From bcbee613e414f5449cd0ed3e722e35706db7cf28 Mon Sep 17 00:00:00 2001
From: mu <59917266+4eUeP@users.noreply.github.com>
Date: Mon, 22 Jan 2024 21:55:26 -0800
Subject: [PATCH] fix(kafka cpp): do not free NUL stable_ptr (#1747)

---
 hstream-kafka/cbits/hs_kafka_server.cpp | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/hstream-kafka/cbits/hs_kafka_server.cpp b/hstream-kafka/cbits/hs_kafka_server.cpp
index 290ad40c7..ddd8f102b 100644
--- a/hstream-kafka/cbits/hs_kafka_server.cpp
+++ b/hstream-kafka/cbits/hs_kafka_server.cpp
@@ -55,9 +55,12 @@ class ServerHandler : public HandlerAdapter<std::unique_ptr<folly::IOBuf>> {
   HsStablePtr sp_;
 
   void onClientExit() {
-    hs_free_stable_ptr(sp_);
-    // Make sure the haskell land does not use the freed stable pointer
-    sp_ = nullptr;
+    // FIXME: lock guard here?
+    if (sp_ != nullptr) {
+      hs_free_stable_ptr(sp_);
+      // Make sure the haskell land does not use the freed stable pointer
+      sp_ = nullptr;
+    }
   }
 };