From 598d772be566cc080bf9d0538c847cd28591de42 Mon Sep 17 00:00:00 2001
From: "Ralf W. Grosse-Kunstleve" <rwgk@google.com>
Date: Sun, 4 Feb 2024 11:30:58 -0800
Subject: [PATCH] `LOG(WARNING)` `FALL BACK TO PROTOBUF SERIALIZE/PARSE` based
 on `ExtensionsWithUnknownFieldsPolicy`.

PiperOrigin-RevId: 604127759
---
 pybind11_protobuf/BUILD                   |  2 +-
 pybind11_protobuf/check_unknown_fields.cc |  5 +----
 pybind11_protobuf/check_unknown_fields.h  |  2 +-
 pybind11_protobuf/proto_cast_util.cc      | 14 +++++++++-----
 4 files changed, 12 insertions(+), 11 deletions(-)

diff --git a/pybind11_protobuf/BUILD b/pybind11_protobuf/BUILD
index deba58a..bd63d58 100644
--- a/pybind11_protobuf/BUILD
+++ b/pybind11_protobuf/BUILD
@@ -88,7 +88,7 @@ cc_library(
     srcs = ["check_unknown_fields.cc"],
     hdrs = ["check_unknown_fields.h"],
     visibility = [
-        "//visibility:private",
+        "//third_party/clif/python:__pkg__",
     ],
     deps = [
         "@com_google_absl//absl/container:flat_hash_map",
diff --git a/pybind11_protobuf/check_unknown_fields.cc b/pybind11_protobuf/check_unknown_fields.cc
index bb67d69..0639d09 100644
--- a/pybind11_protobuf/check_unknown_fields.cc
+++ b/pybind11_protobuf/check_unknown_fields.cc
@@ -183,7 +183,7 @@ void AllowUnknownFieldsFor(absl::string_view top_message_descriptor_full_name,
 
 std::optional<std::string> CheckRecursively(
     const ::google::protobuf::python::PyProto_API* py_proto_api,
-    const ::google::protobuf::Message* message, bool build_error_message_if_any) {
+    const ::google::protobuf::Message* message) {
   const auto* root_descriptor = message->GetDescriptor();
   HasUnknownFields search{py_proto_api, root_descriptor};
   if (!search.FindUnknownFieldsRecursive(message, 0u)) {
@@ -193,9 +193,6 @@ std::optional<std::string> CheckRecursively(
                                              search.FieldFQN())) != 0) {
     return std::nullopt;
   }
-  if (!build_error_message_if_any) {
-    return "";  // This indicates that an unknown field was found.
-  }
   return search.BuildErrorMessage();
 }
 
diff --git a/pybind11_protobuf/check_unknown_fields.h b/pybind11_protobuf/check_unknown_fields.h
index e37adc7..79ac001 100644
--- a/pybind11_protobuf/check_unknown_fields.h
+++ b/pybind11_protobuf/check_unknown_fields.h
@@ -47,7 +47,7 @@ void AllowUnknownFieldsFor(absl::string_view top_message_descriptor_full_name,
 
 std::optional<std::string> CheckRecursively(
     const ::google::protobuf::python::PyProto_API* py_proto_api,
-    const ::google::protobuf::Message* top_message, bool build_error_message_if_any);
+    const ::google::protobuf::Message* top_message);
 
 }  // namespace pybind11_protobuf::check_unknown_fields
 
diff --git a/pybind11_protobuf/proto_cast_util.cc b/pybind11_protobuf/proto_cast_util.cc
index 0f7ba29..064797a 100644
--- a/pybind11_protobuf/proto_cast_util.cc
+++ b/pybind11_protobuf/proto_cast_util.cc
@@ -9,6 +9,7 @@
 #include <iostream>
 #include <memory>
 #include <string>
+#include <unordered_set>
 #include <utility>
 #include <vector>
 
@@ -828,14 +829,17 @@ py::handle GenericProtoCast(Message* src, py::return_value_policy policy,
 
   std::optional<std::string> unknown_field_message =
       check_unknown_fields::CheckRecursively(
-          GlobalState::instance()->py_proto_api(), src,
-          check_unknown_fields::ExtensionsWithUnknownFieldsPolicy::
-              UnknownFieldsAreDisallowed());
+          GlobalState::instance()->py_proto_api(), src);
   if (unknown_field_message) {
-    if (!unknown_field_message->empty()) {
+    if (check_unknown_fields::ExtensionsWithUnknownFieldsPolicy::
+            UnknownFieldsAreDisallowed()) {
       throw py::value_error(*unknown_field_message);
     }
-    // Fall back to serialize/parse.
+    static auto fall_back_log_shown = new std::unordered_set<std::string>();
+    if (fall_back_log_shown->insert(*unknown_field_message).second) {
+      LOG(WARNING) << "FALL BACK TO PROTOBUF SERIALIZE/PARSE: "
+                   << *unknown_field_message;
+    }
     return GenericPyProtoCast(src, policy, parent, is_const);
   }