Merge branch '2.3' into 2.4

system-test/crash_on_bad_sescmd.cpp

@@ -0,0 +1,69 @@
+/**
+ * Double-close on bad session command result
+ */
+
+#include <maxtest/testconnections.hh>
+
+void run_test(TestConnections& test)
+{
+    Connection conn = test.maxscales->rwsplit();
+    conn.connect();
+
+    for (int i = 0; i <= 300 && test.global_result == 0; i++)
+    {
+        if (conn.query("SET @a = 1")
+            && conn.query("USE test")
+            && conn.query("SET SQL_MODE=''")
+            && conn.query("USE test")
+            && conn.query("SELECT @@last_insert_id")
+            && conn.query("SELECT 1")
+            && conn.query("USE test")
+            && conn.query("SELECT 1")
+            && conn.query("SET @a = 123")
+            && conn.query("BEGIN")
+            && conn.query("SELECT @a")
+            && conn.query("COMMIT")
+            && conn.query("SET @a = 321")
+            && conn.query("SELECT @a")
+            && conn.query("SET @a = 456")
+            && conn.query("START TRANSACTION READ ONLY")
+            && conn.query("SELECT @a")
+            && conn.query("COMMIT")
+            && conn.query("PREPARE ps FROM 'SELECT 1'")
+            && conn.query("EXECUTE ps")
+            && conn.query("DEALLOCATE PREPARE ps"))
+        {
+            conn.reset_connection();
+        }
+        else
+        {
+            break;
+        }
+    }
+}
+
+int main(int argc, char* argv[])
+{
+    TestConnections test(argc, argv);
+
+    std::vector<std::thread> threads;
+
+    for (int i = 0; i < 5; i++)
+    {
+        threads.emplace_back(run_test, std::ref(test));
+    }
+
+    for (int i = 0; i < 5; i++)
+    {
+        test.repl->stop_node(1 + i % 3);
+        test.repl->start_node(1 + i % 3);
+        sleep(1);
+    }
+
+    for (auto& a : threads)
+    {
+        a.join();
+    }
+
+    return test.global_result;
+}