Submit recent changes from internal branch. See CHANGES.txt for more details.

10 files changed, 2571 insertions, 67 deletions

diff --git a/python/google/protobuf/internal/api_implementation.py b/python/google/protobuf/internal/api_implementation.py
new file mode 100755
index 00000000..b3e412e2
--- /dev/null
+++ b/python/google/protobuf/internal/api_implementation.py
@@ -0,0 +1,64 @@
+# Protocol Buffers - Google's data interchange format
+# Copyright 2008 Google Inc.  All rights reserved.
+# http://code.google.com/p/protobuf/
+#
+# 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.
+
+"""
+This module is the central entity that determines which implementation of the
+API is used.
+"""
+
+__author__ = 'petar@google.com (Petar Petrov)'
+
+import os
+# This environment variable can be used to switch to a certain implementation
+# of the Python API. Right now only 'python' and 'cpp' are valid values. Any
+# other value will be ignored.
+_implementation_type = os.getenv('PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION',
+                                 'python')
+
+
+if _implementation_type != 'python':
+  # For now, by default use the pure-Python implementation.
+  # The code below checks if the C extension is available and
+  # uses it if it is available.
+  _implementation_type = 'cpp'
+  ## Determine automatically which implementation to use.
+  #try:
+  #  from google.protobuf.internal import cpp_message
+  #  _implementation_type = 'cpp'
+  #except ImportError, e:
+  #  _implementation_type = 'python'
+
+
+# Usage of this function is discouraged. Clients shouldn't care which
+# implementation of the API is in use. Note that there is no guarantee
+# that differences between APIs will be maintained.
+# Please don't use this function if possible.
+def Type():
+  return _implementation_type
diff --git a/python/google/protobuf/internal/containers.py b/python/google/protobuf/internal/containers.py
index 5cc7d6d0..097a3c26 100755
--- a/python/google/protobuf/internal/containers.py
+++ b/python/google/protobuf/internal/containers.py
@@ -72,9 +72,15 @@ class BaseContainer(object):
     # The concrete classes should define __eq__.
     return not self == other
 
+  def __hash__(self):
+    raise TypeError('unhashable object')
+
   def __repr__(self):
     return repr(self._values)
 
+  def sort(self, sort_function=cmp):
+    self._values.sort(sort_function)
+
 
 class RepeatedScalarFieldContainer(BaseContainer):
 
@@ -198,28 +204,37 @@ class RepeatedCompositeFieldContainer(BaseContainer):
     super(RepeatedCompositeFieldContainer, self).__init__(message_listener)
     self._message_descriptor = message_descriptor
 
-  def add(self):
-    new_element = self._message_descriptor._concrete_class()
+  def add(self, **kwargs):
+    """Adds a new element at the end of the list and returns it. Keyword
+    arguments may be used to initialize the element.
+    """
+    new_element = self._message_descriptor._concrete_class(**kwargs)
     new_element._SetListener(self._message_listener)
     self._values.append(new_element)
     if not self._message_listener.dirty:
       self._message_listener.Modified()
     return new_element
 
-  def MergeFrom(self, other):
-    """Appends the contents of another repeated field of the same type to this
-    one, copying each individual message.
+  def extend(self, elem_seq):
+    """Extends by appending the given sequence of elements of the same type
+    as this one, copying each individual message.
     """
     message_class = self._message_descriptor._concrete_class
     listener = self._message_listener
     values = self._values
-    for message in other._values:
+    for message in elem_seq:
       new_element = message_class()
       new_element._SetListener(listener)
       new_element.MergeFrom(message)
       values.append(new_element)
     listener.Modified()
 
+  def MergeFrom(self, other):
+    """Appends the contents of another repeated field of the same type to this
+    one, copying each individual message.
+    """
+    self.extend(other._values)
+
   def __getslice__(self, start, stop):
     """Retrieves the subset of items from between the specified indices."""
     return self._values[start:stop]
diff --git a/python/google/protobuf/internal/cpp_message.py b/python/google/protobuf/internal/cpp_message.py
new file mode 100755
index 00000000..3f426502
--- /dev/null
+++ b/python/google/protobuf/internal/cpp_message.py
@@ -0,0 +1,616 @@
+# Protocol Buffers - Google's data interchange format
+# Copyright 2008 Google Inc.  All rights reserved.
+# http://code.google.com/p/protobuf/
+#
+# 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.
+
+"""Contains helper functions used to create protocol message classes from
+Descriptor objects at runtime backed by the protocol buffer C++ API.
+"""
+
+__author__ = 'petar@google.com (Petar Petrov)'
+
+import operator
+from google.protobuf.internal import _net_proto2___python
+from google.protobuf import message
+
+
+_LABEL_REPEATED = _net_proto2___python.LABEL_REPEATED
+_LABEL_OPTIONAL = _net_proto2___python.LABEL_OPTIONAL
+_CPPTYPE_MESSAGE = _net_proto2___python.CPPTYPE_MESSAGE
+_TYPE_MESSAGE = _net_proto2___python.TYPE_MESSAGE
+
+
+def GetDescriptorPool():
+  """Creates a new DescriptorPool C++ object."""
+  return _net_proto2___python.NewCDescriptorPool()
+
+
+_pool = GetDescriptorPool()
+
+
+def GetFieldDescriptor(full_field_name):
+  """Searches for a field descriptor given a full field name."""
+  return _pool.FindFieldByName(full_field_name)
+
+
+def BuildFile(content):
+  """Registers a new proto file in the underlying C++ descriptor pool."""
+  _net_proto2___python.BuildFile(content)
+
+
+def GetExtensionDescriptor(full_extension_name):
+  """Searches for extension descriptor given a full field name."""
+  return _pool.FindExtensionByName(full_extension_name)
+
+
+def NewCMessage(full_message_name):
+  """Creates a new C++ protocol message by its name."""
+  return _net_proto2___python.NewCMessage(full_message_name)
+
+
+def ScalarProperty(cdescriptor):
+  """Returns a scalar property for the given descriptor."""
+
+  def Getter(self):
+    return self._cmsg.GetScalar(cdescriptor)
+
+  def Setter(self, value):
+    self._cmsg.SetScalar(cdescriptor, value)
+
+  return property(Getter, Setter)
+
+
+def CompositeProperty(cdescriptor, message_type):
+  """Returns a Python property the given composite field."""
+
+  def Getter(self):
+    sub_message = self._composite_fields.get(cdescriptor.name, None)
+    if sub_message is None:
+      cmessage = self._cmsg.NewSubMessage(cdescriptor)
+      sub_message = message_type._concrete_class(__cmessage=cmessage)
+      self._composite_fields[cdescriptor.name] = sub_message
+    return sub_message
+
+  return property(Getter)
+
+
+class RepeatedScalarContainer(object):
+  """Container for repeated scalar fields."""
+
+  __slots__ = ['_message', '_cfield_descriptor', '_cmsg']
+
+  def __init__(self, msg, cfield_descriptor):
+    self._message = msg
+    self._cmsg = msg._cmsg
+    self._cfield_descriptor = cfield_descriptor
+
+  def append(self, value):
+    self._cmsg.AddRepeatedScalar(
+        self._cfield_descriptor, value)
+
+  def extend(self, sequence):
+    for element in sequence:
+      self.append(element)
+
+  def insert(self, key, value):
+    values = self[slice(None, None, None)]
+    values.insert(key, value)
+    self._cmsg.AssignRepeatedScalar(self._cfield_descriptor, values)
+
+  def remove(self, value):
+    values = self[slice(None, None, None)]
+    values.remove(value)
+    self._cmsg.AssignRepeatedScalar(self._cfield_descriptor, values)
+
+  def __setitem__(self, key, value):
+    values = self[slice(None, None, None)]
+    values[key] = value
+    self._cmsg.AssignRepeatedScalar(self._cfield_descriptor, values)
+
+  def __getitem__(self, key):
+    return self._cmsg.GetRepeatedScalar(self._cfield_descriptor, key)
+
+  def __delitem__(self, key):
+    self._cmsg.DeleteRepeatedField(self._cfield_descriptor, key)
+
+  def __len__(self):
+    return len(self[slice(None, None, None)])
+
+  def __eq__(self, other):
+    if self is other:
+      return True
+    if not operator.isSequenceType(other):
+      raise TypeError(
+          'Can only compare repeated scalar fields against sequences.')
+    # We are presumably comparing against some other sequence type.
+    return other == self[slice(None, None, None)]
+
+  def __ne__(self, other):
+    return not self == other
+
+  def __hash__(self):
+    raise TypeError('unhashable object')
+
+  def sort(self, sort_function=cmp):
+    values = self[slice(None, None, None)]
+    values.sort(sort_function)
+    self._cmsg.AssignRepeatedScalar(self._cfield_descriptor, values)
+
+
+def RepeatedScalarProperty(cdescriptor):
+  """Returns a Python property the given repeated scalar field."""
+
+  def Getter(self):
+    container = self._composite_fields.get(cdescriptor.name, None)
+    if container is None:
+      container = RepeatedScalarContainer(self, cdescriptor)
+      self._composite_fields[cdescriptor.name] = container
+    return container
+
+  def Setter(self, new_value):
+    raise AttributeError('Assignment not allowed to repeated field '
+                         '"%s" in protocol message object.' % cdescriptor.name)
+
+  doc = 'Magic attribute generated for "%s" proto field.' % cdescriptor.name
+  return property(Getter, Setter, doc=doc)
+
+
+class RepeatedCompositeContainer(object):
+  """Container for repeated composite fields."""
+
+  __slots__ = ['_message', '_subclass', '_cfield_descriptor', '_cmsg']
+
+  def __init__(self, msg, cfield_descriptor, subclass):
+    self._message = msg
+    self._cmsg = msg._cmsg
+    self._subclass = subclass
+    self._cfield_descriptor = cfield_descriptor
+
+  def add(self, **kwargs):
+    cmessage = self._cmsg.AddMessage(self._cfield_descriptor)
+    return self._subclass(__cmessage=cmessage, __owner=self._message, **kwargs)
+
+  def extend(self, elem_seq):
+    """Extends by appending the given sequence of elements of the same type
+    as this one, copying each individual message.
+    """
+    for message in elem_seq:
+      self.add().MergeFrom(message)
+
+  def MergeFrom(self, other):
+    for message in other[:]:
+      self.add().MergeFrom(message)
+
+  def __getitem__(self, key):
+    cmessages = self._cmsg.GetRepeatedMessage(
+        self._cfield_descriptor, key)
+    subclass = self._subclass
+    if not isinstance(cmessages, list):
+      return subclass(__cmessage=cmessages, __owner=self._message)
+
+    return [subclass(__cmessage=m, __owner=self._message) for m in cmessages]
+
+  def __delitem__(self, key):
+    self._cmsg.DeleteRepeatedField(
+        self._cfield_descriptor, key)
+
+  def __len__(self):
+    return self._cmsg.FieldLength(self._cfield_descriptor)
+
+  def __eq__(self, other):
+    """Compares the current instance with another one."""
+    if self is other:
+      return True
+    if not isinstance(other, self.__class__):
+      raise TypeError('Can only compare repeated composite fields against '
+                      'other repeated composite fields.')
+    messages = self[slice(None, None, None)]
+    other_messages = other[slice(None, None, None)]
+    return messages == other_messages
+
+  def __hash__(self):
+    raise TypeError('unhashable object')
+
+  def sort(self, sort_function=cmp):
+    messages = []
+    for index in range(len(self)):
+      # messages[i][0] is where the i-th element of the new array has to come
+      # from.
+      # messages[i][1] is where the i-th element of the old array has to go.
+      messages.append([index, 0, self[index]])
+    messages.sort(lambda x,y: sort_function(x[2], y[2]))
+
+    # Remember which position each elements has to move to.
+    for i in range(len(messages)):
+      messages[messages[i][0]][1] = i
+
+    # Apply the transposition.
+    for i in range(len(messages)):
+      from_position = messages[i][0]
+      if i == from_position:
+        continue
+      self._cmsg.SwapRepeatedFieldElements(
+          self._cfield_descriptor, i, from_position)
+      messages[messages[i][1]][0] = from_position
+
+
+def RepeatedCompositeProperty(cdescriptor, message_type):
+  """Returns a Python property for the given repeated composite field."""
+
+  def Getter(self):
+    container = self._composite_fields.get(cdescriptor.name, None)
+    if container is None:
+      container = RepeatedCompositeContainer(
+          self, cdescriptor, message_type._concrete_class)
+      self._composite_fields[cdescriptor.name] = container
+    return container
+
+  def Setter(self, new_value):
