Revert "third_party/protobuf: Update to HEAD (83d681ee2c)"

third_party/protobuf/python/google/protobuf/internal/python_message.py

Index: third_party/protobuf/python/google/protobuf/internal/python_message.py
diff --git a/third_party/protobuf/python/google/protobuf/internal/python_message.py b/third_party/protobuf/python/google/protobuf/internal/python_message.py
index c1bd1f9c3bde805d926f70a40e4fc70f6d8cb217..f8f73dd20486fb83c5576aea8e8ab7528b2eb25a 100755
--- a/third_party/protobuf/python/google/protobuf/internal/python_message.py
+++ b/third_party/protobuf/python/google/protobuf/internal/python_message.py
@@ -51,8 +51,8 @@ this file*.
 __author__ = 'robinson@google.com (Will Robinson)'
 
 from io import BytesIO
-import struct
 import sys
+import struct
 import weakref
 
 import six
@@ -63,10 +63,7 @@ except ImportError:
   # nothing like hermetic Python. This means lesser control on the system and
   # the six.moves package may be missing (is missing on 20150321 on gMac). Be
   # extra conservative and try to load the old replacement if it fails.
-  try:
-    import copy_reg as copyreg  #PY26
-  except ImportError:
-    import copyreg
+  import copy_reg as copyreg
 
 # We use "as" to avoid name collisions with variables.
 from google.protobuf.internal import containers
@@ -79,6 +76,7 @@ from google.protobuf.internal import well_known_types
 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 symbol_database
 from google.protobuf import text_format
 
 _FieldDescriptor = descriptor_mod.FieldDescriptor
@@ -100,12 +98,16 @@ class GeneratedProtocolMessageType(type):
   classes at runtime, as in this example:
 
   mydescriptor = Descriptor(.....)
-  factory = symbol_database.Default()
-  factory.pool.AddDescriptor(mydescriptor)
-  MyProtoClass = factory.GetPrototype(mydescriptor)
+  class MyProtoClass(Message):
+    __metaclass__ = GeneratedProtocolMessageType
+    DESCRIPTOR = mydescriptor
   myproto_instance = MyProtoClass()
   myproto.foo_field = 23
   ...
+
+  The above example will not work for nested types. If you wish to include them,
+  use reflection.MakeClass() instead of manually instantiating the class in
+  order to create the appropriate class structure.
   """
 
   # Must be consistent with the protocol-compiler code in
@@ -162,10 +164,12 @@ class GeneratedProtocolMessageType(type):
     """
     descriptor = dictionary[GeneratedProtocolMessageType._DESCRIPTOR_KEY]
     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(descriptor), None)
+          decoder.MessageSetItemDecoder(cls._extensions_by_number), None)
 
     # Attach stuff to each FieldDescriptor for quick lookup later on.
     for field in descriptor.fields:
@@ -381,15 +385,13 @@ def _GetInitializeDefaultForMap(field):
   if _IsMessageMapField(field):
     def MakeMessageMapDefault(message):
       return containers.MessageMap(
-          message._listener_for_children, value_field.message_type, key_checker,
-          field.message_type)
+          message._listener_for_children, value_field.message_type, key_checker)
     return MakeMessageMapDefault
   else:
     value_checker = type_checkers.GetTypeChecker(value_field)
     def MakePrimitiveMapDefault(message):
       return containers.ScalarMap(
-          message._listener_for_children, key_checker, value_checker,
-          field.message_type)
+          message._listener_for_children, key_checker, value_checker)
     return MakePrimitiveMapDefault
 
 def _DefaultValueConstructorForField(field):
@@ -745,21 +747,32 @@ def _AddPropertiesForExtensions(descriptor, cls):
     constant_name = extension_name.upper() + "_FIELD_NUMBER"
     setattr(cls, constant_name, extension_field.number)
 
-  # TODO(amauryfa): Migrate all users of these attributes to functions like
-  #   pool.FindExtensionByNumber(descriptor).
-  if descriptor.file is not None:
-    # TODO(amauryfa): Use cls.MESSAGE_FACTORY.pool when available.
-    pool = descriptor.file.pool
-    cls._extensions_by_number = pool._extensions_by_number[descriptor]
-    cls._extensions_by_name = pool._extensions_by_name[descriptor]
 
 def _AddStaticMethods(cls):
   # TODO(robinson): This probably needs to be thread-safe(?)
   def RegisterExtension(extension_handle):
     extension_handle.containing_type = cls.DESCRIPTOR
-    # TODO(amauryfa): Use cls.MESSAGE_FACTORY.pool when available.
-    cls.DESCRIPTOR.file.pool.AddExtensionDescriptor(extension_handle)
     _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):
@@ -913,33 +926,26 @@ def _InternalUnpackAny(msg):
   Returns:
     The unpacked message.
   """
-  # TODO(amauryfa): Don't use the factory of generated messages.
-  # To make Any work with custom factories, use the message factory of the
-  # parent message.
-  # pylint: disable=g-import-not-at-top
-  from google.protobuf import symbol_database
-  factory = symbol_database.Default()
-
   type_url = msg.type_url
+  db = symbol_database.Default()
 
   if not type_url:
     return None
 
   # TODO(haberman): For now we just strip the hostname.  Better logic will be
   # required.
-  type_name = type_url.split('/')[-1]
-  descriptor = factory.pool.FindMessageTypeByName(type_name)
+  type_name = type_url.split("/")[-1]
+  descriptor = db.pool.FindMessageTypeByName(type_name)
 
   if descriptor is None:
     return None
 
-  message_class = factory.GetPrototype(descriptor)
+  message_class = db.GetPrototype(descriptor)
   message = message_class()
 
   message.ParseFromString(msg.value)
   return message
 
-
 def _AddEqualsMethod(message_descriptor, cls):
   """Helper for _AddMessageMethods()."""
   def __eq__(self, other):
@@ -1217,7 +1223,7 @@ def _AddMergeFromMethod(cls):
     if not isinstance(msg, cls):
       raise TypeError(
           "Parameter to MergeFrom() must be instance of same class: "
-          'expected %s got %s.' % (cls.__name__, msg.__class__.__name__))
+          "expected %s got %s." % (cls.__name__, type(msg).__name__))
 
     assert msg is not self
     self._Modified()