From 8eadf021021f8d869673c7ae5494aa71ab1a6c50 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Konstantin=20K=C3=A4fer?= <mail@kkaefer.com>
Date: Thu, 8 Oct 2026 11:25:30 +0200
Subject: [PATCH] Fix -Wsign-conversion warning in commit_submessage

---
 CHANGELOG.md                           | 2 ++
 include/protozero/basic_pbf_writer.hpp | 2 +-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1c3e8a95..5ec5e13e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -17,6 +17,8 @@ This project adheres to [Semantic Versioning](https://semver.org/).
 
 ### Fixed
 
+- Fix `-Wsign-conversion` warning in `basic_pbf_writer::commit_submessage()`.
+
 ## [1.8.2] - 2026-06-30
 
 ### Fixed
diff --git a/include/protozero/basic_pbf_writer.hpp b/include/protozero/basic_pbf_writer.hpp
index cc0f7cd5..9e0af4ea 100644
--- a/include/protozero/basic_pbf_writer.hpp
+++ b/include/protozero/basic_pbf_writer.hpp
@@ -204,7 +204,7 @@ class basic_pbf_writer {
         protozero_assert(buffer_customization<TBuffer>::size(m_data) >= m_pos - reserve_bytes);
         const auto n = add_varint_to_buffer(buffer_customization<TBuffer>::at_pos(m_data, m_pos - reserve_bytes), length);
 
-        buffer_customization<TBuffer>::erase_range(m_data, m_pos - reserve_bytes + n, m_pos);
+        buffer_customization<TBuffer>::erase_range(m_data, m_pos - reserve_bytes + static_cast<std::size_t>(n), m_pos);
         m_pos = 0;
     }