+    raise AttributeError('Assignment not allowed to repeated field '
+                         '"%s" in protocol message object.' % cdescriptor.name)
+
+  doc = 'Magic attribute generated for "%s" proto field.' % cdescriptor.name
+  return property(Getter, Setter, doc=doc)
+
+
+class ExtensionDict(object):
+  """Extension dictionary added to each protocol message."""
+
+  def __init__(self, msg):
+    self._message = msg
+    self._cmsg = msg._cmsg
+    self._values = {}
+
+  def __setitem__(self, extension, value):
+    from google.protobuf import descriptor
+    if not isinstance(extension, descriptor.FieldDescriptor):
+      raise KeyError('Bad extension %r.' % (extension,))
+    cdescriptor = extension._cdescriptor
+    if (cdescriptor.label != _LABEL_OPTIONAL or
+        cdescriptor.cpp_type == _CPPTYPE_MESSAGE):
+      raise TypeError('Extension %r is repeated and/or a composite type.' % (
+          extension.full_name,))
+    self._cmsg.SetScalar(cdescriptor, value)
+    self._values[extension] = value
+
+  def __getitem__(self, extension):
+    from google.protobuf import descriptor
+    if not isinstance(extension, descriptor.FieldDescriptor):
+      raise KeyError('Bad extension %r.' % (extension,))
+
+    cdescriptor = extension._cdescriptor
+    if (cdescriptor.label != _LABEL_REPEATED and
+        cdescriptor.cpp_type != _CPPTYPE_MESSAGE):
+      return self._cmsg.GetScalar(cdescriptor)
+
+    ext = self._values.get(extension, None)
+    if ext is not None:
+      return ext
+
+    ext = self._CreateNewHandle(extension)
+    self._values[extension] = ext
+    return ext
+
+  def ClearExtension(self, extension):
+    from google.protobuf import descriptor
+    if not isinstance(extension, descriptor.FieldDescriptor):
+      raise KeyError('Bad extension %r.' % (extension,))
+    self._cmsg.ClearFieldByDescriptor(extension._cdescriptor)
+    if extension in self._values:
+      del self._values[extension]
+
+  def HasExtension(self, extension):
+    from google.protobuf import descriptor
+    if not isinstance(extension, descriptor.FieldDescriptor):
+      raise KeyError('Bad extension %r.' % (extension,))
+    return self._cmsg.HasFieldByDescriptor(extension._cdescriptor)
+
+  def _FindExtensionByName(self, name):
+    """Tries to find a known extension with the specified name.
+
+    Args:
+      name: Extension full name.
+
+    Returns:
+      Extension field descriptor.
+    """
+    return self._message._extensions_by_name.get(name, None)
+
+  def _CreateNewHandle(self, extension):
+    cdescriptor = extension._cdescriptor
+    if (cdescriptor.label != _LABEL_REPEATED and
+        cdescriptor.cpp_type == _CPPTYPE_MESSAGE):
+      cmessage = self._cmsg.NewSubMessage(cdescriptor)
+      return extension.message_type._concrete_class(__cmessage=cmessage)
+
+    if cdescriptor.label == _LABEL_REPEATED:
+      if cdescriptor.cpp_type == _CPPTYPE_MESSAGE:
+        return RepeatedCompositeContainer(
+            self._message, cdescriptor, extension.message_type._concrete_class)
+      else:
+        return RepeatedScalarContainer(self._message, cdescriptor)
+    # This shouldn't happen!
+    assert False
+    return None
+
+
+def NewMessage(message_descriptor, dictionary):
+  """Creates a new protocol message *class*."""
+  _AddClassAttributesForNestedExtensions(message_descriptor, dictionary)
+  _AddEnumValues(message_descriptor, dictionary)
+  _AddDescriptors(message_descriptor, dictionary)
+
+
+def InitMessage(message_descriptor, cls):
+  """Constructs a new message instance (called before instance's __init__)."""
+  cls._extensions_by_name = {}
+  _AddInitMethod(message_descriptor, cls)
+  _AddMessageMethods(message_descriptor, cls)
+  _AddPropertiesForExtensions(message_descriptor, cls)
+
+
+def _AddDescriptors(message_descriptor, dictionary):
+  """Sets up a new protocol message class dictionary.
+
+  Args:
+    message_descriptor: A Descriptor instance describing this message type.
+    dictionary: Class dictionary to which we'll add a '__slots__' entry.
+  """
+  dictionary['__descriptors'] = {}
+  for field in message_descriptor.fields:
+    dictionary['__descriptors'][field.name] = GetFieldDescriptor(
+        field.full_name)
+
+  dictionary['__slots__'] = list(dictionary['__descriptors'].iterkeys()) + [
+      '_cmsg', '_owner', '_composite_fields', 'Extensions']
+
+
+def _AddEnumValues(message_descriptor, dictionary):
+  """Sets class-level attributes for all enum fields defined in this message.
+
+  Args:
+    message_descriptor: Descriptor object for this message type.
+    dictionary: Class dictionary that should be populated.
+  """
+  for enum_type in message_descriptor.enum_types:
+    for enum_value in enum_type.values:
+      dictionary[enum_value.name] = enum_value.number
+
+
+def _AddClassAttributesForNestedExtensions(message_descriptor, dictionary):
+  """Adds class attributes for the nested extensions."""
+  extension_dict = message_descriptor.extensions_by_name
+  for extension_name, extension_field in extension_dict.iteritems():
+    assert extension_name not in dictionary
+    dictionary[extension_name] = extension_field
+
+
+def _AddInitMethod(message_descriptor, cls):
+  """Adds an __init__ method to cls."""
+
+  # Create and attach message field properties to the message class.
+  # This can be done just once per message class, since property setters and
+  # getters are passed the message instance.
+  # This makes message instantiation extremely fast, and at the same time it
+  # doesn't require the creation of property objects for each message instance,
+  # which saves a lot of memory.
+  for field in message_descriptor.fields:
+    field_cdescriptor = cls.__descriptors[field.name]
+    if field.label == _LABEL_REPEATED:
+      if field.cpp_type == _CPPTYPE_MESSAGE:
+        value = RepeatedCompositeProperty(field_cdescriptor, field.message_type)
+      else:
+        value = RepeatedScalarProperty(field_cdescriptor)
+    elif field.cpp_type == _CPPTYPE_MESSAGE:
+      value = CompositeProperty(field_cdescriptor, field.message_type)
+    else:
+      value = ScalarProperty(field_cdescriptor)
+    setattr(cls, field.name, value)
+
+    # Attach a constant with the field number.
+    constant_name = field.name.upper() + '_FIELD_NUMBER'
+    setattr(cls, constant_name, field.number)
+
+  def Init(self, **kwargs):
+    """Message constructor."""
+    cmessage = kwargs.pop('__cmessage', None)
+    if cmessage is None:
+      self._cmsg = NewCMessage(message_descriptor.full_name)
+    else:
+      self._cmsg = cmessage
+
+    # Keep a reference to the owner, as the owner keeps a reference to the
+    # underlying protocol buffer message.
+    owner = kwargs.pop('__owner', None)
+    if owner is not None:
+      self._owner = owner
+
+    self.Extensions = ExtensionDict(self)
+    self._composite_fields = {}
+
+    for field_name, field_value in kwargs.iteritems():
+      field_cdescriptor = self.__descriptors.get(field_name, None)
+      if field_cdescriptor is None:
+        raise ValueError('Protocol message has no "%s" field.' % field_name)
+      if field_cdescriptor.label == _LABEL_REPEATED:
+        if field_cdescriptor.cpp_type == _CPPTYPE_MESSAGE:
+          for val in field_value:
+            getattr(self, field_name).add().MergeFrom(val)
+        else:
+          getattr(self, field_name).extend(field_value)
+      elif field_cdescriptor.cpp_type == _CPPTYPE_MESSAGE:
+        getattr(self, field_name).MergeFrom(field_value)
+      else:
+        setattr(self, field_name, field_value)
+
+  Init.__module__ = None
+  Init.__doc__ = None
+  cls.__init__ = Init
+
+
+def _IsMessageSetExtension(field):
+  """Checks if a field is a message set extension."""
+  return (field.is_extension and
+          field.containing_type.has_options and
+          field.containing_type.GetOptions().message_set_wire_format and
+          field.type == _TYPE_MESSAGE and
+          field.message_type == field.extension_scope and
+          field.label == _LABEL_OPTIONAL)
+
+
+def _AddMessageMethods(message_descriptor, cls):
+  """Adds the methods to a protocol message class."""
+  if message_descriptor.is_extendable:
+
+    def ClearExtension(self, extension):
+      self.Extensions.ClearExtension(extension)
+
+    def HasExtension(self, extension):
+      return self.Extensions.HasExtension(extension)
+
+  def HasField(self, field_name):
+    return self._cmsg.HasField(field_name)
+
+  def ClearField(self, field_name):
+    if field_name in self._composite_fields:
+      del self._composite_fields[field_name]
+    self._cmsg.ClearField(field_name)
+
+  def Clear(self):
+    return self._cmsg.Clear()
+
+  def IsInitialized(self, errors=None):
+    if self._cmsg.IsInitialized():
+      return True
+    if errors is not None:
+      errors.extend(self.FindInitializationErrors());
+    return False
+
+  def SerializeToString(self):
+    if not self.IsInitialized():
+      raise message.EncodeError(
+          'Message is missing required fields: ' +
+          ','.join(self.FindInitializationErrors()))
+    return self._cmsg.SerializeToString()
+
+  def SerializePartialToString(self):
+    return self._cmsg.SerializePartialToString()
+
+  def ParseFromString(self, serialized):
+    self.Clear()
+    self.MergeFromString(serialized)
+
+  def MergeFromString(self, serialized):
+    byte_size = self._cmsg.MergeFromString(serialized)
+    if byte_size < 0:
+      raise message.DecodeError('Unable to merge from string.')
+    return byte_size
+
+  def MergeFrom(self, msg):
+    if not isinstance(msg, cls):
+      raise TypeError(
+          "Parameter to MergeFrom() must be instance of same class.")
+    self._cmsg.MergeFrom(msg._cmsg)
+
+  def CopyFrom(self, msg):
+    self._cmsg.CopyFrom(msg._cmsg)
+
+  def ByteSize(self):
+    return self._cmsg.ByteSize()
+
+  def SetInParent(self):
+    return self._cmsg.SetInParent()
+
+  def ListFields(self):
+    all_fields = []
+    field_list = self._cmsg.ListFields()
+    fields_by_name = cls.DESCRIPTOR.fields_by_name
+    for is_extension, field_name in field_list:
+      if is_extension:
+        extension = cls._extensions_by_name[field_name]
+        all_fields.append((extension, self.Extensions[extension]))
+      else:
+        field_descriptor = fields_by_name[field_name]
+        all_fields.append(
+            (field_descriptor, getattr(self, field_name)))
+    all_fields.sort(key=lambda item: item[0].number)
+    return all_fields
+
+  def FindInitializationErrors(self):
+    return self._cmsg.FindInitializationErrors()
+
+  def __str__(self):
+    return self._cmsg.DebugString()
+
+  def __eq__(self, other):
+    if self is other:
+      return True
+    if not isinstance(other, self.__class__):
+      return False
+    return self.ListFields() == other.ListFields()
+
+  def __ne__(self, other):
+    return not self == other
+
+  def __hash__(self):
+    raise TypeError('unhashable object')
+
+  def __unicode__(self):
+    return text_format.MessageToString(self, as_utf8=True).decode('utf-8')
+
+  # Attach the local methods to the message class.
+  for key, value in locals().copy().iteritems():
+    if key not in ('key', 'value', '__builtins__', '__name__', '__doc__'):
+      setattr(cls, key, value)
+
+  # Static methods:
+
+  def RegisterExtension(extension_handle):
+    extension_handle.containing_type = cls.DESCRIPTOR
+    cls._extensions_by_name[extension_handle.full_name] = extension_handle
+
+    if _IsMessageSetExtension(extension_handle):
+      # MessageSet extension.  Also register under type name.
+      cls._extensions_by_name[
+          extension_handle.message_type.full_name] = extension_handle
+  cls.RegisterExtension = staticmethod(RegisterExtension)
+
+  def FromString(string):
+    msg = cls()
+    msg.MergeFromString(string)
+    return msg
+  cls.FromString = staticmethod(FromString)
+
+
+
+def _AddPropertiesForExtensions(message_descriptor, cls):
+  """Adds properties for all fields in this protocol message type."""
+  extension_dict = message_descriptor.extensions_by_name
+  for extension_name, extension_field in extension_dict.iteritems():
+    constant_name = extension_name.upper() + '_FIELD_NUMBER'
+    setattr(cls, constant_name, extension_field.number)
diff --git a/python/google/protobuf/internal/decoder.py b/python/google/protobuf/internal/decoder.py
index 461a30c0..55f746f5 100755
--- a/python/google/protobuf/internal/decoder.py
+++ b/python/google/protobuf/internal/decoder.py
@@ -86,6 +86,13 @@ from google.protobuf.internal import wire_format
 from google.protobuf import message
 
