#
# MDEV-12882 - Assertion `mdl_ticket->m_type == MDL_SHARED_UPGRADABLE ||
#                         mdl_ticket->m_type == MDL_SHARED_NO_WRITE ||
#                         mdl_ticket->m_type == MDL_SHARED_NO_READ_WRITE ||
#                         mdl_ticket->m_type == MDL_SHARED_READ'
#                         failed in MDL_context::upgrade_shared_lock
#
CREATE TABLE t1(a INT) ENGINE=InnoDB;
LOCK TABLES t1 WRITE CONCURRENT, t1 AS t2 READ;
SELECT LOCK_MODE, LOCK_TYPE, TABLE_SCHEMA, TABLE_NAME FROM information_schema.metadata_lock_info;
LOCK_MODE	LOCK_TYPE	TABLE_SCHEMA	TABLE_NAME
MDL_INTENTION_EXCLUSIVE	Global read lock		
MDL_SHARED_NO_READ_WRITE	Table metadata lock	test	t1
UNLOCK TABLES;
LOCK TABLES t1 AS t2 READ, t1 WRITE CONCURRENT;
SELECT LOCK_MODE, LOCK_TYPE, TABLE_SCHEMA, TABLE_NAME FROM information_schema.metadata_lock_info;
LOCK_MODE	LOCK_TYPE	TABLE_SCHEMA	TABLE_NAME
MDL_INTENTION_EXCLUSIVE	Global read lock		
MDL_SHARED_WRITE	Table metadata lock	test	t1
MDL_SHARED_READ_ONLY	Table metadata lock	test	t1
UNLOCK TABLES;
DROP TABLE t1;