From 91e14de1f7c0a208fb0275bb18a4dd4191d757ad Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Cl=C3=A9ment=20P=C3=A9ron?= <peron.clem@gmail.com>
Date: Wed, 18 Jun 2025 18:05:38 +0200
Subject: [PATCH] ortools: utils: keep compatibility with protobuf < 26

---
 ortools/util/file_util.cc | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/ortools/util/file_util.cc b/ortools/util/file_util.cc
index 6ee86f6e52..62d0aaa314 100644
--- a/ortools/util/file_util.cc
+++ b/ortools/util/file_util.cc
@@ -166,7 +166,11 @@ absl::Status WriteProtoToFile(absl::string_view filename,
     case ProtoWriteFormat::kJson: {
       google::protobuf::util::JsonPrintOptions options;
       options.add_whitespace = true;
+#if PROTOBUF_VERSION >= 5026000  // Version 26.0.0
       options.always_print_fields_with_no_presence = true;
+#else
+      options.always_print_primitive_fields = true;
+#endif
       options.preserve_proto_field_names = true;
       if (!google::protobuf::util::MessageToJsonString(proto, &output_string,
                                                        options)