 
+# This will overflow and thus become IEEE-754 "infinity".  We would use
+# "float('inf')" but it doesn't work on Windows pre-Python-2.6.
+_POS_INF = 1e10000
+_NEG_INF = -_POS_INF
+_NAN = _POS_INF * 0
+
+
 # This is not for optimization, but rather to avoid conflicts with local
 # variables named "message".
 _DecodeError = message.DecodeError
@@ -269,6 +276,72 @@ def _StructPackDecoder(wire_type, format):
   return _SimpleDecoder(wire_type, InnerDecode)
 
 
+def _FloatDecoder():
+  """Returns a decoder for a float field.
+
+  This code works around a bug in struct.unpack for non-finite 32-bit
+  floating-point values.
+  """
+
+  local_unpack = struct.unpack
+
+  def InnerDecode(buffer, pos):
+    # We expect a 32-bit value in little-endian byte order.  Bit 1 is the sign
+    # bit, bits 2-9 represent the exponent, and bits 10-32 are the significand.
+    new_pos = pos + 4
+    float_bytes = buffer[pos:new_pos]
+
+    # If this value has all its exponent bits set, then it's non-finite.
+    # In Python 2.4, struct.unpack will convert it to a finite 64-bit value.
+    # To avoid that, we parse it specially.
+    if ((float_bytes[3] in '\x7F\xFF')
+        and (float_bytes[2] >= '\x80')):
+      # If at least one significand bit is set...
+      if float_bytes[0:3] != '\x00\x00\x80':
+        return (_NAN, new_pos)
+      # If sign bit is set...
+      if float_bytes[3] == '\xFF':
+        return (_NEG_INF, new_pos)
+      return (_POS_INF, new_pos)
+
+    # Note that we expect someone up-stack to catch struct.error and convert
+    # it to _DecodeError -- this way we don't have to set up exception-
+    # handling blocks every time we parse one value.
+    result = local_unpack('<f', float_bytes)[0]
+    return (result, new_pos)
+  return _SimpleDecoder(wire_format.WIRETYPE_FIXED32, InnerDecode)
+
+
+def _DoubleDecoder():
+  """Returns a decoder for a double field.
+
+  This code works around a bug in struct.unpack for not-a-number.
+  """
+
+  local_unpack = struct.unpack
+
+  def InnerDecode(buffer, pos):
+    # We expect a 64-bit value in little-endian byte order.  Bit 1 is the sign
+    # bit, bits 2-12 represent the exponent, and bits 13-64 are the significand.
+    new_pos = pos + 8
+    double_bytes = buffer[pos:new_pos]
+
+    # If this value has all its exponent bits set and at least one significand
+    # bit set, it's not a number.  In Python 2.4, struct.unpack will treat it
+    # as inf or -inf.  To avoid that, we treat it specially.
+    if ((double_bytes[7] in '\x7F\xFF')
+        and (double_bytes[6] >= '\xF0')
+        and (double_bytes[0:7] != '\x00\x00\x00\x00\x00\x00\xF0')):
+      return (_NAN, new_pos)
+
+    # Note that we expect someone up-stack to catch struct.error and convert
+    # it to _DecodeError -- this way we don't have to set up exception-
+    # handling blocks every time we parse one value.
+    result = local_unpack('<d', double_bytes)[0]
+    return (result, new_pos)
+  return _SimpleDecoder(wire_format.WIRETYPE_FIXED64, InnerDecode)
+
+
 # --------------------------------------------------------------------
 
 
@@ -294,8 +367,8 @@ Fixed32Decoder  = _StructPackDecoder(wire_format.WIRETYPE_FIXED32, '<I')
 Fixed64Decoder  = _StructPackDecoder(wire_format.WIRETYPE_FIXED64, '<Q')
 SFixed32Decoder = _StructPackDecoder(wire_format.WIRETYPE_FIXED32, '<i')
 SFixed64Decoder = _StructPackDecoder(wire_format.WIRETYPE_FIXED64, '<q')
-FloatDecoder    = _StructPackDecoder(wire_format.WIRETYPE_FIXED32, '<f')
-DoubleDecoder   = _StructPackDecoder(wire_format.WIRETYPE_FIXED64, '<d')
+FloatDecoder = _FloatDecoder()
+DoubleDecoder = _DoubleDecoder()
 
 BoolDecoder = _ModifiedDecoder(
     wire_format.WIRETYPE_VARINT, _DecodeVarint, bool)
diff --git a/python/google/protobuf/internal/encoder.py b/python/google/protobuf/internal/encoder.py
index aa05d5b3..777975e8 100755
--- a/python/google/protobuf/internal/encoder.py
+++ b/python/google/protobuf/internal/encoder.py
@@ -70,6 +70,12 @@ import struct
 from google.protobuf.internal import wire_format
 
 
+# This will overflow and thus become IEEE-754 "infinity".  We would use
+# "float('inf')" but it doesn't work on Windows pre-Python-2.6.
+_POS_INF = 1e10000
+_NEG_INF = -_POS_INF
+
+
 def _VarintSize(value):
   """Compute the size of a varint value."""
   if value <= 0x7f: return 1
@@ -502,6 +508,83 @@ def _StructPackEncoder(wire_type, format):
   return SpecificEncoder
 
