MDEV-28820 MyISAM wrong server status flags

MyISAM tables no longer take transactional metadata locks
unless there already is an active transaction.

mysql-test/main/mdl.result

@@ -88,3 +88,47 @@ unlock tables;
 connection default;
 disconnect locker;
 DROP TABLE t1,t3;
+#
+# MDEV-28820 MyISAM wrong server status flags
+#
+create table t1 (a int);
+set autocommit=0;
+select @@in_transaction;
+@@in_transaction
+0
+select * from t1;
+a
+select @@in_transaction;
+@@in_transaction
+0
+connect foo,localhost,root;
+drop table t1;
+connection default;
+set autocommit=1;
+create table t1 (a int);
+create table t2 (b int) engine=innodb;
+set autocommit=0;
+select @@in_transaction;
+@@in_transaction
+0
+select * from t2;
+b
+select @@in_transaction;
+@@in_transaction
+1
+select * from t1;
+a
+connection foo;
+drop table t1;
+connection default;
+select * from t1;
+a
+commit;
+connection foo;
+disconnect foo;
+connection default;
+set autocommit=default;
+drop table t2;
+#
+# End of 10.4 tests
+#

mysql-test/main/mdl.test

@@ -80,3 +80,46 @@ connection default;
 disconnect locker;
 DROP TABLE t1,t3;
 --enable_service_connection
+
+--echo #
+--echo # MDEV-28820 MyISAM wrong server status flags
+--echo #
+# MyISAM alone doesn't start a transaction or takes transactional MDL
+create table t1 (a int);
+set autocommit=0;
+select @@in_transaction;
+select * from t1;
+select @@in_transaction;
+connect foo,localhost,root;
+drop table t1;
+connection default;
+set autocommit=1;
+
+# MyISAM in a transaction (started by InnoDB) takes transactional MDL all right
+create table t1 (a int);
+create table t2 (b int) engine=innodb;
+set autocommit=0;
+select @@in_transaction;
+select * from t2;
+select @@in_transaction;
+select * from t1;
+connection foo;
+send drop table t1;
+connection default;
+let $wait_condition=
+  select count(*) > 0 from information_schema.processlist
+  where state = "Waiting for table metadata lock";
+--source include/wait_condition.inc
+select * from t1;
+commit;
+
+connection foo;
+reap;
+disconnect foo;
+connection default;
+set autocommit=default;
+drop table t2;
+
+--echo #
+--echo # End of 10.4 tests
+--echo #

mysql-test/main/myisam_recover.result

@@ -126,7 +126,7 @@ test.t1	check	error	Record-count is not ok; is 2   Should be: 1
 test.t1	check	warning	Found 2 key parts. Should be: 1
 test.t1	check	error	Corrupt
 # At this point we have a corrupt t1
-set autocommit = 0;
+start transaction;
 select * from t2;
 a
 1
@@ -145,7 +145,6 @@ ALTER TABLE t2 ADD val INT;
 connection default;
 # With fix we should have alter table waiting for t2 lock here.
 ROLLBACK;
-SET autocommit = 1;
 connection con2;
 connection default;
 disconnect con2;

mysql-test/main/myisam_recover.test

@@ -135,7 +135,7 @@ flush table t1;
 check table t1;
 
 --echo # At this point we have a corrupt t1
-set autocommit = 0;
+start transaction;
 select * from t2;
 --echo # Without fix select from t1 will break the transaction. After the fix
 --echo # transaction should be active and should hold lock on table t2. Alter
@@ -153,7 +153,6 @@ let $wait_condition=
   LIKE "Waiting%" AND info = "ALTER TABLE t2 ADD val INT";
 --source include/wait_condition.inc
 ROLLBACK;
-SET autocommit = 1;
 
 connection con2;
 --reap

mysql-test/main/schema.result

@@ -18,14 +18,14 @@ connect con2, localhost, root;
 connection default;
 CREATE SCHEMA schema1;
 CREATE TABLE schema1.t1 (a INT);
-SET autocommit= FALSE;
+START TRANSACTION;
 INSERT INTO schema1.t1 VALUES (1);
 connection con2;
 DROP SCHEMA schema1;
 connection default;
 ALTER SCHEMA schema1 DEFAULT CHARACTER SET utf8;
 Got one of the listed errors
-SET autocommit= TRUE;
+COMMIT;
 connection con2;
 connection default;
 disconnect con2;

mysql-test/main/schema.test

@@ -25,7 +25,7 @@ connection default;
 CREATE SCHEMA schema1;
 CREATE TABLE schema1.t1 (a INT);
 
-SET autocommit= FALSE;
+START TRANSACTION;
 INSERT INTO schema1.t1 VALUES (1);
 
 connection con2;
@@ -40,7 +40,7 @@ let $wait_condition= SELECT COUNT(*)= 1 FROM information_schema.processlist
 # Listing the error twice to prevent result diffences based on filename.
 --error 1,1
 ALTER SCHEMA schema1 DEFAULT CHARACTER SET utf8;
-SET autocommit= TRUE;
+COMMIT;
 
 connection con2;
 --reap

mysql-test/main/sp-lock.result

@@ -463,8 +463,8 @@ drop function f1;
 create function f1() returns varchar(20) return "f1()";
 create function f2() returns varchar(20) return "f2()";
 create view v1 as select f1() as a;
-set @@session.autocommit=0;
 lock table v1 read;
+start transaction;
 select * from v1;
 a
 f1()
@@ -486,6 +486,7 @@ connection con2;
 # Reaping 'drop function f2'...
 connection default;
 unlock tables;
+commit;
 connection con1;
 # Reaping 'drop function f1'...
 connection default;
@@ -494,7 +495,6 @@ ERROR 42000: FUNCTION test.f1 does not exist
 drop function f2;
 ERROR 42000: FUNCTION test.f2 does not exist
 drop view v1;
-set @@session.autocommit=default;
 # 
 # 8) Check the situation when we're preparing or executing a
 # prepared statement, and as part of that try to flush the

mysql-test/main/sp-lock.test

@@ -537,8 +537,8 @@ drop function f1;
 create function f1() returns varchar(20) return "f1()";
 create function f2() returns varchar(20) return "f2()";
 create view v1 as select f1() as a;
-set @@session.autocommit=0;
 lock table v1 read;
+start transaction;
 select * from v1;
 savepoint sv;
 select f2();
@@ -565,6 +565,7 @@ connection con2;
 reap;
 connection default;
 unlock tables;
+commit;
 connection con1;
 --echo # Reaping 'drop function f1'...
 reap;
@@ -574,7 +575,6 @@ drop function f1;
 --error ER_SP_DOES_NOT_EXIST
 drop function f2;
 drop view v1;
-set @@session.autocommit=default;
 
 --echo # 
 --echo # 8) Check the situation when we're preparing or executing a

sql/sql_parse.cc

@@ -6319,7 +6319,7 @@ finish:
       thd->release_transactional_locks();
     }
   }
-  else if (! thd->in_sub_stmt && ! thd->in_multi_stmt_transaction_mode())
+  else if (! thd->in_sub_stmt && ! thd->in_active_multi_stmt_transaction())
   {
     /*
       - If inside a multi-statement transaction,