the version control system.
+
+  This examines the current directory, guesses which VersionControlSystem
+  we're using, and returns an string indicating which VCS is detected.
+
+  Returns:
+    A pair (vcs, output).  vcs is a string indicating which VCS was detected
+    and is one of VCS_GIT, VCS_MERCURIAL, VCS_SUBVERSION, or VCS_UNKNOWN.
+    output is a string containing any interesting output from the vcs
+    detection routine, or None if there is nothing interesting.
+  """
+  # Mercurial has a command to get the base directory of a repository
+  # Try running it, but don't die if we don't have hg installed.
+  # NOTE: we try Mercurial first as it can sit on top of an SVN working copy.
+  try:
+    out, returncode = RunShellWithReturnCode(["hg", "root"])
+    if returncode == 0:
+      return (VCS_MERCURIAL, out.strip())
+  except OSError, (errno, message):
+    if errno != 2:  # ENOENT -- they don't have hg installed.
+      raise
+
+  # Subversion has a .svn in all working directories.
+  if os.path.isdir('.svn'):
+    logging.info("Guessed VCS = Subversion")
+    return (VCS_SUBVERSION, None)
+
+  # Git has a command to test if you're in a git tree.
+  # Try running it, but don't die if we don't have git installed.
+  try:
+    out, returncode = RunShellWithReturnCode(["git", "rev-parse",
+                                              "--is-inside-work-tree"])
+    if returncode == 0:
+      return (VCS_GIT, None)
+  except OSError, (errno, message):
+    if errno != 2:  # ENOENT -- they don't have git installed.
+      raise
+
+  return (VCS_UNKNOWN, None)
+
+
+def GuessVCS(options):
+  """Helper to guess the version control system.
+
+  This verifies any user-specified VersionControlSystem (by command line
+  or environment variable).  If the user didn't specify one, this examines
+  the current directory, guesses which VersionControlSystem we're using,
+  and returns an instance of the appropriate class.  Exit with an error
+  if we can't figure it out.
+
+  Returns:
+    A VersionControlSystem instance. Exits if the VCS can't be guessed.
+  """
+  vcs = options.vcs
+  if not vcs:
+    vcs = os.environ.get("CODEREVIEW_VCS")
+  if vcs:
+    v = VCS_ABBREVIATIONS.get(vcs.lower())
+    if v is None:
+      ErrorExit("Unknown version control system %r specified." % vcs)
+    (vcs, extra_output) = (v, None)
+  else:
+    (vcs, extra_output) = GuessVCSName()
+
+  if vcs == VCS_MERCURIAL:
+    if extra_output is None:
+      extra_output = RunShell(["hg", "root"]).strip()
+    return MercurialVCS(options, extra_output)
+  elif vcs == VCS_SUBVERSION:
+    return SubversionVCS(options)
+  elif vcs == VCS_GIT:
+    return GitVCS(options)
+
+  ErrorExit(("Could not guess version control system. "
+             "Are you in a working copy directory?"))
+
+
+def CheckReviewer(reviewer):
+  """Validate a reviewer -- either a nickname or an email addres.
+
+  Args:
+    reviewer: A nickname or an email address.
+
+  Calls ErrorExit() if it is an invalid email address.
+  """
+  if "@" not in reviewer:
+    return  # Assume nickname
+  parts = reviewer.split("@")
+  if len(parts) > 2:
+    ErrorExit("Invalid email address: %r" % reviewer)
+  assert len(parts) == 2
+  if "." not in parts[1]:
+    ErrorExit("Invalid email address: %r" % reviewer)
+
+
+def LoadSubversionAutoProperties():
+  """Returns the content of [auto-props] section of Subversion's config file as
+  a dictionary.
+
+  Returns:
+    A dictionary whose key-value pair corresponds the [auto-props] section's
+      key-value pair.
+    In following cases, returns empty dictionary:
+      - config file doesn't exist, or
+      - 'enable-auto-props' is not set to 'true-like-value' in [miscellany].
+  """
+  # Todo(hayato): Windows users might use different path for configuration file.