 
+def _FloatingPointEncoder(wire_type, format):
+  """Return a constructor for an encoder for float fields.
+
+  This is like StructPackEncoder, but catches errors that may be due to
+  passing non-finite floating-point values to struct.pack, and makes a
+  second attempt to encode those values.
+
+  Args:
+      wire_type:  The field's wire type, for encoding tags.
+      format:  The format string to pass to struct.pack().
+  """
+
+  value_size = struct.calcsize(format)
+  if value_size == 4:
+    def EncodeNonFiniteOrRaise(write, value):
+      # Remember that the serialized form uses little-endian byte order.
+      if value == _POS_INF:
+        write('\x00\x00\x80\x7F')
+      elif value == _NEG_INF:
+        write('\x00\x00\x80\xFF')
+      elif value != value:           # NaN
+        write('\x00\x00\xC0\x7F')
+      else:
+        raise
+  elif value_size == 8:
+    def EncodeNonFiniteOrRaise(write, value):
+      if value == _POS_INF:
+        write('\x00\x00\x00\x00\x00\x00\xF0\x7F')
+      elif value == _NEG_INF:
+        write('\x00\x00\x00\x00\x00\x00\xF0\xFF')
+      elif value != value:                         # NaN
+        write('\x00\x00\x00\x00\x00\x00\xF8\x7F')
+      else:
+        raise
+  else:
+    raise ValueError('Can\'t encode floating-point values that are '
+                     '%d bytes long (only 4 or 8)' % value_size)
+
+  def SpecificEncoder(field_number, is_repeated, is_packed):
+    local_struct_pack = struct.pack
+    if is_packed:
+      tag_bytes = TagBytes(field_number, wire_format.WIRETYPE_LENGTH_DELIMITED)
+      local_EncodeVarint = _EncodeVarint
+      def EncodePackedField(write, value):
+        write(tag_bytes)
+        local_EncodeVarint(write, len(value) * value_size)
+        for element in value:
+          # This try/except block is going to be faster than any code that
+          # we could write to check whether element is finite.
+          try:
+            write(local_struct_pack(format, element))
+          except SystemError:
+            EncodeNonFiniteOrRaise(write, element)
+      return EncodePackedField
+    elif is_repeated:
+      tag_bytes = TagBytes(field_number, wire_type)
+      def EncodeRepeatedField(write, value):
+        for element in value:
+          write(tag_bytes)
+          try:
+            write(local_struct_pack(format, element))
+          except SystemError:
+            EncodeNonFiniteOrRaise(write, element)
+      return EncodeRepeatedField
+    else:
+      tag_bytes = TagBytes(field_number, wire_type)
+      def EncodeField(write, value):
+        write(tag_bytes)
+        try:
+          write(local_struct_pack(format, value))
+        except SystemError:
+          EncodeNonFiniteOrRaise(write, value)
+      return EncodeField
+
+  return SpecificEncoder
+
+
 # ====================================================================
 # Here we declare an encoder constructor for each field type.  These work
 # very similarly to sizer constructors, described earlier.
@@ -525,8 +608,8 @@ Fixed32Encoder  = _StructPackEncoder(wire_format.WIRETYPE_FIXED32, '<I')
 Fixed64Encoder  = _StructPackEncoder(wire_format.WIRETYPE_FIXED64, '<Q')
 SFixed32Encoder = _StructPackEncoder(wire_format.WIRETYPE_FIXED32, '<i')
 SFixed64Encoder = _StructPackEncoder(wire_format.WIRETYPE_FIXED64, '<q')
-FloatEncoder    = _StructPackEncoder(wire_format.WIRETYPE_FIXED32, '<f')
-DoubleEncoder   = _StructPackEncoder(wire_format.WIRETYPE_FIXED64, '<d')
+FloatEncoder    = _FloatingPointEncoder(wire_format.WIRETYPE_FIXED32, '<f')
+DoubleEncoder   = _FloatingPointEncoder(wire_format.WIRETYPE_FIXED64, '<d')
 
 
 def BoolEncoder(field_number, is_repeated, is_packed):
diff --git a/python/google/protobuf/internal/generator_test.py b/python/google/protobuf/internal/generator_test.py
index 78360b53..e4387c85 100755
--- a/python/google/protobuf/internal/generator_test.py
+++ b/python/google/protobuf/internal/generator_test.py
@@ -42,11 +42,12 @@ further ensures that we can use Python protocol message objects as we expect.
 __author__ = 'robinson@google.com (Will Robinson)'
 
 import unittest
+from google.protobuf import unittest_custom_options_pb2
 from google.protobuf import unittest_import_pb2
 from google.protobuf import unittest_mset_pb2
 from google.protobuf import unittest_pb2
 from google.protobuf import unittest_no_generic_services_pb2
-
+from google.protobuf import service
 
 MAX_EXTENSION = 536870912
 
@@ -140,6 +141,13 @@ class GeneratorTest(unittest.TestCase):
     proto = unittest_mset_pb2.TestMessageSet()
     self.assertTrue(proto.DESCRIPTOR.GetOptions().message_set_wire_format)
 
+  def testMessageWithCustomOptions(self):
+    proto = unittest_custom_options_pb2.TestMessageWithCustomOptions()
+    enum_options = proto.DESCRIPTOR.enum_types_by_name['AnEnum'].GetOptions()
+    self.assertTrue(enum_options is not None)
+    # TODO(gps): We really should test for the presense of the enum_opt1
+    # extension and for its value to be set to -789.
+
   def testNestedTypes(self):
     self.assertEquals(
         set(unittest_pb2.TestAllTypes.DESCRIPTOR.nested_types),
@@ -208,12 +216,27 @@ class GeneratorTest(unittest.TestCase):
     self.assertFalse(unittest_pb2.DESCRIPTOR.serialized_pb is None)
 
   def testNoGenericServices(self):
-    # unittest_no_generic_services.proto should contain defs for everything
-    # except services.
     self.assertTrue(hasattr(unittest_no_generic_services_pb2, "TestMessage"))
     self.assertTrue(hasattr(unittest_no_generic_services_pb2, "FOO"))
     self.assertTrue(hasattr(unittest_no_generic_services_pb2, "test_extension"))
-    self.assertFalse(hasattr(unittest_no_generic_services_pb2, "TestService"))
+
+    # Make sure unittest_no_generic_services_pb2 has no services subclassing
+    # Proto2 Service class.
+    if hasattr(unittest_no_generic_services_pb2, "TestService"):
+      self.assertFalse(issubclass(unittest_no_generic_services_pb2.TestService,
+                                  service.Service))
+
+  def testMessageTypesByName(self):
+    file_type = unittest_pb2.DESCRIPTOR
+    self.assertEqual(
+        unittest_pb2._TESTALLTYPES,
+        file_type.message_types_by_name[unittest_pb2._TESTALLTYPES.name])
+
+    # Nested messages shouldn't be included in the message_types_by_name
+    # dictionary (like in the C++ API).
+    self.assertFalse(
+        unittest_pb2._TESTALLTYPES_NESTEDMESSAGE.name in
+        file_type.message_types_by_name)
 
 
 if __name__ == '__main__':
diff --git a/python/google/protobuf/internal/message_test.py b/python/google/protobuf/internal/message_test.py
index 73a9a3a3..65174373 100755
--- a/python/google/protobuf/internal/message_test.py
+++ b/python/google/protobuf/internal/message_test.py
@@ -43,11 +43,25 @@ abstract interface.
 
 __author__ = 'gps@google.com (Gregory P. Smith)'
 
+import copy
+import math
 import unittest
 from google.protobuf import unittest_import_pb2
 from google.protobuf import unittest_pb2
 from google.protobuf.internal import test_util
 
+# Python pre-2.6 does not have isinf() or isnan() functions, so we have
+# to provide our own.
+def isnan(val):
+  # NaN is never equal to itself.
+  return val != val
+def isinf(val):
+  # Infinity times zero equals NaN.
+  return not isnan(val) and isnan(val * 0)
+def IsPosInf(val):
+  return isinf(val) and (val > 0)
+def IsNegInf(val):
+  return isinf(val) and (val < 0)
 
 class MessageTest(unittest.TestCase):
 
@@ -57,6 +71,8 @@ class MessageTest(unittest.TestCase):
     golden_message.ParseFromString(golden_data)
     test_util.ExpectAllFieldsSet(self, golden_message)
     self.assertTrue(golden_message.SerializeToString() == golden_data)
+    golden_copy = copy.deepcopy(golden_message)
+    self.assertTrue(golden_copy.SerializeToString() == golden_data)
 
   def testGoldenExtensions(self):
     golden_data = test_util.GoldenFile('golden_message').read()
@@ -66,6 +82,8 @@ class MessageTest(unittest.TestCase):
     test_util.SetAllExtensions(all_set)
     self.assertEquals(all_set, golden_message)
     self.assertTrue(golden_message.SerializeToString() == golden_data)
+    golden_copy = copy.deepcopy(golden_message)
+    self.assertTrue(golden_copy.SerializeToString() == golden_data)
 
   def testGoldenPackedMessage(self):
     golden_data = test_util.GoldenFile('golden_packed_fields_message').read()
@@ -75,6 +93,8 @@ class MessageTest(unittest.TestCase):
     test_util.SetAllPackedFields(all_set)
     self.assertEquals(all_set, golden_message)
     self.assertTrue(all_set.SerializeToString() == golden_data)
+    golden_copy = copy.deepcopy(golden_message)
+    self.assertTrue(golden_copy.SerializeToString() == golden_data)
 
   def testGoldenPackedExtensions(self):
     golden_data = test_util.GoldenFile('golden_packed_fields_message').read()
@@ -84,6 +104,240 @@ class MessageTest(unittest.TestCase):
     test_util.SetAllPackedExtensions(all_set)
     self.assertEquals(all_set, golden_message)
     self.assertTrue(all_set.SerializeToString() == golden_data)
+    golden_copy = copy.deepcopy(golden_message)
+    self.assertTrue(golden_copy.SerializeToString() == golden_data)
+
+  def testPositiveInfinity(self):
+    golden_data = ('\x5D\x00\x00\x80\x7F'
+                   '\x61\x00\x00\x00\x00\x00\x00\xF0\x7F'
+                   '\xCD\x02\x00\x00\x80\x7F'
+                   '\xD1\x02\x00\x00\x00\x00\x00\x00\xF0\x7F')
+    golden_message = unittest_pb2.TestAllTypes()
+    golden_message.ParseFromString(golden_data)
+    self.assertTrue(IsPosInf(golden_message.optional_float))
+    self.assertTrue(IsPosInf(golden_message.optional_double))
+    self.assertTrue(IsPosInf(golden_message.repeated_float[0]))
+    self.assertTrue(IsPosInf(golden_message.repeated_double[0]))
+    self.assertTrue(golden_message.SerializeToString() == golden_data)
+
+  def testNegativeInfinity(self):
+    golden_data = ('\x5D\x00\x00\x80\xFF'
+                   '\x61\x00\x00\x00\x00\x00\x00\xF0\xFF'
+                   '\xCD\x02\x00\x00\x80\xFF'
+                   '\xD1\x02\x00\x00\x00\x00\x00\x00\xF0\xFF')
+    golden_message = unittest_pb2.TestAllTypes()
+    golden_message.ParseFromString(golden_data)
+    self.assertTrue(IsNegInf(golden_message.optional_float))
+    self.assertTrue(IsNegInf(golden_message.optional_double))
+    self.assertTrue(IsNegInf(golden_message.repeated_float[0]))
+    self.assertTrue(IsNegInf(golden_message.repeated_double[0]))
+    self.assertTrue(golden_message.SerializeToString() == golden_data)
+
+  def testNotANumber(self):
+    golden_data = ('\x5D\x00\x00\xC0\x7F'
+                   '\x61\x00\x00\x00\x00\x00\x00\xF8\x7F'
+                   '\xCD\x02\x00\x00\xC0\x7F'
+                   '\xD1\x02\x00\x00\x00\x00\x00\x00\xF8\x7F')
+    golden_message = unittest_pb2.TestAllTypes()
+    golden_message.ParseFromString(golden_data)
+    self.assertTrue(isnan(golden_message.optional_float))
+    self.assertTrue(isnan(golden_message.optional_double))
+    self.assertTrue(isnan(golden_message.repeated_float[0]))
+    self.assertTrue(isnan(golden_message.repeated_double[0]))
+    self.assertTrue(golden_message.SerializeToString() == golden_data)
+
+  def testPositiveInfinityPacked(self):
+    golden_data = ('\xA2\x06\x04\x00\x00\x80\x7F'
+                   '\xAA\x06\x08\x00\x00\x00\x00\x00\x00\xF0\x7F')
+    golden_message = unittest_pb2.TestPackedTypes()
+    golden_message.ParseFromString(golden_data)
+    self.assertTrue(IsPosInf(golden_message.packed_float[0]))
+    self.assertTrue(IsPosInf(golden_message.packed_double[0]))
+    self.assertTrue(golden_message.SerializeToString() == golden_data)
+
+  def testNegativeInfinityPacked(self):
+    golden_data = ('\xA2\x06\x04\x00\x00\x80\xFF'
+                   '\xAA\x06\x08\x00\x00\x00\x00\x00\x00\xF0\xFF')
+    golden_message = unittest_pb2.TestPackedTypes()
+    golden_message.ParseFromString(golden_data)
+    self.assertTrue(IsNegInf(golden_message.packed_float[0]))
+    self.assertTrue(IsNegInf(golden_message.packed_double[0]))
+    self.assertTrue(golden_message.SerializeToString() == golden_data)
+
+  def testNotANumberPacked(self):
+    golden_data = ('\xA2\x06\x04\x00\x00\xC0\x7F'
+                   '\xAA\x06\x08\x00\x00\x00\x00\x00\x00\xF8\x7F')
+    golden_message = unittest_pb2.TestPackedTypes()
+    golden_message.ParseFromString(golden_data)
+    self.assertTrue(isnan(golden_message.packed_float[0]))
+    self.assertTrue(isnan(golden_message.packed_double[0]))
+    self.assertTrue(golden_message.SerializeToString() == golden_data)
+
+  def testExtremeFloatValues(self):
+    message = unittest_pb2.TestAllTypes()
+
+    # Most positive exponent, no significand bits set.
+    kMostPosExponentNoSigBits = math.pow(2, 127)
+    message.optional_float = kMostPosExponentNoSigBits
+    message.ParseFromString(message.SerializeToString())
+    self.assertTrue(message.optional_float == kMostPosExponentNoSigBits)
+
+    # Most positive exponent, one significand bit set.
+    kMostPosExponentOneSigBit = 1.5 * math.pow(2, 127)
+    message.optional_float = kMostPosExponentOneSigBit
+    message.ParseFromString(message.SerializeToString())
+    self.assertTrue(message.optional_float == kMostPosExponentOneSigBit)
+
+    # Repeat last two cases with values of same magnitude, but negative.
+    message.optional_float = -kMostPosExponentNoSigBits
+    message.ParseFromString(message.SerializeToString())
+    self.assertTrue(message.optional_float == -kMostPosExponentNoSigBits)
+
+    message.optional_float = -kMostPosExponentOneSigBit
+    message.ParseFromString(message.SerializeToString())
+    self.assertTrue(message.optional_float == -kMostPosExponentOneSigBit)
+
+    # Most negative exponent, no significand bits set.
+    kMostNegExponentNoSigBits = math.pow(2, -127)
+    message.optional_float = kMostNegExponentNoSigBits
+    message.ParseFromString(message.SerializeToString())
+    self.assertTrue(message.optional_float == kMostNegExponentNoSigBits)
+
+    # Most negative exponent, one significand bit set.
+    kMostNegExponentOneSigBit = 1.5 * math.pow(2, -127)
+    message.optional_float = kMostNegExponentOneSigBit
+    message.ParseFromString(message.SerializeToString())
+    self.assertTrue(message.optional_float == kMostNegExponentOneSigBit)
+
+    # Repeat last two cases with values of the same magnitude, but negative.
+    message.optional_float = -kMostNegExponentNoSigBits
+    message.ParseFromString(message.SerializeToString())
+    self.assertTrue(message.optional_float == -kMostNegExponentNoSigBits)
+
+    message.optional_float = -kMostNegExponentOneSigBit
+    message.ParseFromString(message.SerializeToString())
+    self.assertTrue(message.optional_float == -kMostNegExponentOneSigBit)
+
+  def testExtremeFloatValues(self):
+    message = unittest_pb2.TestAllTypes()
+
+    # Most positive exponent, no significand bits set.
+    kMostPosExponentNoSigBits = math.pow(2, 1023)
+    message.optional_double = kMostPosExponentNoSigBits
+    message.ParseFromString(message.SerializeToString())
+    self.assertTrue(message.optional_double == kMostPosExponentNoSigBits)
+
+    # Most positive exponent, one significand bit set.
+    kMostPosExponentOneSigBit = 1.5 * math.pow(2, 1023)
+    message.optional_double = kMostPosExponentOneSigBit
+    message.ParseFromString(message.SerializeToString())
+    self.assertTrue(message.optional_double == kMostPosExponentOneSigBit)
+
+    # Repeat last two cases with values of same magnitude, but negative.
+    message.optional_double = -kMostPosExponentNoSigBits
+    message.ParseFromString(message.SerializeToString())
+    self.assertTrue(message.optional_double == -kMostPosExponentNoSigBits)
+
+    message.optional_double = -kMostPosExponentOneSigBit
+    message.ParseFromString(message.SerializeToString())
+    self.assertTrue(message.optional_double == -kMostPosExponentOneSigBit)
+
+    # Most negative exponent, no significand bits set.
+    kMostNegExponentNoSigBits = math.pow(2, -1023)
+    message.optional_double = kMostNegExponentNoSigBits
+    message.ParseFromString(message.SerializeToString())
+    self.assertTrue(message.optional_double == kMostNegExponentNoSigBits)
+
+    # Most negative exponent, one significand bit set.
+    kMostNegExponentOneSigBit = 1.5 * math.pow(2, -1023)
+    message.optional_double = kMostNegExponentOneSigBit
+    message.ParseFromString(message.SerializeToString())
+    self.assertTrue(message.optional_double == kMostNegExponentOneSigBit)
+
+    # Repeat last two cases with values of the same magnitude, but negative.
+    message.optional_double = -kMostNegExponentNoSigBits
+    message.ParseFromString(message.SerializeToString())
+    self.assertTrue(message.optional_double == -kMostNegExponentNoSigBits)
+
+    message.optional_double = -kMostNegExponentOneSigBit
+    message.ParseFromString(message.SerializeToString())
+    self.assertTrue(message.optional_double == -kMostNegExponentOneSigBit)
+
+  def testSortingRepeatedScalarFieldsDefaultComparator(self):
+    """Check some different types with the default comparator."""
+    message = unittest_pb2.TestAllTypes()
+
+    # TODO(mattp): would testing more scalar types strengthen test?
+    message.repeated_int32.append(1)
+    message.repeated_int32.append(3)
+    message.repeated_int32.append(2)
+    message.repeated_int32.sort()
+    self.assertEqual(message.repeated_int32[0], 1)
+    self.assertEqual(message.repeated_int32[1], 2)
+    self.assertEqual(message.repeated_int32[2], 3)
+
+    message.repeated_float.append(1.1)
+    message.repeated_float.append(1.3)
+    message.repeated_float.append(1.2)
+    message.repeated_float.sort()
+    self.assertAlmostEqual(message.repeated_float[0], 1.1)
+    self.assertAlmostEqual(message.repeated_float[1], 1.2)
+    self.assertAlmostEqual(message.repeated_float[2], 1.3)
+
+    message.repeated_string.append('a')
+    message.repeated_string.append('c')
+    message.repeated_string.append('b')
+    message.repeated_string.sort()
+    self.assertEqual(message.repeated_string[0], 'a')
+    self.assertEqual(message.repeated_string[1], 'b')
+    self.assertEqual(message.repeated_string[2], 'c')
+
+    message.repeated_bytes.append('a')
+    message.repeated_bytes.append('c')
+    message.repeated_bytes.append('b')
+    message.repeated_bytes.sort()
+    self.assertEqual(message.repeated_bytes[0], 'a')
+    self.assertEqual(message.repeated_bytes[1], 'b')
+    self.assertEqual(message.repeated_bytes[2], 'c')
+
+  def testSortingRepeatedScalarFieldsCustomComparator(self):
+    """Check some different types with custom comparator."""
+    message = unittest_pb2.TestAllTypes()
+
+    message.repeated_int32.append(-3)
+    message.repeated_int32.append(-2)
+    message.repeated_int32.append(-1)
+    message.repeated_int32.sort(lambda x,y: cmp(abs(x), abs(y)))
+    self.assertEqual(message.repeated_int32[0], -1)
+    self.assertEqual(message.repeated_int32[1], -2)
+    self.assertEqual(message.repeated_int32[2], -3)
+
+    message.repeated_string.append('aaa')
+    message.repeated_string.append('bb')
+    message.repeated_string.append('c')
+    message.repeated_string.sort(lambda x,y: cmp(len(x), len(y)))
+    self.assertEqual(message.repeated_string[0], 'c')
+    self.assertEqual(message.repeated_string[1], 'bb')
+    self.assertEqual(message.repeated_string[2], 'aaa')
+
+  def testSortingRepeatedCompositeFieldsCustomComparator(self):
+    """Check passing a custom comparator to sort a repeated composite field."""
+    message = unittest_pb2.TestAllTypes()
+
+    message.repeated_nested_message.add().bb = 1
+    message.repeated_nested_message.add().bb = 3
+    message.repeated_nested_message.add().bb = 2
+    message.repeated_nested_message.add().bb = 6
+    message.repeated_nested_message.add().bb = 5
+    message.repeated_nested_message.add().bb = 4
+    message.repeated_nested_message.sort(lambda x,y: cmp(x.bb, y.bb))
+    self.assertEqual(message.repeated_nested_message[0].bb, 1)
+    self.assertEqual(message.repeated_nested_message[1].bb, 2)
+    self.assertEqual(message.repeated_nested_message[2].bb, 3)
+    self.assertEqual(message.repeated_nested_message[3].bb, 4)
+    self.assertEqual(message.repeated_nested_message[4].bb, 5)
+    self.assertEqual(message.repeated_nested_message[5].bb, 6)
+
 
