MDEV-13982 Server crashes in in ha_partition::engine_name

use the correct handlerton when looking for TRANSACTIONAL=1 support

mysql-test/suite/parts/r/partition_alter_maria.result

@@ -16,6 +16,15 @@ select * from t1;
 pk	dt
 1	2017-09-28 15:12:00
 drop table t1;
+create table t1 (a int) engine=Aria transactional=1 partition by hash(a) partitions 2;
+show create table t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `a` int(11) DEFAULT NULL
+) ENGINE=Aria DEFAULT CHARSET=latin1 TRANSACTIONAL=1
+/*!50100 PARTITION BY HASH (a)
+PARTITIONS 2 */
+drop table t1;
 #
 # MDEV-13788 Server crash when issuing bad SQL partition syntax
 #

mysql-test/suite/parts/t/partition_alter_maria.test

@@ -17,5 +17,12 @@ alter table t1 drop partition p20181231;
 select * from t1;
 drop table t1;
 
+#
+# MDEV-13982 Server crashes in in ha_partition::engine_name
+#
+create table t1 (a int) engine=Aria transactional=1 partition by hash(a) partitions 2;
+show create table t1;
+drop table t1;
+
 --let $engine=Aria
 --source inc/part_alter_values.inc

sql/sql_table.cc

@@ -4397,7 +4397,7 @@ bool mysql_create_table_no_lock(THD *thd,
   /* Give warnings for not supported table options */
 #if defined(WITH_ARIA_STORAGE_ENGINE)
   extern handlerton *maria_hton;
-  if (file->ht != maria_hton)
+  if (file->partition_ht() != maria_hton)
 #endif
     if (create_info->transactional)
       push_warning_printf(thd, MYSQL_ERROR::WARN_LEVEL_WARN,