From 4ebba684c791416a9131dd01d4c5175a2beb3566 Mon Sep 17 00:00:00 2001
From: Jie Luo <jieluo@google.com>
Date: Fri, 5 Jan 2024 07:22:32 -0800
Subject: [PATCH] BREAKING CHANGE in v26: Remove RegisterExtension in message
 class

PiperOrigin-RevId: 595989309
---
 .../protobuf/internal/python_message.py       |  9 ------
 python/google/protobuf/message.py             |  5 ----
 python/google/protobuf/pyext/message.cc       | 28 -------------------
 python/google/protobuf/pyext/message.h        |  4 ---
 4 files changed, 46 deletions(-)

diff --git a/python/google/protobuf/internal/python_message.py b/python/google/protobuf/internal/python_message.py
index 870ff185f09b8..e9e5cd5e40ebc 100755
--- a/python/google/protobuf/internal/python_message.py
+++ b/python/google/protobuf/internal/python_message.py
@@ -779,15 +779,6 @@ def _AddPropertiesForExtensions(descriptor, cls):
     pool = descriptor.file.pool
 
 def _AddStaticMethods(cls):
-  # TODO: This probably needs to be thread-safe(?)
-  def RegisterExtension(field_descriptor):
-    field_descriptor.containing_type = cls.DESCRIPTOR
-    # TODO: Use cls.MESSAGE_FACTORY.pool when available.
-    # pylint: disable=protected-access
-    cls.DESCRIPTOR.file.pool._AddExtensionDescriptor(field_descriptor)
-    _AttachFieldHelpers(cls, field_descriptor)
-  cls.RegisterExtension = staticmethod(RegisterExtension)
-
   def FromString(s):
     message = cls()
     message.MergeFromString(s)
diff --git a/python/google/protobuf/message.py b/python/google/protobuf/message.py
index 29ebd7b0e2e7c..3226b6e776cef 100755
--- a/python/google/protobuf/message.py
+++ b/python/google/protobuf/message.py
@@ -340,11 +340,6 @@ def ByteSize(self):
   def FromString(cls, s):
     raise NotImplementedError
 
-# TODO: Remove it in OSS
-  @staticmethod
-  def RegisterExtension(field_descriptor):
-    raise NotImplementedError
-
   def _SetListener(self, message_listener):
     """Internal method used by the protocol message implementation.
     Clients should not call this directly.
diff --git a/python/google/protobuf/pyext/message.cc b/python/google/protobuf/pyext/message.cc
index 7e01f64ae8781..42bb20da042da 100644
--- a/python/google/protobuf/pyext/message.cc
+++ b/python/google/protobuf/pyext/message.cc
@@ -1855,32 +1855,6 @@ static PyObject* ByteSize(CMessage* self, PyObject* args) {
   return PyLong_FromLong(self->message->ByteSizeLong());
 }
 
-PyObject* RegisterExtension(PyObject* cls, PyObject* extension_handle) {
-  const FieldDescriptor* descriptor =
-      GetExtensionDescriptor(extension_handle);
-  if (descriptor == nullptr) {
-    return nullptr;
-  }
-  if (!PyObject_TypeCheck(cls, CMessageClass_Type)) {
-    PyErr_Format(PyExc_TypeError, "Expected a message class, got %s",
-                 cls->ob_type->tp_name);
-    return nullptr;
-  }
-  CMessageClass *message_class = reinterpret_cast<CMessageClass*>(cls);
-  if (message_class == nullptr) {
-    return nullptr;
-  }
-  // If the extension was already registered, check that it is the same.
-  const FieldDescriptor* existing_extension =
-      message_class->py_message_factory->pool->pool->FindExtensionByNumber(
-          descriptor->containing_type(), descriptor->number());
-  if (existing_extension != nullptr && existing_extension != descriptor) {
-    PyErr_SetString(PyExc_ValueError, "Double registration of Extensions");
-    return nullptr;
-  }
-  Py_RETURN_NONE;
-}
-
 static PyObject* SetInParent(CMessage* self, PyObject* args) {
   AssureWritable(self);
   Py_RETURN_NONE;
@@ -2391,8 +2365,6 @@ static PyMethodDef Methods[] = {
      "Merges a serialized message into the current message."},
     {"ParseFromString", (PyCFunction)ParseFromString, METH_O,
      "Parses a serialized message into the current message."},
-    {"RegisterExtension", (PyCFunction)RegisterExtension, METH_O | METH_CLASS,
-     "Registers an extension with the current message."},
     {"SerializePartialToString", (PyCFunction)SerializePartialToString,
      METH_VARARGS | METH_KEYWORDS,
      "Serializes the message to a string, even if it isn't initialized."},
diff --git a/python/google/protobuf/pyext/message.h b/python/google/protobuf/pyext/message.h
index 3d1336b860bdf..dc5018227a296 100644
--- a/python/google/protobuf/pyext/message.h
+++ b/python/google/protobuf/pyext/message.h
@@ -229,10 +229,6 @@ int InitAttributes(CMessage* self, PyObject* args, PyObject* kwargs);
 
 PyObject* MergeFrom(CMessage* self, PyObject* arg);
 
-// This method does not do anything beyond checking that no other extension
-// has been registered with the same field number on this class.
-PyObject* RegisterExtension(PyObject* cls, PyObject* extension_handle);
-
 // Get a field from a message.
 PyObject* GetFieldValue(CMessage* self,
                         const FieldDescriptor* field_descriptor);