From 1e5a820be9810afe069c3acec9aad68da01597cd Mon Sep 17 00:00:00 2001
From: Alan Yu <alan.yu@timeplus.io>
Date: Wed, 11 Mar 2026 16:15:50 +0800
Subject: [PATCH 1/3] fix potential NPE

---
 .gitignore               | 6 ++++++
 timeplus/client_pool.cpp | 8 +++++---
 timeplus/client_pool.h   | 2 +-
 3 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/.gitignore b/.gitignore
index 8def154..e7105eb 100644
--- a/.gitignore
+++ b/.gitignore
@@ -278,3 +278,9 @@ BUCKAROO_DEPS
 # Vim
 *.swp
 *.swo
+
+# clangd
+.cache/
+
+# Claude Code
+.claude/settings.local.json
diff --git a/timeplus/client_pool.cpp b/timeplus/client_pool.cpp
index ec0649e..874c0fb 100644
--- a/timeplus/client_pool.cpp
+++ b/timeplus/client_pool.cpp
@@ -30,15 +30,17 @@ ClientPool::ClientPtr ClientPool::Acquire(int64_t timeout_ms) {
 }
 
 void ClientPool::GuardedClient::TestConnection() noexcept {
+    if (!client) {
+        valid = false;
+        return;
+    }
+
     try {
         client->Ping();
         valid = true;
     } catch (...) {
         valid = false;
     }
-
-    TRACE("test connection: host=%s port=%d valid=%s", client->GetCurrentEndpoint()->host.c_str(), client->GetCurrentEndpoint()->port,
-          valid ? "true" : "false");
 }
 
 }  // namespace timeplus
diff --git a/timeplus/client_pool.h b/timeplus/client_pool.h
index d687dbe..ddaa03b 100644
--- a/timeplus/client_pool.h
+++ b/timeplus/client_pool.h
@@ -36,7 +36,7 @@ class ClientPool {
         GuardedClient(ClientPool* pool, ClientPtr client, bool valid) : client(std::move(client)), valid(valid), pool_(pool) {}
 
         ~GuardedClient() {
-            if (pool_) {
+            if (pool_ && client) {
                 pool_->Release(std::move(client), valid);
             }
         }

From 6cf8b15cbbdbc0bfa936e06a1f0af3db229ab0ff Mon Sep 17 00:00:00 2001
From: Alan Yu <alan.yu@timeplus.io>
Date: Wed, 11 Mar 2026 17:43:31 +0800
Subject: [PATCH 2/3] better

---
 timeplus/client_pool.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/timeplus/client_pool.h b/timeplus/client_pool.h
index ddaa03b..5c982e1 100644
--- a/timeplus/client_pool.h
+++ b/timeplus/client_pool.h
@@ -36,7 +36,7 @@ class ClientPool {
         GuardedClient(ClientPool* pool, ClientPtr client, bool valid) : client(std::move(client)), valid(valid), pool_(pool) {}
 
         ~GuardedClient() {
-            if (pool_ && client) {
+            if (pool_) {
                 pool_->Release(std::move(client), valid);
             }
         }
@@ -47,7 +47,7 @@ class ClientPool {
 
         GuardedClient& operator=(GuardedClient&& other) noexcept {
             if (this != &other) {
-                if (pool_ && client) {
+                if (pool_) {
                     pool_->Release(std::move(client), valid);
                 }
                 pool_ = other.pool_;

From 5269d1fe35b6f9c9a1e753efa89f8c17f81e7514 Mon Sep 17 00:00:00 2001
From: yun <113408135+yokofly@users.noreply.github.com>
Date: Wed, 11 Mar 2026 02:51:07 -0700
Subject: [PATCH 3/3] Add ClientPool slot regression test

---
 ut/client_pool_ut.cpp | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/ut/client_pool_ut.cpp b/ut/client_pool_ut.cpp
index 6823a6e..839ce40 100644
--- a/ut/client_pool_ut.cpp
+++ b/ut/client_pool_ut.cpp
@@ -44,3 +44,18 @@ TEST(ClientPool, BadHost) {
 
     ASSERT_THROW(pool.Acquire(1000), std::system_error);
 }
+
+TEST(ClientPool, GuardedClientResetStillReturnsSlot) {
+    ClientOptions client_options;
+    client_options.host = "localhost";
+    ClientPool pool{client_options, /*pool_size=*/1};
+
+    {
+        auto guarded = pool.GetGuardedClient(1000);
+        ASSERT_NE(guarded.client, nullptr);
+        guarded.client.reset();
+    }
+
+    auto client = pool.Acquire(100);
+    ASSERT_NE(client, nullptr);
+}