From 0bfd45f63419c45b68448cbd210a6e73e5c1ab34 Mon Sep 17 00:00:00 2001
From: Monty <monty@mariadb.org>
Date: Sun, 6 May 2018 19:39:48 +0300
Subject: [PATCH] Fix for MDEV-15812 Assert in SEQUENCE when forcing STATEMEMT
 format

The bug was the we copied the lock type to the underlying engine even when
external_lock failed.
---
 .../suite/sql_sequence/replication_drop.result  |  5 +++++
 .../suite/sql_sequence/replication_drop.test    | 17 +++++++++++++++++
 sql/ha_sequence.cc                              |  3 ++-
 3 files changed, 24 insertions(+), 1 deletion(-)
 create mode 100644 mysql-test/suite/sql_sequence/replication_drop.result
 create mode 100644 mysql-test/suite/sql_sequence/replication_drop.test

diff --git a/mysql-test/suite/sql_sequence/replication_drop.result b/mysql-test/suite/sql_sequence/replication_drop.result
new file mode 100644
index 00000000000..1cd7022765e
--- /dev/null
+++ b/mysql-test/suite/sql_sequence/replication_drop.result
@@ -0,0 +1,5 @@
+CREATE SEQUENCE seq ENGINE=InnoDB;
+SET SESSION TRANSACTION ISOLATION LEVEL READ COMMITTED;
+INSERT INTO seq VALUES (1,1,100,1,1,1,1,1);
+ERROR HY000: Cannot execute statement: impossible to write to binary log since BINLOG_FORMAT = STATEMENT and at least one table uses a storage engine limited to row-based logging. InnoDB is limited to row-logging when transaction isolation level is READ COMMITTED or READ UNCOMMITTED.
+DROP SEQUENCE seq;
diff --git a/mysql-test/suite/sql_sequence/replication_drop.test b/mysql-test/suite/sql_sequence/replication_drop.test
new file mode 100644
index 00000000000..ca050246391
--- /dev/null
+++ b/mysql-test/suite/sql_sequence/replication_drop.test
@@ -0,0 +1,17 @@
+#
+# Test for MDEV-15812
+# Assertion `m_lock_type == 2' failed in
+# handler::~handler on dropping a sequence after
+# ER_BINLOG_STMT_MODE_AND_ROW_ENGINE
+#
+
+--source include/have_innodb.inc
+--source include/have_binlog_format_statement.inc
+
+CREATE SEQUENCE seq ENGINE=InnoDB;
+SET SESSION TRANSACTION ISOLATION LEVEL READ COMMITTED;
+--error ER_BINLOG_STMT_MODE_AND_ROW_ENGINE
+INSERT INTO seq VALUES (1,1,100,1,1,1,1,1);
+
+# Cleanup
+DROP SEQUENCE seq;
diff --git a/sql/ha_sequence.cc b/sql/ha_sequence.cc
index df9d9656c56..8bb5a98e39b 100644
--- a/sql/ha_sequence.cc
+++ b/sql/ha_sequence.cc
@@ -322,7 +322,8 @@ int ha_sequence::external_lock(THD *thd, int lock_type)
     Copy lock flag to satisfy DBUG_ASSERT checks in ha_* functions in
     handler.cc when we later call it with file->ha_..()
   */
-  file->m_lock_type= lock_type;
+  if (!error)
+    file->m_lock_type= lock_type;
   return error;
 }