MDEV-15970 Crash when doing truncate on locked sequence

Problem was that we used table->s->db_type() for accessing
handlerton of opened file instead of table->file->ht

Other bug fixed:
- Ensure that we set error if reopen_tables() fails
  (This was the cause of assert)

2 files changed, 17 insertions, 1 deletions

diff --git a/mysql-test/suite/sql_sequence/lock.result b/mysql-test/suite/sql_sequence/lock.result
index 92c75ff8188..e92bdbffcf9 100644
--- a/mysql-test/suite/sql_sequence/lock.result
+++ b/mysql-test/suite/sql_sequence/lock.result
@@ -32,3 +32,8 @@ CREATE SEQUENCE seq2;
 LOCK TABLE seq1 WRITE, seq2 WRITE;
 INSERT INTO seq1 VALUES (1, 1, 100000, 1, 1, 100, 1, 1);
 DROP SEQUENCE seq1, seq2;
+CREATE OR REPLACE SEQUENCE s1 ENGINE=MyISAM;
+LOCK TABLE s1 WRITE;
+TRUNCATE TABLE s1;
+ERROR HY000: Storage engine SEQUENCE of the table `test`.`s1` doesn't have this option
+DROP SEQUENCE s1;
diff --git a/mysql-test/suite/sql_sequence/lock.test b/mysql-test/suite/sql_sequence/lock.test
index 730404abf38..1cb6aa6fb54 100644
--- a/mysql-test/suite/sql_sequence/lock.test
+++ b/mysql-test/suite/sql_sequence/lock.test
@@ -39,7 +39,6 @@ DROP SEQUENCE s1;
 unlock tables;
 DROP SEQUENCE s1;
 
-
 #
 # MDEV-15106 Unexpected ER_WRONG_INSERT_INTO_SEQUENCE upon INSERT with
 # multiple locks on sequences
@@ -51,3 +50,15 @@ LOCK TABLE seq1 WRITE, seq2 WRITE;
 INSERT INTO seq1 VALUES (1, 1, 100000, 1, 1, 100, 1, 1);
 DROP SEQUENCE seq1, seq2;
 
+#
+# MDEV-15970
+# Assertion `!is_set() || (m_status == DA_OK_BULK && is_bulk_op())' failure and/or
+# ER_KEY_NOT_FOUND upon TRUNCATE sequence under lock
+#
+
+CREATE OR REPLACE SEQUENCE s1 ENGINE=MyISAM;
+LOCK TABLE s1 WRITE;
+--error ER_ILLEGAL_HA
+TRUNCATE TABLE s1;
+# Cleanup
+DROP SEQUENCE s1;