From eb2f0fd6d8a6489fbb147692da6e3ef580fcb2b0 Mon Sep 17 00:00:00 2001
From: Sutou Kouhei <kou@clear-code.com>
Date: Mon, 5 Jan 2026 16:20:28 +0900
Subject: [PATCH] GH-48725: [C++] Fix bundled Protobuf doesn't exist in
 libarrow_bundled_dependencies

---
 cpp/cmake_modules/ThirdpartyToolchain.cmake | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/cpp/cmake_modules/ThirdpartyToolchain.cmake b/cpp/cmake_modules/ThirdpartyToolchain.cmake
index 8a26b46d0bf..42fa5e34b3c 100644
--- a/cpp/cmake_modules/ThirdpartyToolchain.cmake
+++ b/cpp/cmake_modules/ThirdpartyToolchain.cmake
@@ -1974,7 +1974,9 @@ function(build_protobuf)
 
   # Make protobuf_fc depend on the install completion marker
   add_custom_target(protobuf_fc DEPENDS "${PROTOBUF_PREFIX}/.protobuf_installed")
-  list(APPEND ARROW_BUNDLED_STATIC_LIBS protobuf::libprotobuf)
+  set(ARROW_BUNDLED_STATIC_LIBS
+      ${ARROW_BUNDLED_STATIC_LIBS} protobuf::libprotobuf
+      PARENT_SCOPE)
 
   if(CMAKE_CROSSCOMPILING)
     # If we are cross compiling, we need to build protoc for the host