Assertion `! is_set() || m_can_overwrite_status' in Diagnostics_area::set_error_status (interrupted ALTER TABLE under LOCK)

commit be647ff14d6196af825f05020acee8f18af4773d

Author: Monty

Date:   Fri May 22 18:02:24 2020 +0300

    Fixed deadlock with LOCK TABLES and ALTER TABLE

    MDEV-21398 Deadlock (server hang) or assertion failure in

    Diagnostics_area::set_error_status upon ALTER under lock

CREATE TABLE t1 (a INT);

SELECT * FROM t1;

--connect (con1,localhost,root,,)

--error ER_NO_SUCH_TABLE

ALTER TABLE x MODIFY xx INT;

LOCK TABLE t1 WRITE;

--let $conid = `select connection_id()`

--send

  ALTER TABLE t1 CHANGE COLUMN IF EXISTS b c INT;

--connection default

eval KILL QUERY $conid;

# Cleanup

--disconnect con1

DROP TABLE t1;

CREATE TABLE t1 (a INT);

SELECT * FROM t1;

--error ER_NO_SUCH_TABLE

ALTER TABLE x MODIFY xx INT;

SET SESSION max_session_mem_used= 8192;

LOCK TABLE t1 WRITE;

ALTER TABLE t1 CHANGE COLUMN IF EXISTS b c INT;

DROP TABLE t1;

mariadbd: /data/src/10.5/sql/sql_error.cc:445: void Diagnostics_area::set_error_status(uint, const char*, const char*, const Sql_user_condition_identity&, const Sql_condition*): Assertion `! is_set() || m_can_overwrite_status' failed.

200929  0:18:57 [ERROR] mysqld got signal 6 ;

#7  0x00007ff49fe71f36 in __GI___assert_fail (assertion=0x55eee5195fe8 "! is_set() || m_can_overwrite_status", file=0x55eee5195d80 "/data/src/10.5/sql/sql_error.cc", line=445, function=0x55eee5196010 "void Diagnostics_area::set_error_status(uint, const char*, const char*, const Sql_user_condition_identity&, const Sql_condition*)") at assert.c:101

#8  0x000055eee42b6fee in Diagnostics_area::set_error_status (this=0x7ff47c006a40, sql_errno=1317, message=0x55eee534dc10 "Query execution was interrupted", sqlstate=0x55eee51bfb6b "70100", ucid=..., error_condition=0x0) at /data/src/10.5/sql/sql_error.cc:445

#9  0x000055eee42902e5 in THD::raise_condition (this=0x7ff47c000db8, sql_errno=1317, sqlstate=0x55eee51bfb6b "70100", level=Sql_state_errno_level::WARN_LEVEL_ERROR, ucid=..., msg=0x55eee534dc10 "Query execution was interrupted") at /data/src/10.5/sql/sql_class.cc:1142

#10 0x000055eee41cd31c in THD::raise_condition (this=0x7ff47c000db8, sql_errno=1317, sqlstate=0x0, level=Sql_state_errno_level::WARN_LEVEL_ERROR, msg=0x55eee534dc10 "Query execution was interrupted") at /data/src/10.5/sql/sql_class.h:4533

#11 0x000055eee41c00e3 in my_message_sql (error=1317, str=0x55eee534dc10 "Query execution was interrupted", MyFlags=0) at /data/src/10.5/sql/mysqld.cc:3113

#12 0x000055eee4fc036e in my_message (error=1317, str=0x55eee534dc10 "Query execution was interrupted", MyFlags=0) at /data/src/10.5/mysys/my_error.c:196

#13 0x000055eee421e033 in THD::send_kill_message (this=0x7ff47c000db8) at /data/src/10.5/sql/sql_class.h:4203

#14 0x000055eee4263112 in open_table (thd=0x7ff47c000db8, table_list=0x7ff47c01a990, ot_ctx=0x7ff499f07cd0) at /data/src/10.5/sql/sql_base.cc:1685

#15 0x000055eee426574d in Locked_tables_list::reopen_tables (this=0x7ff47c004d88, thd=0x7ff47c000db8, need_reopen=true) at /data/src/10.5/sql/sql_base.cc:2635

#16 0x000055eee4318fbf in mysql_execute_command (thd=0x7ff47c000db8) at /data/src/10.5/sql/sql_parse.cc:5986

#17 0x000055eee431eeba in mysql_parse (thd=0x7ff47c000db8, rawbuf=0x7ff47c012ac0 "ALTER TABLE t1 CHANGE COLUMN IF EXISTS b c INT", length=46, parser_state=0x7ff499f08510, is_com_multi=false, is_next_command=false) at /data/src/10.5/sql/sql_parse.cc:7994

#18 0x000055eee430b1f8 in dispatch_command (command=COM_QUERY, thd=0x7ff47c000db8, packet=0x7ff47c009099 "ALTER TABLE t1 CHANGE COLUMN IF EXISTS b c INT", packet_length=46, is_com_multi=false, is_next_command=false) at /data/src/10.5/sql/sql_parse.cc:1867

#19 0x000055eee43099ec in do_command (thd=0x7ff47c000db8) at /data/src/10.5/sql/sql_parse.cc:1348

#20 0x000055eee44b577c in do_handle_one_connection (connect=0x55eee6cb1668, put_in_cache=true) at /data/src/10.5/sql/sql_connect.cc:1410

#21 0x000055eee44b54e4 in handle_one_connection (arg=0x55eee6cb1668) at /data/src/10.5/sql/sql_connect.cc:1312

#22 0x000055eee4a119af in pfs_spawn_thread (arg=0x55eee6cb1748) at /data/src/10.5/storage/perfschema/pfs.cc:2201

#23 0x00007ff4a0389609 in start_thread (arg=<optimized out>) at pthread_create.c:477

#24 0x00007ff49ff5d293 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Trying to get some variables.

Some pointers may be invalid and cause the dump to abort.

Query (0x7f916c013f20): ALTER TABLE t1 CHANGE COLUMN IF EXISTS b c INT

Connection ID (thread ID): 4

Status: KILL_QUERY