+  subversion_config = os.path.expanduser("~/.subversion/config")
+  if not os.path.exists(subversion_config):
+    return {}
+  config = ConfigParser.ConfigParser()
+  config.read(subversion_config)
+  if (config.has_section("miscellany") and
+      config.has_option("miscellany", "enable-auto-props") and
+      config.getboolean("miscellany", "enable-auto-props") and
+      config.has_section("auto-props")):
+    props = {}
+    for file_pattern in config.options("auto-props"):
+      props[file_pattern] = ParseSubversionPropertyValues(
+        config.get("auto-props", file_pattern))
+    return props
+  else:
+    return {}
+
+def ParseSubversionPropertyValues(props):
+  """Parse the given property value which comes from [auto-props] section and
+  returns a list whose element is a (svn_prop_key, svn_prop_value) pair.
+
+  See the following doctest for example.
+
+  >>> ParseSubversionPropertyValues('svn:eol-style=LF')
+  [('svn:eol-style', 'LF')]
+  >>> ParseSubversionPropertyValues('svn:mime-type=image/jpeg')
+  [('svn:mime-type', 'image/jpeg')]
+  >>> ParseSubversionPropertyValues('svn:eol-style=LF;svn:executable')
+  [('svn:eol-style', 'LF'), ('svn:executable', '*')]
+  """
+  key_value_pairs = []
+  for prop in props.split(";"):
+    key_value = prop.split("=")
+    assert len(key_value) <= 2
+    if len(key_value) == 1:
+      # If value is not given, use '*' as a Subversion's convention.
+      key_value_pairs.append((key_value[0], "*"))
+    else:
+      key_value_pairs.append((key_value[0], key_value[1]))
+  return key_value_pairs
+
+
+def GetSubversionPropertyChanges(filename):
+  """Return a Subversion's 'Property changes on ...' string, which is used in
+  the patch file.
+
+  Args:
+    filename: filename whose property might be set by [auto-props] config.
+
+  Returns:
+    A string like 'Property changes on |filename| ...' if given |filename|
+      matches any entries in [auto-props] section. None, otherwise.
+  """
+  global svn_auto_props_map
+  if svn_auto_props_map is None:
+    svn_auto_props_map = LoadSubversionAutoProperties()
+
+  all_props = []
+  for file_pattern, props in svn_auto_props_map.items():
+    if fnmatch.fnmatch(filename, file_pattern):
+      all_props.extend(props)
+  if all_props:
+    return FormatSubversionPropertyChanges(filename, all_props)
+  return None
+
+
+def FormatSubversionPropertyChanges(filename, props):
+  """Returns Subversion's 'Property changes on ...' strings using given filename
+  and properties.
+
+  Args:
+    filename: filename
+    props: A list whose element is a (svn_prop_key, svn_prop_value) pair.
+
+  Returns:
+    A string which can be used in the patch file for Subversion.
+
+  See the following doctest for example.
+
+  >>> print FormatSubversionPropertyChanges('foo.cc', [('svn:eol-style', 'LF')])
+  Property changes on: foo.cc
+  ___________________________________________________________________
+  Added: svn:eol-style
+     + LF
+  <BLANKLINE>
+  """
+  prop_changes_lines = [
+    "Property changes on: %s" % filename,
+    "___________________________________________________________________"]
+  for key, value in props:
+    prop_changes_lines.append("Added: " + key)
+    prop_changes_lines.append("   + " + value)
+  return "\n".join(prop_changes_lines) + "\n"
+
+
+def RealMain(argv, data=None):
+  """The real main function.
+
+  Args:
+    argv: Command line arguments.
+    data: Diff contents. If None (default) the diff is generated by
+      the VersionControlSystem implementation returned by GuessVCS().
+
+  Returns:
+    A 2-tuple (issue id, patchset id).
+    The patchset id is None if the base files are not uploaded by this
+    script (applies only to SVN checkouts).
+  """
+  logging.basicConfig(format=("%(asctime).19s %(levelname)s %(filename)s:"
+                              "%(lineno)s %(message)s "))
+  os.environ['LC_ALL'] = 'C'
+  options, args = parser.parse_args(argv[1:])
+  global verbosity
+  verbosity = options.verbose
+  if verbosity >= 3:
+    logging.getLogger().setLevel(logging.DEBUG)
+  elif verbosity >= 2:
+    logging.getLogger().setLevel(logging.INFO)
+
+  vcs = GuessVCS(options)
+
+  base = options.base_url
+  if isinstance(vcs, SubversionVCS):
+    # Guessing the base field is only supported for Subversion.
+    # Note: Fetching base files may become deprecated in future releases.
