From 63c55e048888397a3b163762e919256e4fe1f2da Mon Sep 17 00:00:00 2001
From: Richard Peters <richard.peters@philips.com>
Date: Tue, 9 Jul 2024 09:47:55 +0200
Subject: [PATCH] fix(echo): support serializing nested messages (#670)

* fix(echo): support serializing nested messages

* Apply suggestions from code review

Co-authored-by: Daan Timmer <8293597+daantimmer@users.noreply.github.com>

* Update protobuf/echo/ProtoMessageSender.hpp

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

---------

Co-authored-by: Daan Timmer <8293597+daantimmer@users.noreply.github.com>
Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
---
 infra/util/BoundedString.hpp                  | 2 +-
 protobuf/echo/ProtoMessageSender.hpp          | 3 ++-
 protobuf/echo/test/TestMessages.proto         | 5 +++++
 protobuf/echo/test/TestProtoMessageSender.cpp | 8 ++++++++
 4 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/infra/util/BoundedString.hpp b/infra/util/BoundedString.hpp
index 9263d49c9..fd1d6417a 100644
--- a/infra/util/BoundedString.hpp
+++ b/infra/util/BoundedString.hpp
@@ -1423,7 +1423,7 @@ namespace infra
         for (; additional != 0; --additional)
             range[index++] = *first++;
 
-        return &range[index];
+        return std::next(range.begin(), index);
     }
 
     template<class T>
diff --git a/protobuf/echo/ProtoMessageSender.hpp b/protobuf/echo/ProtoMessageSender.hpp
index 2297fc31c..7d68bc0b0 100644
--- a/protobuf/echo/ProtoMessageSender.hpp
+++ b/protobuf/echo/ProtoMessageSender.hpp
@@ -117,7 +117,8 @@ namespace services
     template<class Message>
     bool ProtoMessageSenderBase::SerializeField(ProtoMessage<Message>, infra::ProtoFormatter& formatter, const Message& value, uint32_t fieldNumber, bool& retry) const
     {
-        infra::DataOutputStream::WithWriter<infra::CountingStreamWriter> countingStream;
+        std::array<uint8_t, 16> saveStateStorage; // For writing length fields
+        infra::DataOutputStream::WithWriter<infra::CountingStreamWriter> countingStream{ saveStateStorage };
         infra::ProtoFormatter countingFormatter{ countingStream };
         value.Serialize(countingFormatter);
         formatter.PutLengthDelimitedSize(countingStream.Writer().Processed(), fieldNumber);
diff --git a/protobuf/echo/test/TestMessages.proto b/protobuf/echo/test/TestMessages.proto
index 57f243d02..a9e213914 100644
--- a/protobuf/echo/test/TestMessages.proto
+++ b/protobuf/echo/test/TestMessages.proto
@@ -163,6 +163,11 @@ message TestMoreNestedMessage
     NestedMessage2 message2 = 2;
 }
 
+message TestDeepNestedMessage
+{
+    TestNestedMessage message = 1;
+}
+
 message TestNestedRepeatedMessage
 {
     message NestedMessage
diff --git a/protobuf/echo/test/TestProtoMessageSender.cpp b/protobuf/echo/test/TestProtoMessageSender.cpp
index 46a51a08a..8d0eb8e03 100644
--- a/protobuf/echo/test/TestProtoMessageSender.cpp
+++ b/protobuf/echo/test/TestProtoMessageSender.cpp
@@ -176,6 +176,14 @@ TEST_F(ProtoMessageSenderTest, format_more_nested_message)
     ExpectFill({ (1 << 3) | 2, 2, 1 << 3, 5, (2 << 3) | 2, 2, 2 << 3, 10 }, sender);
 }
 
+TEST_F(ProtoMessageSenderTest, format_deep_nested_message)
+{
+    test_messages::TestDeepNestedMessage message{ { 5 } };
+    services::ProtoMessageSender sender{ message };
+
+    ExpectFill({ 1 << 3 | 2, 4, 1 << 3 | 2, 2, 1 << 3, 5 }, sender);
+}
+
 TEST_F(ProtoMessageSenderTest, dont_format_on_buffer_full)
 {
     test_messages::TestBoolWithBytes message;