MXS-3220: Add test case

Added a test case that reproduces the crash which occurs when the history
replay fails.

system-test/CMakeLists.txt

@@ -938,6 +938,9 @@ add_test_executable(mxs2919_broken_slaves.cpp mxs2919_broken_slaves mxs2919_brok
 # MXS-2972: Caching of shards must take servers into notice
 add_test_executable(mxs2972_shard_caching.cc mxs2972_shard_caching mxs2972_shard_caching LABELS REPL_BACKEND schemarouter)
 
+# MXS-3220: Crash on master reconnection with session command
+add_test_executable(mxs3220_reconnect_crash.cc mxs3220_reconnect_crash mxs3220_reconnect_crash LABELS REPL_BACKEND readwritesplit)
+
 ############################################
 # END: Normal tests                        #
 ############################################

system-test/cnf/maxscale.cnf.template.mxs3220_reconnect_crash

@@ -0,0 +1,31 @@
+[maxscale]
+threads=###threads###
+
+[MySQL-Monitor]
+type=monitor
+module=mysqlmon
+servers=###server_line###
+user=maxskysql
+password=skysql
+monitor_interval=1000
+
+[RW-Split-Router]
+type=service
+router=readwritesplit
+servers=server1
+user=maxskysql
+password=skysql
+master_reconnection=true
+master_failure_mode=fail_on_write
+delayed_retry=true
+transaction_replay=true
+prune_sescmd_history=true
+use_sql_variables_in=master
+
+[RW-Split-Listener]
+type=listener
+service=RW-Split-Router
+protocol=MySQLClient
+port=4006
+
+###server###

system-test/mxs3220_reconnect_crash.cc

@@ -0,0 +1,50 @@
+/**
+ * MXS-3220: Crash when session command history execution fails
+ */
+
+#include <maxtest/testconnections.hh>
+
+int main(int argc, char** argv)
+{
+    TestConnections test(argc, argv);
+
+    auto conn = test.maxscales->rwsplit();
+    conn.connect();
+    conn.query("CREATE USER 'bob' IDENTIFIED BY 'bob'");
+    conn.query("GRANT ALL ON *.* TO 'bob'");
+    conn.disconnect();
+
+    conn.set_credentials("bob", "bob");
+    conn.connect();
+    conn.query("SET @a = (SELECT SLEEP(10))");
+
+    auto master = test.repl->get_connection(0);
+    master.connect();
+
+    // Kill the current master connection. With master_failure_mode=fail_on_write this will not
+    // close the connection.
+    master.query("SET @id = (SELECT id FROM information_schema.processlist WHERE user = 'bob')");
+    master.query("KILL @id");
+
+
+    // Start a thread that kills the master connection again in five seconds. This should give enough time for
+    // the reconnection and history replay to start.
+    std::thread thr([&]() {
+                        sleep(5);
+                        master.query(
+                            "SET @id = (SELECT id FROM information_schema.processlist WHERE user = 'bob')");
+                        master.query("KILL @id");
+                    });
+
+    // This triggers a reconnection and the execution of the session command history
+    test.expect(conn.query("SET @b = 1"), "Interrupted query should work: %s", conn.error());
+    auto res = conn.field("SELECT @b");
+    test.expect(!res.empty(), "User variable @b should not be empty");
+
+    thr.join();
+
+    conn.connect();
+    conn.query("DROP USER 'bob'");
+
+    return test.global_result;
+}