+    guessed_base = vcs.GuessBase(options.download_base)
+    if base:
+      if guessed_base and base != guessed_base:
+        print "Using base URL \"%s\" from --base_url instead of \"%s\"" % \
+            (base, guessed_base)
+    else:
+      base = guessed_base
+
+  if not base and options.download_base:
+    options.download_base = True
+    logging.info("Enabled upload of base file")
+  if not options.assume_yes:
+    vcs.CheckForUnknownFiles()
+  if data is None:
+    data = vcs.GenerateDiff(args)
+  data = vcs.PostProcessDiff(data)
+  files = vcs.GetBaseFiles(data)
+  if verbosity >= 1:
+    print "Upload server:", options.server, "(change with -s/--server)"
+  if options.issue:
+    prompt = "Message describing this patch set: "
+  else:
+    prompt = "New issue subject: "
+  message = options.message or raw_input(prompt).strip()
+  if not message:
+    ErrorExit("A non-empty message is required")
+  rpc_server = GetRpcServer(options.server,
+                            options.email,
+                            options.host,
+                            options.save_cookies,
+                            options.account_type)
+  form_fields = [("subject", message)]
+  if base:
+    form_fields.append(("base", base))
+  if options.issue:
+    form_fields.append(("issue", str(options.issue)))
+  if options.email:
+    form_fields.append(("user", options.email))
+  if options.reviewers:
+    for reviewer in options.reviewers.split(','):
+      CheckReviewer(reviewer)
+    form_fields.append(("reviewers", options.reviewers))
+  if options.cc:
+    for cc in options.cc.split(','):
+      CheckReviewer(cc)
+    form_fields.append(("cc", options.cc))
+  description = options.description
+  if options.description_file:
+    if options.description:
+      ErrorExit("Can't specify description and description_file")
+    file = open(options.description_file, 'r')
+    description = file.read()
+    file.close()
+  if description:
+    form_fields.append(("description", description))
+  # Send a hash of all the base file so the server can determine if a copy
+  # already exists in an earlier patchset.
+  base_hashes = ""
+  for file, info in files.iteritems():
+    if not info[0] is None:
+      checksum = md5(info[0]).hexdigest()
+      if base_hashes:
+        base_hashes += "|"
+      base_hashes += checksum + ":" + file
+  form_fields.append(("base_hashes", base_hashes))
+  if options.private:
+    if options.issue:
+      print "Warning: Private flag ignored when updating an existing issue."
+    else:
+      form_fields.append(("private", "1"))
+  # If we're uploading base files, don't send the email before the uploads, so
+  # that it contains the file status.
+  if options.send_mail and options.download_base:
+    form_fields.append(("send_mail", "1"))
+  if not options.download_base:
+    form_fields.append(("content_upload", "1"))
+  if len(data) > MAX_UPLOAD_SIZE:
+    print "Patch is large, so uploading file patches separately."
+    uploaded_diff_file = []
+    form_fields.append(("separate_patches", "1"))
+  else:
+    uploaded_diff_file = [("data", "data.diff", data)]
+  ctype, body = EncodeMultipartFormData(form_fields, uploaded_diff_file)
+  response_body = rpc_server.Send("/upload", body, content_type=ctype)
+  patchset = None
+  if not options.download_base or not uploaded_diff_file:
+    lines = response_body.splitlines()
+    if len(lines) >= 2:
+      msg = lines[0]
+      patchset = lines[1].strip()
+      patches = [x.split(" ", 1) for x in lines[2:]]
+    else:
+      msg = response_body
+  else:
+    msg = response_body
+  StatusUpdate(msg)
+  if not response_body.startswith("Issue created.") and \
+  not response_body.startswith("Issue updated."):
+    sys.exit(0)
+  issue = msg[msg.rfind("/")+1:]
+
+  if not uploaded_diff_file:
+    result = UploadSeparatePatches(issue, rpc_server, patchset, data, options)
+    if not options.download_base:
+      patches = result
+
+  if not options.download_base:
+    vcs.UploadBaseFiles(issue, rpc_server, patches, patchset, options, files)
+    if options.send_mail:
+      rpc_server.Send("/" + issue + "/mail", payload="")
+  return issue, patchset
+
+
+def main():
+  try:
+    RealMain(sys.argv)
+  except KeyboardInterrupt:
+    print
+    StatusUpdate("Interrupted.")
+    sys.exit(1)
+
+
+if __name__ == "__main__":
+  main()