 if __name__ == '__main__':
   unittest.main()
diff --git a/python/google/protobuf/internal/python_message.py b/python/google/protobuf/internal/python_message.py
new file mode 100755
index 00000000..66fca918
--- /dev/null
+++ b/python/google/protobuf/internal/python_message.py
@@ -0,0 +1,1098 @@
+# Protocol Buffers - Google's data interchange format
+# Copyright 2008 Google Inc.  All rights reserved.
+# http://code.google.com/p/protobuf/
+#
+# 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.
+
+# This code is meant to work on Python 2.4 and above only.
+#
+# TODO(robinson): Helpers for verbose, common checks like seeing if a
+# descriptor's cpp_type is CPPTYPE_MESSAGE.
+
+"""Contains a metaclass and helper functions used to create
+protocol message classes from Descriptor objects at runtime.
+
+Recall that a metaclass is the "type" of a class.
+(A class is to a metaclass what an instance is to a class.)
+
+In this case, we use the GeneratedProtocolMessageType metaclass
+to inject all the useful functionality into the classes
+output by the protocol compiler at compile-time.
+
+The upshot of all this is that the real implementation
+details for ALL pure-Python protocol buffers are *here in
+this file*.
+"""
+
+__author__ = 'robinson@google.com (Will Robinson)'
+
+try:
+  from cStringIO import StringIO
+except ImportError:
+  from StringIO import StringIO
+import struct
+import weakref
+
+# We use "as" to avoid name collisions with variables.
+from google.protobuf.internal import containers
+from google.protobuf.internal import decoder
+from google.protobuf.internal import encoder
+from google.protobuf.internal import message_listener as message_listener_mod
+from google.protobuf.internal import type_checkers
+from google.protobuf.internal import wire_format
+from google.protobuf import descriptor as descriptor_mod
+from google.protobuf import message as message_mod
+from google.protobuf import text_format
+
+_FieldDescriptor = descriptor_mod.FieldDescriptor
+
+
+def NewMessage(descriptor, dictionary):
+  _AddClassAttributesForNestedExtensions(descriptor, dictionary)
+  _AddSlots(descriptor, dictionary)
+
+
+def InitMessage(descriptor, cls):
+  cls._decoders_by_tag = {}
+  cls._extensions_by_name = {}
+  cls._extensions_by_number = {}
+  if (descriptor.has_options and
+      descriptor.GetOptions().message_set_wire_format):
+    cls._decoders_by_tag[decoder.MESSAGE_SET_ITEM_TAG] = (
+        decoder.MessageSetItemDecoder(cls._extensions_by_number))
+
+  # Attach stuff to each FieldDescriptor for quick lookup later on.
+  for field in descriptor.fields:
+    _AttachFieldHelpers(cls, field)
+
+  _AddEnumValues(descriptor, cls)
+  _AddInitMethod(descriptor, cls)
+  _AddPropertiesForFields(descriptor, cls)
+  _AddPropertiesForExtensions(descriptor, cls)
+  _AddStaticMethods(cls)
+  _AddMessageMethods(descriptor, cls)
+  _AddPrivateHelperMethods(cls)
+
+
+# Stateless helpers for GeneratedProtocolMessageType below.
+# Outside clients should not access these directly.
+#
+# I opted not to make any of these methods on the metaclass, to make it more
+# clear that I'm not really using any state there and to keep clients from
+# thinking that they have direct access to these construction helpers.
+
+
+def _PropertyName(proto_field_name):
+  """Returns the name of the public property attribute which
+  clients can use to get and (in some cases) set the value
+  of a protocol message field.
+
+  Args:
+    proto_field_name: The protocol message field name, exactly
+      as it appears (or would appear) in a .proto file.
+  """
+  # TODO(robinson): Escape Python keywords (e.g., yield), and test this support.
+  # nnorwitz makes my day by writing:
+  # """
+  # FYI.  See the keyword module in the stdlib. This could be as simple as:
+  #
+  # if keyword.iskeyword(proto_field_name):
+  #   return proto_field_name + "_"
+  # return proto_field_name
+  # """
+  # Kenton says:  The above is a BAD IDEA.  People rely on being able to use
+  #   getattr() and setattr() to reflectively manipulate field values.  If we
+  #   rename the properties, then every such user has to also make sure to apply
+  #   the same transformation.  Note that currently if you name a field "yield",
+  #   you can still access it just fine using getattr/setattr -- it's not even
+  #   that cumbersome to do so.
+  # TODO(kenton):  Remove this method entirely if/when everyone agrees with my
+  #   position.
+  return proto_field_name
+
+
+def _VerifyExtensionHandle(message, extension_handle):
+  """Verify that the given extension handle is valid."""
+
+  if not isinstance(extension_handle, _FieldDescriptor):
+    raise KeyError('HasExtension() expects an extension handle, got: %s' %
+                   extension_handle)
+
+  if not extension_handle.is_extension:
+    raise KeyError('"%s" is not an extension.' % extension_handle.full_name)
+
+  if extension_handle.containing_type is not message.DESCRIPTOR:
+    raise KeyError('Extension "%s" extends message type "%s", but this '
+                   'message is of type "%s".' %
+                   (extension_handle.full_name,
+                    extension_handle.containing_type.full_name,
+                    message.DESCRIPTOR.full_name))
+
+
+def _AddSlots(message_descriptor, dictionary):
+  """Adds a __slots__ entry to dictionary, containing the names of all valid
+  attributes for this message type.
+
+  Args:
+    message_descriptor: A Descriptor instance describing this message type.
+    dictionary: Class dictionary to which we'll add a '__slots__' entry.
+  """
+  dictionary['__slots__'] = ['_cached_byte_size',
+                             '_cached_byte_size_dirty',
+                             '_fields',
+                             '_is_present_in_parent',
+                             '_listener',
+                             '_listener_for_children',
+                             '__weakref__']
+
+
+def _IsMessageSetExtension(field):
+  return (field.is_extension and
+          field.containing_type.has_options and
+          field.containing_type.GetOptions().message_set_wire_format and
+          field.type == _FieldDescriptor.TYPE_MESSAGE and
+          field.message_type == field.extension_scope and
+          field.label == _FieldDescriptor.LABEL_OPTIONAL)
+
+
+def _AttachFieldHelpers(cls, field_descriptor):
+  is_repeated = (field_descriptor.label == _FieldDescriptor.LABEL_REPEATED)
+  is_packed = (field_descriptor.has_options and
+               field_descriptor.GetOptions().packed)
+
+  if _IsMessageSetExtension(field_descriptor):
+    field_encoder = encoder.MessageSetItemEncoder(field_descriptor.number)
+    sizer = encoder.MessageSetItemSizer(field_descriptor.number)
+  else:
+    field_encoder = type_checkers.TYPE_TO_ENCODER[field_descriptor.type](
+        field_descriptor.number, is_repeated, is_packed)
+    sizer = type_checkers.TYPE_TO_SIZER[field_descriptor.type](
+        field_descriptor.number, is_repeated, is_packed)
+
+  field_descriptor._encoder = field_encoder
+  field_descriptor._sizer = sizer
+  field_descriptor._default_constructor = _DefaultValueConstructorForField(
+      field_descriptor)
+
+  def AddDecoder(wiretype, is_packed):
+    tag_bytes = encoder.TagBytes(field_descriptor.number, wiretype)
+    cls._decoders_by_tag[tag_bytes] = (
+        type_checkers.TYPE_TO_DECODER[field_descriptor.type](
+            field_descriptor.number, is_repeated, is_packed,
+            field_descriptor, field_descriptor._default_constructor))
+
+  AddDecoder(type_checkers.FIELD_TYPE_TO_WIRE_TYPE[field_descriptor.type],
+             False)
+
+  if is_repeated and wire_format.IsTypePackable(field_descriptor.type):
+    # To support wire compatibility of adding packed = true, add a decoder for
+    # packed values regardless of the field's options.
+    AddDecoder(wire_format.WIRETYPE_LENGTH_DELIMITED, True)
+
+
+def _AddClassAttributesForNestedExtensions(descriptor, dictionary):
+  extension_dict = descriptor.extensions_by_name
+  for extension_name, extension_field in extension_dict.iteritems():
+    assert extension_name not in dictionary
+    dictionary[extension_name] = extension_field
+
+
+def _AddEnumValues(descriptor, cls):
+  """Sets class-level attributes for all enum fields defined in this message.
+
+  Args:
+    descriptor: Descriptor object for this message type.
+    cls: Class we're constructing for this message type.
+  """
+  for enum_type in descriptor.enum_types:
+    for enum_value in enum_type.values:
+      setattr(cls, enum_value.name, enum_value.number)
+
+
+def _DefaultValueConstructorForField(field):
+  """Returns a function which returns a default value for a field.
+
+  Args:
+    field: FieldDescriptor object for this field.
+
+  The returned function has one argument:
+    message: Message instance containing this field, or a weakref proxy
+      of same.
+
+  That function in turn returns a default value for this field.  The default
+    value may refer back to |message| via a weak reference.
+  """
+
+  if field.label == _FieldDescriptor.LABEL_REPEATED:
+    if field.default_value != []:
+      raise ValueError('Repeated field default value not empty list: %s' % (
+          field.default_value))
+    if field.cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE:
+      # We can't look at _concrete_class yet since it might not have
+      # been set.  (Depends on order in which we initialize the classes).
+      message_type = field.message_type
+      def MakeRepeatedMessageDefault(message):
+        return containers.RepeatedCompositeFieldContainer(
+            message._listener_for_children, field.message_type)
+      return MakeRepeatedMessageDefault
+    else:
+      type_checker = type_checkers.GetTypeChecker(field.cpp_type, field.type)
+      def MakeRepeatedScalarDefault(message):
+        return containers.RepeatedScalarFieldContainer(
+            message._listener_for_children, type_checker)
+      return MakeRepeatedScalarDefault
+
+  if field.cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE:
+    # _concrete_class may not yet be initialized.
+    message_type = field.message_type
+    def MakeSubMessageDefault(message):
+      result = message_type._concrete_class()
+      result._SetListener(message._listener_for_children)
+      return result
+    return MakeSubMessageDefault
+
+  def MakeScalarDefault(message):
+    return field.default_value
+  return MakeScalarDefault
+
+
+def _AddInitMethod(message_descriptor, cls):
+  """Adds an __init__ method to cls."""
+  fields = message_descriptor.fields
+  def init(self, **kwargs):
+    self._cached_byte_size = 0
+    self._cached_byte_size_dirty = len(kwargs) > 0
+    self._fields = {}
+    self._is_present_in_parent = False
+    self._listener = message_listener_mod.NullMessageListener()
+    self._listener_for_children = _Listener(self)
+    for field_name, field_value in kwargs.iteritems():
+      field = _GetFieldByName(message_descriptor, field_name)
+      if field is None:
+        raise TypeError("%s() got an unexpected keyword argument '%s'" %
+                        (message_descriptor.name, field_name))
+      if field.label == _FieldDescriptor.LABEL_REPEATED:
+        copy = field._default_constructor(self)
+        if field.cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE:  # Composite
+          for val in field_value:
+            copy.add().MergeFrom(val)
+        else:  # Scalar
+          copy.extend(field_value)
+        self._fields[field] = copy
+      elif field.cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE:
+        copy = field._default_constructor(self)
+        copy.MergeFrom(field_value)
+        self._fields[field] = copy
+      else:
+        setattr(self, field_name, field_value)
+
+  init.__module__ = None
+  init.__doc__ = None
+  cls.__init__ = init
+
+
+def _GetFieldByName(message_descriptor, field_name):
+  """Returns a field descriptor by field name.
+
+  Args:
+    message_descriptor: A Descriptor describing all fields in message.
+    field_name: The name of the field to retrieve.
+  Returns:
+    The field descriptor associated with the field name.
+  """
+  try:
+    return message_descriptor.fields_by_name[field_name]
+  except KeyError:
+    raise ValueError('Protocol message has no "%s" field.' % field_name)
+
+
+def _AddPropertiesForFields(descriptor, cls):
+  """Adds properties for all fields in this protocol message type."""
+  for field in descriptor.fields:
+    _AddPropertiesForField(field, cls)
+
+  if descriptor.is_extendable:
+    # _ExtensionDict is just an adaptor with no state so we allocate a new one
+    # every time it is accessed.
+    cls.Extensions = property(lambda self: _ExtensionDict(self))
+
+
+def _AddPropertiesForField(field, cls):
+  """Adds a public property for a protocol message field.
+  Clients can use this property to get and (in the case
+  of non-repeated scalar fields) directly set the value
+  of a protocol message field.
+
+  Args:
+    field: A FieldDescriptor for this field.
+    cls: The class we're constructing.
+  """
+  # Catch it if we add other types that we should
+  # handle specially here.
+  assert _FieldDescriptor.MAX_CPPTYPE == 10
+
+  constant_name = field.name.upper() + "_FIELD_NUMBER"
+  setattr(cls, constant_name, field.number)
+
+  if field.label == _FieldDescriptor.LABEL_REPEATED:
+    _AddPropertiesForRepeatedField(field, cls)
+  elif field.cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE:
+    _AddPropertiesForNonRepeatedCompositeField(field, cls)
+  else:
+    _AddPropertiesForNonRepeatedScalarField(field, cls)
+
+
+def _AddPropertiesForRepeatedField(field, cls):
+  """Adds a public property for a "repeated" protocol message field.  Clients
+  can use this property to get the value of the field, which will be either a
+  _RepeatedScalarFieldContainer or _RepeatedCompositeFieldContainer (see
+  below).
+
+  Note that when clients add values to these containers, we perform
+  type-checking in the case of repeated scalar fields, and we also set any
+  necessary "has" bits as a side-effect.
+
+  Args:
+    field: A FieldDescriptor for this field.
+    cls: The class we're constructing.
+  """
+  proto_field_name = field.name
+  property_name = _PropertyName(proto_field_name)
+
+  def getter(self):
+    field_value = self._fields.get(field)
+    if field_value is None:
+      # Construct a new object to represent this field.
+      field_value = field._default_constructor(self)
+
+      # Atomically check if another thread has preempted us and, if not, swap
+      # in the new object we just created.  If someone has preempted us, we
+      # take that object and discard ours.
+      # WARNING:  We are relying on setdefault() being atomic.  This is true
+      #   in CPython but we haven't investigated others.  This warning appears
+      #   in several other locations in this file.
+      field_value = self._fields.setdefault(field, field_value)
+    return field_value
+  getter.__module__ = None
+  getter.__doc__ = 'Getter for %s.' % proto_field_name
+
+  # We define a setter just so we can throw an exception with a more
+  # helpful error message.
+  def setter(self, new_value):
+    raise AttributeError('Assignment not allowed to repeated field '
+                         '"%s" in protocol message object.' % proto_field_name)
+
+  doc = 'Magic attribute generated for "%s" proto field.' % proto_field_name
+  setattr(cls, property_name, property(getter, setter, doc=doc))
+
+
+def _AddPropertiesForNonRepeatedScalarField(field, cls):
+  """Adds a public property for a nonrepeated, scalar protocol message field.
+  Clients can use this property to get and directly set the value of the field.
+  Note that when the client sets the value of a field by using this property,
+  all necessary "has" bits are set as a side-effect, and we also perform
+  type-checking.
+
+  Args:
+    field: A FieldDescriptor for this field.
+    cls: The class we're constructing.
+  """
+  proto_field_name = field.name
+  property_name = _PropertyName(proto_field_name)
+  type_checker = type_checkers.GetTypeChecker(field.cpp_type, field.type)
+  default_value = field.default_value
+  valid_values = set()
+
+  def getter(self):
+    return self._fields.get(field, default_value)
+  getter.__module__ = None
+  getter.__doc__ = 'Getter for %s.' % proto_field_name
+  def setter(self, new_value):
+    type_checker.CheckValue(new_value)
+    self._fields[field] = new_value
+    # Check _cached_byte_size_dirty inline to improve performance, since scalar
+    # setters are called frequently.
+    if not self._cached_byte_size_dirty:
+      self._Modified()
+
+  setter.__module__ = None
+  setter.__doc__ = 'Setter for %s.' % proto_field_name
+
+  # Add a property to encapsulate the getter/setter.
+  doc = 'Magic attribute generated for "%s" proto field.' % proto_field_name
+  setattr(cls, property_name, property(getter, setter, doc=doc))
+
+
+def _AddPropertiesForNonRepeatedCompositeField(field, cls):
+  """Adds a public property for a nonrepeated, composite protocol message field.
+  A composite field is a "group" or "message" field.
+
+  Clients can use this property to get the value of the field, but cannot
+  assign to the property directly.
+
+  Args:
+    field: A FieldDescriptor for this field.
+    cls: The class we're constructing.
+  """
+  # TODO(robinson): Remove duplication with similar method
+  # for non-repeated scalars.
+  proto_field_name = field.name
+  property_name = _PropertyName(proto_field_name)
+  message_type = field.message_type
+
+  def getter(self):
+    field_value = self._fields.get(field)
+    if field_value is None:
+      # Construct a new object to represent this field.
+      field_value = message_type._concrete_class()
+      field_value._SetListener(self._listener_for_children)
+
+      # Atomically check if another thread has preempted us and, if not, swap
+      # in the new object we just created.  If someone has preempted us, we
+      # take that object and discard ours.
+      # WARNING:  We are relying on setdefault() being atomic.  This is true
+      #   in CPython but we haven't investigated others.  This warning appears
+      #   in several other locations in this file.
+      field_value = self._fields.setdefault(field, field_value)
+    return field_value
+  getter.__module__ = None
+  getter.__doc__ = 'Getter for %s.' % proto_field_name
+
+  # We define a setter just so we can throw an exception with a more
+  # helpful error message.
+  def setter(self, new_value):
+    raise AttributeError('Assignment not allowed to composite field '
+                         '"%s" in protocol message object.' % proto_field_name)
+
+  # Add a property to encapsulate the getter.
+  doc = 'Magic attribute generated for "%s" proto field.' % proto_field_name
+  setattr(cls, property_name, property(getter, setter, doc=doc))
+
+
+def _AddPropertiesForExtensions(descriptor, cls):
+  """Adds properties for all fields in this protocol message type."""
+  extension_dict = descriptor.extensions_by_name
+  for extension_name, extension_field in extension_dict.iteritems():
+    constant_name = extension_name.upper() + "_FIELD_NUMBER"
+    setattr(cls, constant_name, extension_field.number)
+
+
+def _AddStaticMethods(cls):
+  # TODO(robinson): This probably needs to be thread-safe(?)
+  def RegisterExtension(extension_handle):
+    extension_handle.containing_type = cls.DESCRIPTOR
+    _AttachFieldHelpers(cls, extension_handle)
+
+    # Try to insert our extension, failing if an extension with the same number
+    # already exists.
+    actual_handle = cls._extensions_by_number.setdefault(
+        extension_handle.number, extension_handle)
+    if actual_handle is not extension_handle:
+      raise AssertionError(
+          'Extensions "%s" and "%s" both try to extend message type "%s" with '
+          'field number %d.' %
+          (extension_handle.full_name, actual_handle.full_name,
+           cls.DESCRIPTOR.full_name, extension_handle.number))
+
+    cls._extensions_by_name[extension_handle.full_name] = extension_handle
+
+    handle = extension_handle  # avoid line wrapping
+    if _IsMessageSetExtension(handle):
+      # MessageSet extension.  Also register under type name.
+      cls._extensions_by_name[
