MDEV-37215 SELECT FOR UPDATE crash in SERIALIZABLE

ha_innobase::store_lock(): Set also trx->will_lock when starting
a transaction at SERIALIZABLE isolation level. This fixes up
commit 7fbbbc983f (MDEV-36330).

mysql-test/suite/innodb/r/lock_isolation.result

@@ -283,4 +283,13 @@ COMMIT;
 disconnect consistent;
 connection default;
 DROP TABLE t1,t2;
+#
+# MDEV-37215 SELECT...FOR UPDATE crash under SERIALIZABLE
+#
+SET SESSION TRANSACTION ISOLATION LEVEL SERIALIZABLE;
+CREATE TABLE t1(a INT PRIMARY KEY) ENGINE=InnoDB;
+SELECT * FROM t1 FOR UPDATE;
+a
+DROP TABLE t1;
+SET SESSION TRANSACTION ISOLATION LEVEL REPEATABLE READ;
 # End of 10.6 tests

mysql-test/suite/innodb/t/lock_isolation.test

@@ -295,5 +295,15 @@ COMMIT;
 --connection default
 DROP TABLE t1,t2;
 
+--echo #
+--echo # MDEV-37215 SELECT...FOR UPDATE crash under SERIALIZABLE
+--echo #
+
+SET SESSION TRANSACTION ISOLATION LEVEL SERIALIZABLE;
+CREATE TABLE t1(a INT PRIMARY KEY) ENGINE=InnoDB;
+SELECT * FROM t1 FOR UPDATE;
+DROP TABLE t1;
+SET SESSION TRANSACTION ISOLATION LEVEL REPEATABLE READ;
+
 --source include/wait_until_count_sessions.inc
 --echo # End of 10.6 tests

storage/innobase/handler/ha_innodb.cc

@@ -16510,6 +16510,7 @@ ha_innobase::store_lock(
 		case ISO_SERIALIZABLE:
 			auto trx_state = trx->state;
 			if (trx_state == TRX_STATE_NOT_STARTED) {
+				trx->will_lock = true;
 				trx_start_if_not_started(trx, false);
 				trx->read_view.open(trx);
 			} else {