Draft patch that fixes and a sketches test cases for:

Bug#20837 Apparent change of isolation level during transaction,
Bug#46527 COMMIT AND CHAIN RELEASE does not make sense,
Bug#53343 completion_type=1, COMMIT/ROLLBACK AND CHAIN don't 
preserve the isolation level
Bug#53346 completion_type has strange effect in a stored 
procedure/prepared statement

Make thd->tx_isolation mean strictly "current transaction 
isolation level"
Make thd->variables.tx_isolation mean "current session isolation
level".
The current transaction isolation level is now established
at transaction start. If there was a SET TRANSACTION
ISOLATION LEVEL statement, the value is taken from it.
Otherwise, the session value is used.
A change in a session value, made while a transaction is active,
whereas still allowed, no longer has any effect on the
current transaction isolation level. This is an incompatible
change.
A change in a session isolation level, made while there is
no active transaction, overrides SET TRANSACTION statement,
if there was any.
Changed the impelmentation to not look at @@session.completion_type
in the parser, and thus fixed Bug#53346.
Changed the parser to not allow AND NO CHAIN RELEASE,
and thus fixed Bug#46527.
Changed the transaction API to take the current transaction
isolation level into account:
- BEGIN/COMMIT now do preserve the current transaction
isolation level if chaining is on.
- implicit commit, XA COMMIT or XA ROLLBACK or autocommit don't.

1 files changed, 14 insertions, 14 deletions

diff --git a/mysql-test/suite/binlog/t/binlog_innodb.test b/mysql-test/suite/binlog/t/binlog_innodb.test
index c33a31a30f2..13edf262026 100644
--- a/mysql-test/suite/binlog/t/binlog_innodb.test
+++ b/mysql-test/suite/binlog/t/binlog_innodb.test
@@ -8,14 +8,14 @@ RESET MASTER;
 CREATE TABLE t1 (a INT PRIMARY KEY, b INT) ENGINE=INNODB;
 INSERT INTO t1 VALUES (1,1),(2,2),(3,3),(4,4),(5,5),(6,6);
 
-BEGIN;
 SET SESSION TRANSACTION ISOLATION LEVEL REPEATABLE READ;
+BEGIN;
 # Should be logged as statement
 UPDATE t1 SET b = 2*a WHERE a > 1;
 COMMIT;
 
-BEGIN;
 SET SESSION TRANSACTION ISOLATION LEVEL READ COMMITTED;
+BEGIN;
 # Should be logged as rows
 UPDATE t1 SET b = a * a WHERE a > 3;
 COMMIT;
@@ -25,69 +25,69 @@ COMMIT;
 
 SET BINLOG_FORMAT=STATEMENT;
 
-BEGIN;
 SET SESSION TRANSACTION ISOLATION LEVEL READ UNCOMMITTED;
+BEGIN;
 error ER_BINLOG_STMT_MODE_AND_ROW_ENGINE;
 UPDATE t1 SET b = 1*a WHERE a > 1;
 COMMIT;
 
-BEGIN;
 SET SESSION TRANSACTION ISOLATION LEVEL READ COMMITTED;
+BEGIN;
 error ER_BINLOG_STMT_MODE_AND_ROW_ENGINE;
 UPDATE t1 SET b = 2*a WHERE a > 2;
 COMMIT;
 
-BEGIN;
 SET SESSION TRANSACTION ISOLATION LEVEL REPEATABLE READ;
+BEGIN;
 UPDATE t1 SET b = 3*a WHERE a > 3;
 COMMIT;
 
-BEGIN;
 SET SESSION TRANSACTION ISOLATION LEVEL SERIALIZABLE;
+BEGIN;
 UPDATE t1 SET b = 4*a WHERE a > 4;
 COMMIT;
 
 SET BINLOG_FORMAT=MIXED;
 
-BEGIN;
 SET SESSION TRANSACTION ISOLATION LEVEL READ UNCOMMITTED;
+BEGIN;
 UPDATE t1 SET b = 1*a WHERE a > 1;
 COMMIT;
 
-BEGIN;
 SET SESSION TRANSACTION ISOLATION LEVEL READ COMMITTED;
+BEGIN;
 UPDATE t1 SET b = 2*a WHERE a > 2;
 COMMIT;
 
-BEGIN;
 SET SESSION TRANSACTION ISOLATION LEVEL REPEATABLE READ;
+BEGIN;
 UPDATE t1 SET b = 3*a WHERE a > 3;
 COMMIT;
 
-BEGIN;
 SET SESSION TRANSACTION ISOLATION LEVEL SERIALIZABLE;
+BEGIN;
 UPDATE t1 SET b = 4*a WHERE a > 4;
 COMMIT;
 
 SET BINLOG_FORMAT=ROW;
 
-BEGIN;
 SET SESSION TRANSACTION ISOLATION LEVEL READ UNCOMMITTED;
+BEGIN;
 UPDATE t1 SET b = 1*a WHERE a > 1;
 COMMIT;
 
-BEGIN;
 SET SESSION TRANSACTION ISOLATION LEVEL READ COMMITTED;
+BEGIN;
 UPDATE t1 SET b = 2*a WHERE a > 2;
 COMMIT;
 
-BEGIN;
 SET SESSION TRANSACTION ISOLATION LEVEL REPEATABLE READ;
+BEGIN;
 UPDATE t1 SET b = 3*a WHERE a > 3;
 COMMIT;
 
-BEGIN;
 SET SESSION TRANSACTION ISOLATION LEVEL SERIALIZABLE;
+BEGIN;
 UPDATE t1 SET b = 4*a WHERE a > 4;
 COMMIT;