+          extension_handle.message_type.full_name] = extension_handle
+
+  cls.RegisterExtension = staticmethod(RegisterExtension)
+
+  def FromString(s):
+    message = cls()
+    message.MergeFromString(s)
+    return message
+  cls.FromString = staticmethod(FromString)
+
+
+def _IsPresent(item):
+  """Given a (FieldDescriptor, value) tuple from _fields, return true if the
+  value should be included in the list returned by ListFields()."""
+
+  if item[0].label == _FieldDescriptor.LABEL_REPEATED:
+    return bool(item[1])
+  elif item[0].cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE:
+    return item[1]._is_present_in_parent
+  else:
+    return True
+
+
+def _AddListFieldsMethod(message_descriptor, cls):
+  """Helper for _AddMessageMethods()."""
+
+  def ListFields(self):
+    all_fields = [item for item in self._fields.iteritems() if _IsPresent(item)]
+    all_fields.sort(key = lambda item: item[0].number)
+    return all_fields
+
+  cls.ListFields = ListFields
+
+
+def _AddHasFieldMethod(message_descriptor, cls):
+  """Helper for _AddMessageMethods()."""
+
+  singular_fields = {}
+  for field in message_descriptor.fields:
+    if field.label != _FieldDescriptor.LABEL_REPEATED:
+      singular_fields[field.name] = field
+
+  def HasField(self, field_name):
+    try:
+      field = singular_fields[field_name]
+    except KeyError:
+      raise ValueError(
+          'Protocol message has no singular "%s" field.' % field_name)
+
+    if field.cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE:
+      value = self._fields.get(field)
+      return value is not None and value._is_present_in_parent
+    else:
+      return field in self._fields
+  cls.HasField = HasField
+
+
+def _AddClearFieldMethod(message_descriptor, cls):
+  """Helper for _AddMessageMethods()."""
+  def ClearField(self, field_name):
+    try:
+      field = message_descriptor.fields_by_name[field_name]
+    except KeyError:
+      raise ValueError('Protocol message has no "%s" field.' % field_name)
+
+    if field in self._fields:
+      # Note:  If the field is a sub-message, its listener will still point
+      #   at us.  That's fine, because the worst than can happen is that it
+      #   will call _Modified() and invalidate our byte size.  Big deal.
+      del self._fields[field]
+
+    # Always call _Modified() -- even if nothing was changed, this is
+    # a mutating method, and thus calling it should cause the field to become
+    # present in the parent message.
+    self._Modified()
+
+  cls.ClearField = ClearField
+
+
+def _AddClearExtensionMethod(cls):
+  """Helper for _AddMessageMethods()."""
+  def ClearExtension(self, extension_handle):
+    _VerifyExtensionHandle(self, extension_handle)
+
+    # Similar to ClearField(), above.
+    if extension_handle in self._fields:
+      del self._fields[extension_handle]
+    self._Modified()
+  cls.ClearExtension = ClearExtension
+
+
+def _AddClearMethod(message_descriptor, cls):
+  """Helper for _AddMessageMethods()."""
+  def Clear(self):
+    # Clear fields.
+    self._fields = {}
+    self._Modified()
+  cls.Clear = Clear
+
+
+def _AddHasExtensionMethod(cls):
+  """Helper for _AddMessageMethods()."""
+  def HasExtension(self, extension_handle):
+    _VerifyExtensionHandle(self, extension_handle)
+    if extension_handle.label == _FieldDescriptor.LABEL_REPEATED:
+      raise KeyError('"%s" is repeated.' % extension_handle.full_name)
+
+    if extension_handle.cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE:
+      value = self._fields.get(extension_handle)
+      return value is not None and value._is_present_in_parent
+    else:
+      return extension_handle in self._fields
+  cls.HasExtension = HasExtension
+
+
+def _AddEqualsMethod(message_descriptor, cls):
+  """Helper for _AddMessageMethods()."""
+  def __eq__(self, other):
+    if (not isinstance(other, message_mod.Message) or
+        other.DESCRIPTOR != self.DESCRIPTOR):
+      return False
+
+    if self is other:
+      return True
+
+    return self.ListFields() == other.ListFields()
+
+  cls.__eq__ = __eq__
+
+
+def _AddStrMethod(message_descriptor, cls):
+  """Helper for _AddMessageMethods()."""
+  def __str__(self):
+    return text_format.MessageToString(self)
+  cls.__str__ = __str__
+
+
+def _AddUnicodeMethod(unused_message_descriptor, cls):
+  """Helper for _AddMessageMethods()."""
+
+  def __unicode__(self):
+    return text_format.MessageToString(self, as_utf8=True).decode('utf-8')
+  cls.__unicode__ = __unicode__
+
+
+def _AddSetListenerMethod(cls):
+  """Helper for _AddMessageMethods()."""
+  def SetListener(self, listener):
+    if listener is None:
+      self._listener = message_listener_mod.NullMessageListener()
+    else:
+      self._listener = listener
+  cls._SetListener = SetListener
+
+
+def _BytesForNonRepeatedElement(value, field_number, field_type):
+  """Returns the number of bytes needed to serialize a non-repeated element.
+  The returned byte count includes space for tag information and any
+  other additional space associated with serializing value.
+
+  Args:
+    value: Value we're serializing.
+    field_number: Field number of this value.  (Since the field number
+      is stored as part of a varint-encoded tag, this has an impact
+      on the total bytes required to serialize the value).
+    field_type: The type of the field.  One of the TYPE_* constants
+      within FieldDescriptor.
+  """
+  try:
+    fn = type_checkers.TYPE_TO_BYTE_SIZE_FN[field_type]
+    return fn(field_number, value)
+  except KeyError:
+    raise message_mod.EncodeError('Unrecognized field type: %d' % field_type)
+
+
+def _AddByteSizeMethod(message_descriptor, cls):
+  """Helper for _AddMessageMethods()."""
+
+  def ByteSize(self):
+    if not self._cached_byte_size_dirty:
+      return self._cached_byte_size
+
+    size = 0
+    for field_descriptor, field_value in self.ListFields():
+      size += field_descriptor._sizer(field_value)
+
+    self._cached_byte_size = size
+    self._cached_byte_size_dirty = False
+    self._listener_for_children.dirty = False
+    return size
+
+  cls.ByteSize = ByteSize
+
+
+def _AddSerializeToStringMethod(message_descriptor, cls):
+  """Helper for _AddMessageMethods()."""
+
+  def SerializeToString(self):
+    # Check if the message has all of its required fields set.
+    errors = []
+    if not self.IsInitialized():
+      raise message_mod.EncodeError(
+          'Message is missing required fields: ' +
+          ','.join(self.FindInitializationErrors()))
+    return self.SerializePartialToString()
+  cls.SerializeToString = SerializeToString
+
+
+def _AddSerializePartialToStringMethod(message_descriptor, cls):
+  """Helper for _AddMessageMethods()."""
+
+  def SerializePartialToString(self):
+    out = StringIO()
+    self._InternalSerialize(out.write)
+    return out.getvalue()
+  cls.SerializePartialToString = SerializePartialToString
+
+  def InternalSerialize(self, write_bytes):
+    for field_descriptor, field_value in self.ListFields():
+      field_descriptor._encoder(write_bytes, field_value)
+  cls._InternalSerialize = InternalSerialize
+
+
+def _AddMergeFromStringMethod(message_descriptor, cls):
+  """Helper for _AddMessageMethods()."""
+  def MergeFromString(self, serialized):
+    length = len(serialized)
+    try:
+      if self._InternalParse(serialized, 0, length) != length:
+        # The only reason _InternalParse would return early is if it
+        # encountered an end-group tag.
+        raise message_mod.DecodeError('Unexpected end-group tag.')
+    except IndexError:
+      raise message_mod.DecodeError('Truncated message.')
+    except struct.error, e:
+      raise message_mod.DecodeError(e)
+    return length   # Return this for legacy reasons.
+  cls.MergeFromString = MergeFromString
+
+  local_ReadTag = decoder.ReadTag
+  local_SkipField = decoder.SkipField
+  decoders_by_tag = cls._decoders_by_tag
+
+  def InternalParse(self, buffer, pos, end):
+    self._Modified()
+    field_dict = self._fields
+    while pos != end:
+      (tag_bytes, new_pos) = local_ReadTag(buffer, pos)
+      field_decoder = decoders_by_tag.get(tag_bytes)
+      if field_decoder is None:
+        new_pos = local_SkipField(buffer, new_pos, end, tag_bytes)
+        if new_pos == -1:
+          return pos
+        pos = new_pos
+      else:
+        pos = field_decoder(buffer, new_pos, end, self, field_dict)
+    return pos
+  cls._InternalParse = InternalParse
+
+
+def _AddIsInitializedMethod(message_descriptor, cls):
+  """Adds the IsInitialized and FindInitializationError methods to the
+  protocol message class."""
+
+  required_fields = [field for field in message_descriptor.fields
+                           if field.label == _FieldDescriptor.LABEL_REQUIRED]
+
+  def IsInitialized(self, errors=None):
+    """Checks if all required fields of a message are set.
+
+    Args:
+      errors:  A list which, if provided, will be populated with the field
+               paths of all missing required fields.
+
+    Returns:
+      True iff the specified message has all required fields set.
+    """
+
+    # Performance is critical so we avoid HasField() and ListFields().
+
+    for field in required_fields:
+      if (field not in self._fields or
+          (field.cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE and
+           not self._fields[field]._is_present_in_parent)):
+        if errors is not None:
+          errors.extend(self.FindInitializationErrors())
+        return False
+
+    for field, value in self._fields.iteritems():
+      if field.cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE:
+        if field.label == _FieldDescriptor.LABEL_REPEATED:
+          for element in value:
+            if not element.IsInitialized():
+              if errors is not None:
+                errors.extend(self.FindInitializationErrors())
+              return False
+        elif value._is_present_in_parent and not value.IsInitialized():
+          if errors is not None:
+            errors.extend(self.FindInitializationErrors())
+          return False
+
+    return True
+
+  cls.IsInitialized = IsInitialized
+
+  def FindInitializationErrors(self):
+    """Finds required fields which are not initialized.
+
+    Returns:
+      A list of strings.  Each string is a path to an uninitialized field from
+      the top-level message, e.g. "foo.bar[5].baz".
+    """
+
+    errors = []  # simplify things
+
+    for field in required_fields:
+      if not self.HasField(field.name):
+        errors.append(field.name)
+
+    for field, value in self.ListFields():
+      if field.cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE:
+        if field.is_extension:
+          name = "(%s)" % field.full_name
+        else:
+          name = field.name
+
+        if field.label == _FieldDescriptor.LABEL_REPEATED:
+          for i in xrange(len(value)):
+            element = value[i]
+            prefix = "%s[%d]." % (name, i)
+            sub_errors = element.FindInitializationErrors()
+            errors += [ prefix + error for error in sub_errors ]
+        else:
+          prefix = name + "."
+          sub_errors = value.FindInitializationErrors()
+          errors += [ prefix + error for error in sub_errors ]
+
+    return errors
+
+  cls.FindInitializationErrors = FindInitializationErrors
+
+
+def _AddMergeFromMethod(cls):
+  LABEL_REPEATED = _FieldDescriptor.LABEL_REPEATED
+  CPPTYPE_MESSAGE = _FieldDescriptor.CPPTYPE_MESSAGE
+
+  def MergeFrom(self, msg):
+    if not isinstance(msg, cls):
+      raise TypeError(
+          "Parameter to MergeFrom() must be instance of same class.")
+
+    assert msg is not self
+    self._Modified()
+
+    fields = self._fields
+
+    for field, value in msg._fields.iteritems():
+      if field.label == LABEL_REPEATED:
+        field_value = fields.get(field)
+        if field_value is None:
+          # Construct a new object to represent this field.
+          field_value = field._default_constructor(self)
+          fields[field] = field_value
+        field_value.MergeFrom(value)
+      elif field.cpp_type == CPPTYPE_MESSAGE:
+        if value._is_present_in_parent:
+          field_value = fields.get(field)
+          if field_value is None:
+            # Construct a new object to represent this field.
+            field_value = field._default_constructor(self)
+            fields[field] = field_value
+          field_value.MergeFrom(value)
+      else:
+        self._fields[field] = value
+  cls.MergeFrom = MergeFrom
+
+
+def _AddMessageMethods(message_descriptor, cls):
+  """Adds implementations of all Message methods to cls."""
+  _AddListFieldsMethod(message_descriptor, cls)
+  _AddHasFieldMethod(message_descriptor, cls)
+  _AddClearFieldMethod(message_descriptor, cls)
+  if message_descriptor.is_extendable:
+    _AddClearExtensionMethod(cls)
+    _AddHasExtensionMethod(cls)
+  _AddClearMethod(message_descriptor, cls)
+  _AddEqualsMethod(message_descriptor, cls)
+  _AddStrMethod(message_descriptor, cls)
+  _AddUnicodeMethod(message_descriptor, cls)
+  _AddSetListenerMethod(cls)
+  _AddByteSizeMethod(message_descriptor, cls)
+  _AddSerializeToStringMethod(message_descriptor, cls)
+  _AddSerializePartialToStringMethod(message_descriptor, cls)
+  _AddMergeFromStringMethod(message_descriptor, cls)
+  _AddIsInitializedMethod(message_descriptor, cls)
+  _AddMergeFromMethod(cls)
+
+
+def _AddPrivateHelperMethods(cls):
+  """Adds implementation of private helper methods to cls."""
+
+  def Modified(self):
+    """Sets the _cached_byte_size_dirty bit to true,
+    and propagates this to our listener iff this was a state change.
+    """
+
+    # Note:  Some callers check _cached_byte_size_dirty before calling
+    #   _Modified() as an extra optimization.  So, if this method is ever
+    #   changed such that it does stuff even when _cached_byte_size_dirty is
+    #   already true, the callers need to be updated.
+    if not self._cached_byte_size_dirty:
+      self._cached_byte_size_dirty = True
+      self._listener_for_children.dirty = True
+      self._is_present_in_parent = True
+      self._listener.Modified()
+
+  cls._Modified = Modified
+  cls.SetInParent = Modified
+
+
+class _Listener(object):
+
+  """MessageListener implementation that a parent message registers with its
+  child message.
+
+  In order to support semantics like:
+
+    foo.bar.baz.qux = 23
+    assert foo.HasField('bar')
+
+  ...child objects must have back references to their parents.
+  This helper class is at the heart of this support.
+  """
+
+  def __init__(self, parent_message):
+    """Args:
+      parent_message: The message whose _Modified() method we should call when
+        we receive Modified() messages.
+    """
+    # This listener establishes a back reference from a child (contained) object
+    # to its parent (containing) object.  We make this a weak reference to avoid
+    # creating cyclic garbage when the client finishes with the 'parent' object
+    # in the tree.
+    if isinstance(parent_message, weakref.ProxyType):
+      self._parent_message_weakref = parent_message
+    else:
+      self._parent_message_weakref = weakref.proxy(parent_message)
+
+    # As an optimization, we also indicate directly on the listener whether
+    # or not the parent message is dirty.  This way we can avoid traversing
+    # up the tree in the common case.
+    self.dirty = False
+
+  def Modified(self):
+    if self.dirty:
+      return
+    try:
+      # Propagate the signal to our parents iff this is the first field set.
+      self._parent_message_weakref._Modified()
+    except ReferenceError:
+      # We can get here if a client has kept a reference to a child object,
+      # and is now setting a field on it, but the child's parent has been
+      # garbage-collected.  This is not an error.
+      pass
+
+
+# TODO(robinson): Move elsewhere?  This file is getting pretty ridiculous...
+# TODO(robinson): Unify error handling of "unknown extension" crap.
+# TODO(robinson): Support iteritems()-style iteration over all
+# extensions with the "has" bits turned on?
+class _ExtensionDict(object):
+
+  """Dict-like container for supporting an indexable "Extensions"
+  field on proto instances.
+
+  Note that in all cases we expect extension handles to be
+  FieldDescriptors.
+  """
+
+  def __init__(self, extended_message):
+    """extended_message: Message instance for which we are the Extensions dict.
+    """
+
+    self._extended_message = extended_message
+
+  def __getitem__(self, extension_handle):
+    """Returns the current value of the given extension handle."""
+
+    _VerifyExtensionHandle(self._extended_message, extension_handle)
+
+    result = self._extended_message._fields.get(extension_handle)
+    if result is not None:
+      return result
+
+    if extension_handle.label == _FieldDescriptor.LABEL_REPEATED:
+      result = extension_handle._default_constructor(self._extended_message)
+    elif extension_handle.cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE:
+      result = extension_handle.message_type._concrete_class()
+      try:
+        result._SetListener(self._extended_message._listener_for_children)
+      except ReferenceError:
+        pass
+    else:
+      # Singular scalar -- just return the default without inserting into the
+      # dict.
+      return extension_handle.default_value
+
+    # Atomically check if another thread has preempted us and, if not, swap
+    # in the new object we just created.  If someone has preempted us, we
+    # take that object and discard ours.
+    # WARNING:  We are relying on setdefault() being atomic.  This is true
+    #   in CPython but we haven't investigated others.  This warning appears
+    #   in several other locations in this file.
+    result = self._extended_message._fields.setdefault(
+        extension_handle, result)
+
+    return result
+
+  def __eq__(self, other):
+    if not isinstance(other, self.__class__):
+      return False
+
+    my_fields = self._extended_message.ListFields()
+    other_fields = other._extended_message.ListFields()
+
+    # Get rid of non-extension fields.
+    my_fields    = [ field for field in my_fields    if field.is_extension ]
+    other_fields = [ field for field in other_fields if field.is_extension ]
+
+    return my_fields == other_fields
+
+  def __ne__(self, other):
+    return not self == other
+
+  def __hash__(self):
+    raise TypeError('unhashable object')
+
+  # Note that this is only meaningful for non-repeated, scalar extension
+  # fields.  Note also that we may have to call _Modified() when we do
+  # successfully set a field this way, to set any necssary "has" bits in the
+  # ancestors of the extended message.
+  def __setitem__(self, extension_handle, value):
+    """If extension_handle specifies a non-repeated, scalar extension
+    field, sets the value of that field.
+    """
+
+    _VerifyExtensionHandle(self._extended_message, extension_handle)
+
+    if (extension_handle.label == _FieldDescriptor.LABEL_REPEATED or
+        extension_handle.cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE):
+      raise TypeError(
+          'Cannot assign to extension "%s" because it is a repeated or '
+          'composite type.' % extension_handle.full_name)
+
+    # It's slightly wasteful to lookup the type checker each time,
+    # but we expect this to be a vanishingly uncommon case anyway.
+    type_checker = type_checkers.GetTypeChecker(
+        extension_handle.cpp_type, extension_handle.type)
+    type_checker.CheckValue(value)
+    self._extended_message._fields[extension_handle] = value
+    self._extended_message._Modified()
+
+  def _FindExtensionByName(self, name):
+    """Tries to find a known extension with the specified name.
+
+    Args:
+      name: Extension full name.
+
+    Returns:
+      Extension field descriptor.
+    """
+    return self._extended_message._extensions_by_name.get(name, None)
diff --git a/python/google/protobuf/internal/reflection_test.py b/python/google/protobuf/internal/reflection_test.py
index 54eeebe6..7b9d3398 100755
--- a/python/google/protobuf/internal/reflection_test.py
+++ b/python/google/protobuf/internal/reflection_test.py
@@ -41,8 +41,6 @@ import operator
 import struct
 
