Down integrate from Google internal.

Change-Id: I34d301133eea9c6f3a822c47d1f91e136fd33145

1 files changed, 58 insertions, 23 deletions

diff --git a/python/google/protobuf/internal/python_message.py b/python/google/protobuf/internal/python_message.py
index 6fda6ae0..6ad0f90d 100755
--- a/python/google/protobuf/internal/python_message.py
+++ b/python/google/protobuf/internal/python_message.py
@@ -219,12 +219,20 @@ def _AttachFieldHelpers(cls, 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),
-        field_descriptor if field_descriptor.containing_oneof is not None
-        else None)
+    decode_type = field_descriptor.type
+    if (decode_type == _FieldDescriptor.TYPE_ENUM and
+        type_checkers.SupportsOpenEnums(field_descriptor)):
+      decode_type = _FieldDescriptor.TYPE_INT32
+
+    oneof_descriptor = None
+    if field_descriptor.containing_oneof is not None:
+      oneof_descriptor = field_descriptor
+
+    field_decoder = type_checkers.TYPE_TO_DECODER[decode_type](
+        field_descriptor.number, is_repeated, is_packed,
+        field_descriptor, field_descriptor._default_constructor)
+
+    cls._decoders_by_tag[tag_bytes] = (field_decoder, oneof_descriptor)
 
   AddDecoder(type_checkers.FIELD_TYPE_TO_WIRE_TYPE[field_descriptor.type],
              False)
@@ -296,6 +304,8 @@ def _DefaultValueConstructorForField(field):
     def MakeSubMessageDefault(message):
       result = message_type._concrete_class()
       result._SetListener(message._listener_for_children)
+      if field.containing_oneof:
+        message._UpdateOneofState(field)
       return result
     return MakeSubMessageDefault
 
@@ -476,6 +486,7 @@ def _AddPropertiesForNonRepeatedScalarField(field, cls):
   type_checker = type_checkers.GetTypeChecker(field)
   default_value = field.default_value
   valid_values = set()
+  is_proto3 = field.containing_type.syntax == "proto3"
 
   def getter(self):
     # TODO(protobuf-team): This may be broken since there may not be
@@ -483,15 +494,24 @@ def _AddPropertiesForNonRepeatedScalarField(field, cls):
     return self._fields.get(field, default_value)
   getter.__module__ = None
   getter.__doc__ = 'Getter for %s.' % proto_field_name
+
+  clear_when_set_to_default = is_proto3 and not field.containing_oneof
+
   def field_setter(self, new_value):
     # pylint: disable=protected-access
-    self._fields[field] = type_checker.CheckValue(new_value)
+    # Testing the value for truthiness captures all of the proto3 defaults
+    # (0, 0.0, enum 0, and False).
+    new_value = type_checker.CheckValue(new_value)
+    if clear_when_set_to_default and not new_value:
+      self._fields.pop(field, None)
+    else:
+      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()
 
-  if field.containing_oneof is not None:
+  if field.containing_oneof:
     def setter(self, new_value):
       field_setter(self, new_value)
       self._UpdateOneofState(field)
@@ -624,24 +644,35 @@ def _AddListFieldsMethod(message_descriptor, cls):
 
   cls.ListFields = ListFields
 
+_Proto3HasError = 'Protocol message has no non-repeated submessage field "%s"'
+_Proto2HasError = 'Protocol message has no non-repeated field "%s"'
 
 def _AddHasFieldMethod(message_descriptor, cls):
   """Helper for _AddMessageMethods()."""
 
-  singular_fields = {}
+  is_proto3 = (message_descriptor.syntax == "proto3")
+  error_msg = _Proto3HasError if is_proto3 else _Proto2HasError
+
+  hassable_fields = {}
   for field in message_descriptor.fields:
-    if field.label != _FieldDescriptor.LABEL_REPEATED:
-      singular_fields[field.name] = field
-  # Fields inside oneofs are never repeated (enforced by the compiler).
-  for field in message_descriptor.oneofs:
-    singular_fields[field.name] = field
+    if field.label == _FieldDescriptor.LABEL_REPEATED:
+      continue
+    # For proto3, only submessages and fields inside a oneof have presence.
+    if (is_proto3 and field.cpp_type != _FieldDescriptor.CPPTYPE_MESSAGE and
+        not field.containing_oneof):
+      continue
+    hassable_fields[field.name] = field
+
+  if not is_proto3:
+    # Fields inside oneofs are never repeated (enforced by the compiler).
+    for oneof in message_descriptor.oneofs:
+      hassable_fields[oneof.name] = oneof
 
   def HasField(self, field_name):
     try:
-      field = singular_fields[field_name]
+      field = hassable_fields[field_name]
     except KeyError:
-      raise ValueError(
-          'Protocol message has no singular "%s" field.' % field_name)
+      raise ValueError(error_msg % field_name)
 
     if isinstance(field, descriptor_mod.OneofDescriptor):
       try:
@@ -871,6 +902,7 @@ def _AddMergeFromStringMethod(message_descriptor, cls):
   local_ReadTag = decoder.ReadTag
   local_SkipField = decoder.SkipField
   decoders_by_tag = cls._decoders_by_tag
+  is_proto3 = message_descriptor.syntax == "proto3"
 
   def InternalParse(self, buffer, pos, end):
     self._Modified()
@@ -884,9 +916,11 @@ def _AddMergeFromStringMethod(message_descriptor, cls):
         new_pos = local_SkipField(buffer, new_pos, end, tag_bytes)
         if new_pos == -1:
           return pos
-        if not unknown_field_list:
-          unknown_field_list = self._unknown_fields = []
-        unknown_field_list.append((tag_bytes, buffer[value_start_pos:new_pos]))
+        if not is_proto3:
+          if not unknown_field_list:
+            unknown_field_list = self._unknown_fields = []
+          unknown_field_list.append(
+              (tag_bytes, buffer[value_start_pos:new_pos]))
         pos = new_pos
       else:
         pos = field_decoder(buffer, new_pos, end, self, field_dict)
@@ -1008,6 +1042,8 @@ def _AddMergeFromMethod(cls):
             # Construct a new object to represent this field.
             field_value = field._default_constructor(self)
             fields[field] = field_value
+            if field.containing_oneof:
+              self._UpdateOneofState(field)
           field_value.MergeFrom(value)
       else:
         self._fields[field] = value
@@ -1252,11 +1288,10 @@ class _ExtensionDict(object):
 
     # 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)
+    type_checker = type_checkers.GetTypeChecker(extension_handle)
     # pylint: disable=protected-access
     self._extended_message._fields[extension_handle] = (
-      type_checker.CheckValue(value))
+        type_checker.CheckValue(value))
     self._extended_message._Modified()
 
   def _FindExtensionByName(self, name):