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diff --git a/python/google/protobuf/text_encoding.py b/python/google/protobuf/text_encoding.py
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+# Protocol Buffers - Google's data interchange format
+# Copyright 2008 Google Inc.  All rights reserved.
+# https://developers.google.com/protocol-buffers/
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#PY25 compatible for GAE.
+#
+"""Encoding related utilities."""
+
+import re
+import sys  ##PY25
+
+# Lookup table for utf8
+_cescape_utf8_to_str = [chr(i) for i in xrange(0, 256)]
+_cescape_utf8_to_str[9] = r'\t'  # optional escape
+_cescape_utf8_to_str[10] = r'\n'  # optional escape
+_cescape_utf8_to_str[13] = r'\r'  # optional escape
+_cescape_utf8_to_str[39] = r"\'"  # optional escape
+
+_cescape_utf8_to_str[34] = r'\"'  # necessary escape
+_cescape_utf8_to_str[92] = r'\\'  # necessary escape
+
+# Lookup table for non-utf8, with necessary escapes at (o >= 127 or o < 32)
+_cescape_byte_to_str = ([r'\%03o' % i for i in xrange(0, 32)] +
+                        [chr(i) for i in xrange(32, 127)] +
+                        [r'\%03o' % i for i in xrange(127, 256)])
+_cescape_byte_to_str[9] = r'\t'  # optional escape
+_cescape_byte_to_str[10] = r'\n'  # optional escape
+_cescape_byte_to_str[13] = r'\r'  # optional escape
+_cescape_byte_to_str[39] = r"\'"  # optional escape
+
+_cescape_byte_to_str[34] = r'\"'  # necessary escape
+_cescape_byte_to_str[92] = r'\\'  # necessary escape
+
+
+def CEscape(text, as_utf8):
+  """Escape a bytes string for use in an ascii protocol buffer.
+
+  text.encode('string_escape') does not seem to satisfy our needs as it
+  encodes unprintable characters using two-digit hex escapes whereas our
+  C++ unescaping function allows hex escapes to be any length.  So,
+  "\0011".encode('string_escape') ends up being "\\x011", which will be
+  decoded in C++ as a single-character string with char code 0x11.
+
+  Args:
+    text: A byte string to be escaped
+    as_utf8: Specifies if result should be returned in UTF-8 encoding
+  Returns:
+    Escaped string
+  """
+  # PY3 hack: make Ord work for str and bytes:
+  # //platforms/networking/data uses unicode here, hence basestring.
+  Ord = ord if isinstance(text, basestring) else lambda x: x
+  if as_utf8:
+    return ''.join(_cescape_utf8_to_str[Ord(c)] for c in text)
+  return ''.join(_cescape_byte_to_str[Ord(c)] for c in text)
+
+
+_CUNESCAPE_HEX = re.compile(r'(\\+)x([0-9a-fA-F])(?![0-9a-fA-F])')
+_cescape_highbit_to_str = ([chr(i) for i in range(0, 127)] +
+                           [r'\%03o' % i for i in range(127, 256)])
+
+
+def CUnescape(text):
+  """Unescape a text string with C-style escape sequences to UTF-8 bytes."""
+
+  def ReplaceHex(m):
+    # Only replace the match if the number of leading back slashes is odd. i.e.
+    # the slash itself is not escaped.
+    if len(m.group(1)) & 1:
+      return m.group(1) + 'x0' + m.group(2)
+    return m.group(0)
+
+  # This is required because the 'string_escape' encoding doesn't
+  # allow single-digit hex escapes (like '\xf').
+  result = _CUNESCAPE_HEX.sub(ReplaceHex, text)
+
+  if sys.version_info[0] < 3:  ##PY25
+##!PY25  if str is bytes:  # PY2
+    return result.decode('string_escape')
+  result = ''.join(_cescape_highbit_to_str[ord(c)] for c in result)
+  return (result.encode('ascii')  # Make it bytes to allow decode.
+          .decode('unicode_escape')
+          # Make it bytes again to return the proper type.
+          .encode('raw_unicode_escape'))