 import unittest
-# TODO(robinson): When we split this test in two, only some of these imports
-# will be necessary in each test.
 from google.protobuf import unittest_import_pb2
 from google.protobuf import unittest_mset_pb2
 from google.protobuf import unittest_pb2
@@ -50,6 +48,7 @@ from google.protobuf import descriptor_pb2
 from google.protobuf import descriptor
 from google.protobuf import message
 from google.protobuf import reflection
+from google.protobuf.internal import api_implementation
 from google.protobuf.internal import more_extensions_pb2
 from google.protobuf.internal import more_messages_pb2
 from google.protobuf.internal import wire_format
@@ -104,10 +103,10 @@ class _MiniDecoder(object):
 
 class ReflectionTest(unittest.TestCase):
 
-  def assertIs(self, values, others):
+  def assertListsEqual(self, values, others):
     self.assertEqual(len(values), len(others))
     for i in range(len(values)):
-      self.assertTrue(values[i] is others[i])
+      self.assertEqual(values[i], others[i])
 
   def testScalarConstructor(self):
     # Constructor with only scalar types should succeed.
@@ -201,15 +200,24 @@ class ReflectionTest(unittest.TestCase):
         list(proto.repeated_foreign_message))
 
   def testConstructorTypeError(self):
-    self.assertRaises(TypeError, unittest_pb2.TestAllTypes, optional_int32="foo")
-    self.assertRaises(TypeError, unittest_pb2.TestAllTypes, optional_string=1234)
-    self.assertRaises(TypeError, unittest_pb2.TestAllTypes, optional_nested_message=1234)
-    self.assertRaises(TypeError, unittest_pb2.TestAllTypes, repeated_int32=1234)
-    self.assertRaises(TypeError, unittest_pb2.TestAllTypes, repeated_int32=["foo"])
-    self.assertRaises(TypeError, unittest_pb2.TestAllTypes, repeated_string=1234)
-    self.assertRaises(TypeError, unittest_pb2.TestAllTypes, repeated_string=[1234])
-    self.assertRaises(TypeError, unittest_pb2.TestAllTypes, repeated_nested_message=1234)
-    self.assertRaises(TypeError, unittest_pb2.TestAllTypes, repeated_nested_message=[1234])
+    self.assertRaises(
+        TypeError, unittest_pb2.TestAllTypes, optional_int32="foo")
+    self.assertRaises(
+        TypeError, unittest_pb2.TestAllTypes, optional_string=1234)
+    self.assertRaises(
+        TypeError, unittest_pb2.TestAllTypes, optional_nested_message=1234)
+    self.assertRaises(
+        TypeError, unittest_pb2.TestAllTypes, repeated_int32=1234)
+    self.assertRaises(
+        TypeError, unittest_pb2.TestAllTypes, repeated_int32=["foo"])
+    self.assertRaises(
+        TypeError, unittest_pb2.TestAllTypes, repeated_string=1234)
+    self.assertRaises(
+        TypeError, unittest_pb2.TestAllTypes, repeated_string=[1234])
+    self.assertRaises(
+        TypeError, unittest_pb2.TestAllTypes, repeated_nested_message=1234)
+    self.assertRaises(
+        TypeError, unittest_pb2.TestAllTypes, repeated_nested_message=[1234])
 
   def testConstructorInvalidatesCachedByteSize(self):
     message = unittest_pb2.TestAllTypes(optional_int32 = 12)
@@ -311,11 +319,14 @@ class ReflectionTest(unittest.TestCase):
       self.assertEqual(0, getattr(composite_field, scalar_field_name))
 
       # Finally, ensure that modifications to the old composite field object
-      # don't have any effect on the parent.
+      # don't have any effect on the parent. Possible only with the pure-python
+      # implementation of the API.
       #
       # (NOTE that when we clear the composite field in the parent, we actually
       # don't recursively clear down the tree.  Instead, we just disconnect the
       # cleared composite from the tree.)
+      if api_implementation.Type() != 'python':
+        return
       self.assertTrue(old_composite_field is not composite_field)
       setattr(old_composite_field, scalar_field_name, new_val)
       self.assertTrue(not composite_field.HasField(scalar_field_name))
@@ -337,6 +348,8 @@ class ReflectionTest(unittest.TestCase):
     nested.bb = 23
 
   def testDisconnectingNestedMessageBeforeSettingField(self):
+    if api_implementation.Type() != 'python':
+      return
     proto = unittest_pb2.TestAllTypes()
     nested = proto.optional_nested_message
     proto.ClearField('optional_nested_message')  # Should disconnect from parent
@@ -526,7 +539,6 @@ class ReflectionTest(unittest.TestCase):
     # proto.nonexistent_field = 23 should fail as well.
     self.assertRaises(AttributeError, setattr, proto, 'nonexistent_field', 23)
 
-  # TODO(robinson): Add type-safety check for enums.
   def testSingleScalarTypeSafety(self):
     proto = unittest_pb2.TestAllTypes()
     self.assertRaises(TypeError, setattr, proto, 'optional_int32', 1.1)
@@ -538,7 +550,9 @@ class ReflectionTest(unittest.TestCase):
     def TestMinAndMaxIntegers(field_name, expected_min, expected_max):
       pb = unittest_pb2.TestAllTypes()
       setattr(pb, field_name, expected_min)
+      self.assertEqual(expected_min, getattr(pb, field_name))
       setattr(pb, field_name, expected_max)
+      self.assertEqual(expected_max, getattr(pb, field_name))
       self.assertRaises(ValueError, setattr, pb, field_name, expected_min - 1)
       self.assertRaises(ValueError, setattr, pb, field_name, expected_max + 1)
 
@@ -546,7 +560,33 @@ class ReflectionTest(unittest.TestCase):
     TestMinAndMaxIntegers('optional_uint32', 0, 0xffffffff)
     TestMinAndMaxIntegers('optional_int64', -(1 << 63), (1 << 63) - 1)
     TestMinAndMaxIntegers('optional_uint64', 0, 0xffffffffffffffff)
-    TestMinAndMaxIntegers('optional_nested_enum', -(1 << 31), (1 << 31) - 1)
+
+    pb = unittest_pb2.TestAllTypes()
+    pb.optional_nested_enum = 1
+    self.assertEqual(1, pb.optional_nested_enum)
+
+    # Invalid enum values.
+    pb.optional_nested_enum = 0
+    self.assertEqual(0, pb.optional_nested_enum)
+
+    bytes_size_before = pb.ByteSize()
+
+    pb.optional_nested_enum = 4
+    self.assertEqual(4, pb.optional_nested_enum)
+
+    pb.optional_nested_enum = 0
+    self.assertEqual(0, pb.optional_nested_enum)
+
+    # Make sure that setting the same enum field doesn't just add unknown
+    # fields (but overwrites them).
+    self.assertEqual(bytes_size_before, pb.ByteSize())
+
+    # Is the invalid value preserved after serialization?
+    serialized = pb.SerializeToString()
+    pb2 = unittest_pb2.TestAllTypes()
+    pb2.ParseFromString(serialized)
+    self.assertEqual(0, pb2.optional_nested_enum)
+    self.assertEqual(pb, pb2)
 
   def testRepeatedScalarTypeSafety(self):
     proto = unittest_pb2.TestAllTypes()
@@ -560,11 +600,19 @@ class ReflectionTest(unittest.TestCase):
     self.assertRaises(IndexError, proto.repeated_int32.__setitem__, 500, 23)
     self.assertRaises(TypeError, proto.repeated_int32.__setitem__, 0, 'abc')
 
+    # Repeated enums tests.
+    #proto.repeated_nested_enum.append(0)
+
   def testSingleScalarGettersAndSetters(self):
     proto = unittest_pb2.TestAllTypes()
     self.assertEqual(0, proto.optional_int32)
     proto.optional_int32 = 1
     self.assertEqual(1, proto.optional_int32)
+
+    proto.optional_uint64 = 0xffffffffffff
+    self.assertEqual(0xffffffffffff, proto.optional_uint64)
+    proto.optional_uint64 = 0xffffffffffffffff
+    self.assertEqual(0xffffffffffffffff, proto.optional_uint64)
     # TODO(robinson): Test all other scalar field types.
 
   def testSingleScalarClearField(self):
@@ -645,11 +693,38 @@ class ReflectionTest(unittest.TestCase):
     del proto.repeated_int32[2:]
     self.assertEqual([5, 35], proto.repeated_int32)
 
+    # Test extending.
+    proto.repeated_int32.extend([3, 13])
+    self.assertEqual([5, 35, 3, 13], proto.repeated_int32)
+
     # Test clearing.
     proto.ClearField('repeated_int32')
     self.assertTrue(not proto.repeated_int32)
     self.assertEqual(0, len(proto.repeated_int32))
 
+    proto.repeated_int32.append(1)
+    self.assertEqual(1, proto.repeated_int32[-1])
+    # Test assignment to a negative index.
+    proto.repeated_int32[-1] = 2
+    self.assertEqual(2, proto.repeated_int32[-1])
+
+    # Test deletion at negative indices.
+    proto.repeated_int32[:] = [0, 1, 2, 3]
+    del proto.repeated_int32[-1]
+    self.assertEqual([0, 1, 2], proto.repeated_int32)
+
+    del proto.repeated_int32[-2]
+    self.assertEqual([0, 2], proto.repeated_int32)
+
+    self.assertRaises(IndexError, proto.repeated_int32.__delitem__, -3)
+    self.assertRaises(IndexError, proto.repeated_int32.__delitem__, 300)
+
+    del proto.repeated_int32[-2:-1]
+    self.assertEqual([2], proto.repeated_int32)
+
+    del proto.repeated_int32[100:10000]
+    self.assertEqual([2], proto.repeated_int32)
+
   def testRepeatedScalarsRemove(self):
     proto = unittest_pb2.TestAllTypes()
 
@@ -687,7 +762,7 @@ class ReflectionTest(unittest.TestCase):
     m1 = proto.repeated_nested_message.add()
     self.assertTrue(proto.repeated_nested_message)
     self.assertEqual(2, len(proto.repeated_nested_message))
-    self.assertIs([m0, m1], proto.repeated_nested_message)
+    self.assertListsEqual([m0, m1], proto.repeated_nested_message)
     self.assertTrue(isinstance(m0, unittest_pb2.TestAllTypes.NestedMessage))
 
     # Test out-of-bounds indices.
@@ -706,32 +781,57 @@ class ReflectionTest(unittest.TestCase):
     m2 = proto.repeated_nested_message.add()
     m3 = proto.repeated_nested_message.add()
     m4 = proto.repeated_nested_message.add()
-    self.assertIs([m1, m2, m3], proto.repeated_nested_message[1:4])
-    self.assertIs([m0, m1, m2, m3, m4], proto.repeated_nested_message[:])
+    self.assertListsEqual(
+        [m1, m2, m3], proto.repeated_nested_message[1:4])
+    self.assertListsEqual(
+        [m0, m1, m2, m3, m4], proto.repeated_nested_message[:])
+    self.assertListsEqual(
+        [m0, m1], proto.repeated_nested_message[:2])
+    self.assertListsEqual(
+        [m2, m3, m4], proto.repeated_nested_message[2:])
+    self.assertEqual(
+        m0, proto.repeated_nested_message[0])
+    self.assertListsEqual(
+        [m0], proto.repeated_nested_message[:1])
 
     # Test that we can use the field as an iterator.
     result = []
     for i in proto.repeated_nested_message:
       result.append(i)
-    self.assertIs([m0, m1, m2, m3, m4], result)
+    self.assertListsEqual([m0, m1, m2, m3, m4], result)
 
     # Test single deletion.
     del proto.repeated_nested_message[2]
-    self.assertIs([m0, m1, m3, m4], proto.repeated_nested_message)
+    self.assertListsEqual([m0, m1, m3, m4], proto.repeated_nested_message)
 
     # Test slice deletion.
     del proto.repeated_nested_message[2:]
-    self.assertIs([m0, m1], proto.repeated_nested_message)
+    self.assertListsEqual([m0, m1], proto.repeated_nested_message)
+
+    # Test extending.
+    n1 = unittest_pb2.TestAllTypes.NestedMessage(bb=1)
+    n2 = unittest_pb2.TestAllTypes.NestedMessage(bb=2)
+    proto.repeated_nested_message.extend([n1,n2])
+    self.assertEqual(4, len(proto.repeated_nested_message))
+    self.assertEqual(n1, proto.repeated_nested_message[2])
+    self.assertEqual(n2, proto.repeated_nested_message[3])
 
     # Test clearing.
     proto.ClearField('repeated_nested_message')
     self.assertTrue(not proto.repeated_nested_message)
     self.assertEqual(0, len(proto.repeated_nested_message))
 
+    # Test constructing an element while adding it.
+    proto.repeated_nested_message.add(bb=23)
+    self.assertEqual(1, len(proto.repeated_nested_message))
+    self.assertEqual(23, proto.repeated_nested_message[0].bb)
+
   def testHandWrittenReflection(self):
-    # TODO(robinson): We probably need a better way to specify
-    # protocol types by hand.  But then again, this isn't something
-    # we expect many people to do.  Hmm.
+    # Hand written extensions are only supported by the pure-Python
+    # implementation of the API.
+    if api_implementation.Type() != 'python':
+      return
+
     FieldDescriptor = descriptor.FieldDescriptor
     foo_field_descriptor = FieldDescriptor(
         name='foo_field', full_name='MyProto.foo_field',
@@ -894,7 +994,7 @@ class ReflectionTest(unittest.TestCase):
     self.assertTrue(not toplevel.HasField('submessage'))
     foreign = toplevel.submessage.Extensions[
         more_extensions_pb2.repeated_message_extension].add()
-    self.assertTrue(foreign is toplevel.submessage.Extensions[
+    self.assertEqual(foreign, toplevel.submessage.Extensions[
         more_extensions_pb2.repeated_message_extension][0])
     self.assertTrue(toplevel.HasField('submessage'))
 
@@ -997,6 +1097,12 @@ class ReflectionTest(unittest.TestCase):
     self.assertEqual(123, proto2.repeated_nested_message[1].bb)
     self.assertEqual(321, proto2.repeated_nested_message[2].bb)
 
+    proto3 = unittest_pb2.TestAllTypes()
+    proto3.repeated_nested_message.MergeFrom(proto2.repeated_nested_message)
+    self.assertEqual(999, proto3.repeated_nested_message[0].bb)
+    self.assertEqual(123, proto3.repeated_nested_message[1].bb)
+    self.assertEqual(321, proto3.repeated_nested_message[2].bb)
+
   def testMergeFromAllFields(self):
     # With all fields set.
     proto1 = unittest_pb2.TestAllTypes()
@@ -1126,6 +1232,15 @@ class ReflectionTest(unittest.TestCase):
     self.assertEqual(2, proto1.optional_int32)
     self.assertEqual('important-text', proto1.optional_string)
 
+  def testCopyFromBadType(self):
+    # The python implementation doesn't raise an exception in this
+    # case. In theory it should.
+    if api_implementation.Type() == 'python':
+      return
+    proto1 = unittest_pb2.TestAllTypes()
+    proto2 = unittest_pb2.TestAllExtensions()
+    self.assertRaises(TypeError, proto1.CopyFrom, proto2)
+
   def testClear(self):
     proto = unittest_pb2.TestAllTypes()
     test_util.SetAllFields(proto)
@@ -1231,9 +1346,10 @@ class ReflectionTest(unittest.TestCase):
     proto.optional_string = str('Testing')
     self.assertEqual(proto.optional_string, unicode('Testing'))
 
-    # Values of type 'str' are also accepted as long as they can be encoded in
-    # UTF-8.
-    self.assertEqual(type(proto.optional_string), str)
+    if api_implementation.Type() == 'python':
+      # Values of type 'str' are also accepted as long as they can be
+      # encoded in UTF-8.
+      self.assertEqual(type(proto.optional_string), str)
 
     # Try to assign a 'str' value which contains bytes that aren't 7-bit ASCII.
     self.assertRaises(ValueError,
@@ -1271,7 +1387,7 @@ class ReflectionTest(unittest.TestCase):
     # Check that the type_id is the same as the tag ID in the .proto file.
     self.assertEqual(raw.item[0].type_id, 1547769)
 
-    # Check the actually bytes on the wire.
+    # Check the actual bytes on the wire.
     self.assertTrue(
         raw.item[0].message.endswith(test_utf8_bytes))
     message2.MergeFromString(raw.item[0].message)
@@ -1279,10 +1395,23 @@ class ReflectionTest(unittest.TestCase):
     self.assertEqual(type(message2.str), unicode)
     self.assertEqual(message2.str, test_utf8)
 
