From 6343c43d05a6176a7569c3159497d4a0a8a645a7 Mon Sep 17 00:00:00 2001
From: Azat Khuzhin <a3at.mail@gmail.com>
Date: Sun, 25 May 2025 18:24:48 +0200
Subject: [PATCH] Fix crash in get_member_id() if client group is not
 initialized

Since in this case rd_kafka_memberid() return NULL, and std::string
cannot be constructed from NULL [1].

  [1]: https://github.com/llvm/llvm-project/blob/fe51d8ae5772626ef8237c33e0911695cf4f07db/libcxx/include/string#L1051-L1055
---
 src/consumer.cpp | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/consumer.cpp b/src/consumer.cpp
index a244c370..c328ab28 100644
--- a/src/consumer.cpp
+++ b/src/consumer.cpp
@@ -241,6 +241,8 @@ TopicPartitionList Consumer::get_assignment() const {
 
 string Consumer::get_member_id() const {
     char* memberid_ptr = rd_kafka_memberid(get_handle());
+    if (memberid_ptr == nullptr)
+        return string();
     string memberid_string = memberid_ptr;
     rd_kafka_mem_free(nullptr, memberid_ptr);
     return memberid_string;