-    # How about if the bytes on the wire aren't a valid UTF-8 encoded string.
+    # The pure Python API throws an exception on MergeFromString(),
+    # if any of the string fields of the message can't be UTF-8 decoded.
+    # The C++ implementation of the API has no way to check that on
+    # MergeFromString and thus has no way to throw the exception.
+    #
+    # The pure Python API always returns objects of type 'unicode' (UTF-8
+    # encoded), or 'str' (in 7 bit ASCII).
     bytes = raw.item[0].message.replace(
         test_utf8_bytes, len(test_utf8_bytes) * '\xff')
-    self.assertRaises(UnicodeDecodeError, message2.MergeFromString, bytes)
+
+    unicode_decode_failed = False
+    try:
+      message2.MergeFromString(bytes)
+    except UnicodeDecodeError, e:
+      unicode_decode_failed = True
+    string_field = message2.str
+    self.assertTrue(unicode_decode_failed or type(string_field) == str)
 
   def testEmptyNestedMessage(self):
     proto = unittest_pb2.TestAllTypes()
@@ -1325,6 +1454,9 @@ class TestAllTypesEqualityTest(unittest.TestCase):
     self.first_proto = unittest_pb2.TestAllTypes()
     self.second_proto = unittest_pb2.TestAllTypes()
 
+  def testNotHashable(self):
+    self.assertRaises(TypeError, hash, self.first_proto)
+
   def testSelfEquality(self):
     self.assertEqual(self.first_proto, self.first_proto)
 
@@ -1342,6 +1474,9 @@ class FullProtosEqualityTest(unittest.TestCase):
     test_util.SetAllFields(self.first_proto)
     test_util.SetAllFields(self.second_proto)
 
+  def testNotHashable(self):
+    self.assertRaises(TypeError, hash, self.first_proto)
+
   def testNoneNotEqual(self):
     self.assertNotEqual(self.first_proto, None)
     self.assertNotEqual(None, self.second_proto)
@@ -1410,9 +1545,6 @@ class FullProtosEqualityTest(unittest.TestCase):
     self.first_proto.ClearField('optional_nested_message')
     self.second_proto.optional_nested_message.ClearField('bb')
     self.assertNotEqual(self.first_proto, self.second_proto)
-    # TODO(robinson): Replace next two lines with method
-    # to set the "has" bit without changing the value,
-    # if/when such a method exists.
     self.first_proto.optional_nested_message.bb = 0
     self.first_proto.optional_nested_message.ClearField('bb')
     self.assertEqual(self.first_proto, self.second_proto)
@@ -1477,6 +1609,14 @@ class ByteSizeTest(unittest.TestCase):
   def testEmptyMessage(self):
     self.assertEqual(0, self.proto.ByteSize())
 
+  def testSizedOnKwargs(self):
+    # Use a separate message to ensure testing right after creation.
+    proto = unittest_pb2.TestAllTypes()
+    self.assertEqual(0, proto.ByteSize())
+    proto_kwargs = unittest_pb2.TestAllTypes(optional_int64 = 1)
+    # One byte for the tag, one to encode varint 1.
+    self.assertEqual(2, proto_kwargs.ByteSize())
+
   def testVarints(self):
     def Test(i, expected_varint_size):
       self.proto.Clear()
@@ -1668,10 +1808,13 @@ class ByteSizeTest(unittest.TestCase):
     self.assertEqual(3, self.proto.ByteSize())
     self.proto.ClearField('optional_foreign_message')
     self.assertEqual(0, self.proto.ByteSize())
-    child = self.proto.optional_foreign_message
-    self.proto.ClearField('optional_foreign_message')
-    child.c = 128
-    self.assertEqual(0, self.proto.ByteSize())
+
+    if api_implementation.Type() == 'python':
+      # This is only possible in pure-Python implementation of the API.
+      child = self.proto.optional_foreign_message
+      self.proto.ClearField('optional_foreign_message')
+      child.c = 128
+      self.assertEqual(0, self.proto.ByteSize())
 
     # Test within extension.
     extension = more_extensions_pb2.optional_message_extension
@@ -1737,7 +1880,6 @@ class ByteSizeTest(unittest.TestCase):
     self.assertEqual(19, self.packed_extended_proto.ByteSize())
 
 
-# TODO(robinson): We need cross-language serialization consistency tests.
 # Issues to be sure to cover include:
 #   * Handling of unrecognized tags ("uninterpreted_bytes").
 #   * Handling of MessageSets.
@@ -1792,6 +1934,10 @@ class SerializationTest(unittest.TestCase):
     self.assertEqual(first_proto, second_proto)
 
   def testParseTruncated(self):
+    # This test is only applicable for the Python implementation of the API.
+    if api_implementation.Type() != 'python':
+      return
+
     first_proto = unittest_pb2.TestAllTypes()
     test_util.SetAllFields(first_proto)
     serialized = first_proto.SerializeToString()
diff --git a/python/google/protobuf/internal/text_format_test.py b/python/google/protobuf/internal/text_format_test.py
index e0991cb1..a3547782 100755
--- a/python/google/protobuf/internal/text_format_test.py
+++ b/python/google/protobuf/internal/text_format_test.py
@@ -35,6 +35,7 @@
 __author__ = 'kenton@google.com (Kenton Varda)'
 
 import difflib
+import re
 
 import unittest
 from google.protobuf import text_format
@@ -95,12 +96,13 @@ class TextFormatTest(unittest.TestCase):
 
   def testPrintExotic(self):
     message = unittest_pb2.TestAllTypes()
-    message.repeated_int64.append(-9223372036854775808);
-    message.repeated_uint64.append(18446744073709551615);
-    message.repeated_double.append(123.456);
-    message.repeated_double.append(1.23e22);
-    message.repeated_double.append(1.23e-18);
-    message.repeated_string.append('\000\001\a\b\f\n\r\t\v\\\'\"');
+    message.repeated_int64.append(-9223372036854775808)
+    message.repeated_uint64.append(18446744073709551615)
+    message.repeated_double.append(123.456)
+    message.repeated_double.append(1.23e22)
+    message.repeated_double.append(1.23e-18)
+    message.repeated_string.append('\000\001\a\b\f\n\r\t\v\\\'"')
+    message.repeated_string.append(u'\u00fc\ua71f')
     self.CompareToGoldenText(
       self.RemoveRedundantZeros(text_format.MessageToString(message)),
       'repeated_int64: -9223372036854775808\n'
@@ -109,7 +111,95 @@ class TextFormatTest(unittest.TestCase):
       'repeated_double: 1.23e+22\n'
       'repeated_double: 1.23e-18\n'
       'repeated_string: '
-        '\"\\000\\001\\007\\010\\014\\n\\r\\t\\013\\\\\\\'\\\"\"\n')
+        '"\\000\\001\\007\\010\\014\\n\\r\\t\\013\\\\\\\'\\""\n'
+      'repeated_string: "\\303\\274\\352\\234\\237"\n')
+
+  def testPrintNestedMessageAsOneLine(self):
+    message = unittest_pb2.TestAllTypes()
+    msg = message.repeated_nested_message.add()
+    msg.bb = 42;
+    self.CompareToGoldenText(
+        text_format.MessageToString(message, as_one_line=True),
+        'repeated_nested_message { bb: 42 }')
+
+  def testPrintRepeatedFieldsAsOneLine(self):
+    message = unittest_pb2.TestAllTypes()
+    message.repeated_int32.append(1)
+    message.repeated_int32.append(1)
+    message.repeated_int32.append(3)
+    message.repeated_string.append("Google")
+    message.repeated_string.append("Zurich")
+    self.CompareToGoldenText(
+        text_format.MessageToString(message, as_one_line=True),
+        'repeated_int32: 1 repeated_int32: 1 repeated_int32: 3 '
+        'repeated_string: "Google" repeated_string: "Zurich"')
+
+  def testPrintNestedNewLineInStringAsOneLine(self):
+    message = unittest_pb2.TestAllTypes()
+    message.optional_string = "a\nnew\nline"
+    self.CompareToGoldenText(
+        text_format.MessageToString(message, as_one_line=True),
+        'optional_string: "a\\nnew\\nline"')
+
+  def testPrintMessageSetAsOneLine(self):
+    message = unittest_mset_pb2.TestMessageSetContainer()
+    ext1 = unittest_mset_pb2.TestMessageSetExtension1.message_set_extension
+    ext2 = unittest_mset_pb2.TestMessageSetExtension2.message_set_extension
+    message.message_set.Extensions[ext1].i = 23
+    message.message_set.Extensions[ext2].str = 'foo'
+    self.CompareToGoldenText(
+        text_format.MessageToString(message, as_one_line=True),
+        'message_set {'
+        ' [protobuf_unittest.TestMessageSetExtension1] {'
+        ' i: 23'
+        ' }'
+        ' [protobuf_unittest.TestMessageSetExtension2] {'
+        ' str: \"foo\"'
+        ' }'
+        ' }')
+
+  def testPrintExoticAsOneLine(self):
+    message = unittest_pb2.TestAllTypes()
+    message.repeated_int64.append(-9223372036854775808)
+    message.repeated_uint64.append(18446744073709551615)
+    message.repeated_double.append(123.456)
+    message.repeated_double.append(1.23e22)
+    message.repeated_double.append(1.23e-18)
+    message.repeated_string.append('\000\001\a\b\f\n\r\t\v\\\'"')
+    message.repeated_string.append(u'\u00fc\ua71f')
+    self.CompareToGoldenText(
+      self.RemoveRedundantZeros(
+          text_format.MessageToString(message, as_one_line=True)),
+      'repeated_int64: -9223372036854775808'
+      ' repeated_uint64: 18446744073709551615'
+      ' repeated_double: 123.456'
+      ' repeated_double: 1.23e+22'
+      ' repeated_double: 1.23e-18'
+      ' repeated_string: '
+      '"\\000\\001\\007\\010\\014\\n\\r\\t\\013\\\\\\\'\\""'
+      ' repeated_string: "\\303\\274\\352\\234\\237"')
+
+  def testRoundTripExoticAsOneLine(self):
+    message = unittest_pb2.TestAllTypes()
+    message.repeated_int64.append(-9223372036854775808)
+    message.repeated_uint64.append(18446744073709551615)
+    message.repeated_double.append(123.456)
+    message.repeated_double.append(1.23e22)
+    message.repeated_double.append(1.23e-18)
+    message.repeated_string.append('\000\001\a\b\f\n\r\t\v\\\'"')
+    message.repeated_string.append(u'\u00fc\ua71f')
+
+    wire_text = text_format.MessageToString(message, as_one_line=True)
+    parsed_message = unittest_pb2.TestAllTypes()
+    text_format.Merge(wire_text, parsed_message)
+    self.assertEquals(message, parsed_message)
+
+  def testPrintRawUtf8String(self):
+    message = unittest_pb2.TestAllTypes()
+    message.repeated_string.append(u'\u00fc\ua71f')
+    self.CompareToGoldenText(
+        text_format.MessageToString(message, as_utf8 = True),
+        'repeated_string: "\303\274\352\234\237"\n')
 
   def testMessageToString(self):
     message = unittest_pb2.ForeignMessage()
@@ -119,8 +209,12 @@ class TextFormatTest(unittest.TestCase):
   def RemoveRedundantZeros(self, text):
     # Some platforms print 1e+5 as 1e+005.  This is fine, but we need to remove
     # these zeros in order to match the golden file.
-    return text.replace('e+0','e+').replace('e+0','e+') \
+    text = text.replace('e+0','e+').replace('e+0','e+') \
                .replace('e-0','e-').replace('e-0','e-')
+    # Floating point fields are printed with .0 suffix even if they are
+    # actualy integer numbers.
+    text = re.compile('\.0$', re.MULTILINE).sub('', text)
+    return text
 
   def testMergeGolden(self):
     golden_text = '\n'.join(self.ReadGolden('text_format_unittest_data.txt'))
@@ -191,8 +285,11 @@ class TextFormatTest(unittest.TestCase):
             'repeated_double: 1.23e+22\n'
             'repeated_double: 1.23e-18\n'
             'repeated_string: \n'
-            '\"\\000\\001\\007\\010\\014\\n\\r\\t\\013\\\\\\\'\\\"\"\n'
-            'repeated_string: "foo" \'corge\' "grault"')
+            '"\\000\\001\\007\\010\\014\\n\\r\\t\\013\\\\\\\'\\""\n'
+            'repeated_string: "foo" \'corge\' "grault"\n'
+            'repeated_string: "\\303\\274\\352\\234\\237"\n'
+            'repeated_string: "\\xc3\\xbc"\n'
+            'repeated_string: "\xc3\xbc"\n')
     text_format.Merge(text, message)
 
     self.assertEqual(-9223372036854775808, message.repeated_int64[0])
@@ -201,8 +298,30 @@ class TextFormatTest(unittest.TestCase):
     self.assertEqual(1.23e22, message.repeated_double[1])
     self.assertEqual(1.23e-18, message.repeated_double[2])
     self.assertEqual(
-        '\000\001\a\b\f\n\r\t\v\\\'\"', message.repeated_string[0])
+        '\000\001\a\b\f\n\r\t\v\\\'"', message.repeated_string[0])
     self.assertEqual('foocorgegrault', message.repeated_string[1])
+    self.assertEqual(u'\u00fc\ua71f', message.repeated_string[2])
+    self.assertEqual(u'\u00fc', message.repeated_string[3])
+
+  def testMergeEmptyText(self):
+    message = unittest_pb2.TestAllTypes()
+    text = ''
+    text_format.Merge(text, message)
+    self.assertEquals(unittest_pb2.TestAllTypes(), message)
+
+  def testMergeInvalidUtf8(self):
+    message = unittest_pb2.TestAllTypes()
+    text = 'repeated_string: "\\xc3\\xc3"'
+    self.assertRaises(text_format.ParseError, text_format.Merge, text, message)
+
+  def testMergeSingleWord(self):
+    message = unittest_pb2.TestAllTypes()
+    text = 'foo'
+    self.assertRaisesWithMessage(
+        text_format.ParseError,
+        ('1:1 : Message type "protobuf_unittest.TestAllTypes" has no field named '
+         '"foo".'),
+        text_format.Merge, text, message)
 
   def testMergeUnknownField(self):
     message = unittest_pb2.TestAllTypes()
@@ -297,7 +416,8 @@ class TokenizerTest(unittest.TestCase):
             'identifiER_4 : 1.1e+2 ID5:-0.23 ID6:\'aaaa\\\'bbbb\'\n'
             'ID7 : "aa\\"bb"\n\n\n\n ID8: {A:inf B:-inf C:true D:false}\n'
             'ID9: 22 ID10: -111111111111111111 ID11: -22\n'
-            'ID12: 2222222222222222222')
+            'ID12: 2222222222222222222 '
+            'false_bool:  0 true_BOOL:t \n true_bool1:  1 false_BOOL1:f ' )
     tokenizer = text_format._Tokenizer(text)
     methods = [(tokenizer.ConsumeIdentifier, 'identifier1'),
                ':',
@@ -347,7 +467,19 @@ class TokenizerTest(unittest.TestCase):
                (tokenizer.ConsumeInt32, -22),
                (tokenizer.ConsumeIdentifier, 'ID12'),
                ':',
-               (tokenizer.ConsumeUint64, 2222222222222222222)]
+               (tokenizer.ConsumeUint64, 2222222222222222222),
+               (tokenizer.ConsumeIdentifier, 'false_bool'),
+               ':',
+               (tokenizer.ConsumeBool, False),
+               (tokenizer.ConsumeIdentifier, 'true_BOOL'),
+               ':',
+               (tokenizer.ConsumeBool, True),
+               (tokenizer.ConsumeIdentifier, 'true_bool1'),
+               ':',
+               (tokenizer.ConsumeBool, True),
+               (tokenizer.ConsumeIdentifier, 'false_BOOL1'),
+               ':',
+               (tokenizer.ConsumeBool, False)]
 
     i = 0
     while not tokenizer.AtEnd():