MDEV-36330: SERIALIZABLE read inconsistency

mysql-test/suite/innodb/r/lock_isolation.result

@@ -166,7 +166,6 @@ SELECT * FROM t FORCE INDEX (b) FOR UPDATE;
 a	b
 1	NULL
 COMMIT;
-disconnect con_weird;
 connection consistent;
 SELECT * FROM t FORCE INDEX (b) FOR UPDATE;
 a	b
@@ -230,9 +229,35 @@ UPDATE t SET b=4 WHERE a=1;
 connection consistent;
 SELECT * FROM t WHERE a=1 FOR UPDATE;
 ERROR HY000: Record has changed since last read in table 't'
-disconnect consistent;
 disconnect disable_purging;
 connection default;
 SET DEBUG_SYNC="RESET";
 DROP TABLE t;
+CREATE TABLE t1(a INT) ENGINE=InnoDB STATS_PERSISTENT=0;
+CREATE TABLE t2(a INT) ENGINE=InnoDB STATS_PERSISTENT=0;
+BEGIN;
+INSERT INTO t1 SET a=1;
+connection con_weird;
+SET TRANSACTION ISOLATION LEVEL SERIALIZABLE;
+BEGIN;
+INSERT INTO t2 SET a=1;
+connection consistent;
+SET TRANSACTION ISOLATION LEVEL SERIALIZABLE;
+BEGIN;
+INSERT INTO t2 SET a=2;
+connection default;
+COMMIT;
+connection con_weird;
+SELECT * FROM t1;
+a
+1
+COMMIT;
+disconnect con_weird;
+connection consistent;
+SELECT * FROM t1;
+ERROR HY000: Record has changed since last read in table 't1'
+COMMIT;
+disconnect consistent;
+connection default;
+DROP TABLE t1,t2;
 # End of 10.6 tests

mysql-test/suite/innodb/t/lock_isolation.test

@@ -174,7 +174,6 @@ ROLLBACK;
 --reap
 SELECT * FROM t FORCE INDEX (b) FOR UPDATE;
 COMMIT;
---disconnect con_weird
 
 --connection consistent
 SELECT * FROM t FORCE INDEX (b) FOR UPDATE;
@@ -246,12 +245,34 @@ UPDATE t SET b=4 WHERE a=1;
 --connection consistent
 --error ER_CHECKREAD
 SELECT * FROM t WHERE a=1 FOR UPDATE;
---disconnect consistent
 --disconnect disable_purging
 
 --connection default
 SET DEBUG_SYNC="RESET";
 DROP TABLE t;
 
+CREATE TABLE t1(a INT) ENGINE=InnoDB STATS_PERSISTENT=0;
+CREATE TABLE t2(a INT) ENGINE=InnoDB STATS_PERSISTENT=0;
+BEGIN; INSERT INTO t1 SET a=1;
+--connection con_weird
+SET TRANSACTION ISOLATION LEVEL SERIALIZABLE;
+BEGIN; INSERT INTO t2 SET a=1;
+--connection consistent
+SET TRANSACTION ISOLATION LEVEL SERIALIZABLE;
+BEGIN; INSERT INTO t2 SET a=2;
+--connection default
+COMMIT;
+--connection con_weird
+SELECT * FROM t1;
+COMMIT;
+--disconnect con_weird
+--connection consistent
+--error ER_CHECKREAD
+SELECT * FROM t1;
+COMMIT;
+--disconnect consistent
+--connection default
+DROP TABLE t1,t2;
+
 --source include/wait_until_count_sessions.inc
 --echo # End of 10.6 tests

sql/transaction.cc

@@ -217,7 +217,8 @@ bool trans_begin(THD *thd, uint flags)
 #endif //EMBEDDED_LIBRARY
 
   /* ha_start_consistent_snapshot() relies on OPTION_BEGIN flag set. */
-  if (flags & MYSQL_START_TRANS_OPT_WITH_CONS_SNAPSHOT)
+  if ((flags & MYSQL_START_TRANS_OPT_WITH_CONS_SNAPSHOT) ||
+      thd->tx_isolation == ISO_SERIALIZABLE)
   {
 #ifndef EMBEDDED_LIBRARY
     if (thd->variables.session_track_transaction_info > TX_TRACK_NONE)

storage/innobase/handler/ha_innodb.cc

@@ -4476,15 +4476,14 @@ innobase_start_trx_and_assign_read_view(
 	trx->isolation_level = innobase_map_isolation_level(
 		thd_get_trx_isolation(thd)) & 3;
 
-	if (trx->isolation_level == TRX_ISO_REPEATABLE_READ) {
+	if (trx->isolation_level != TRX_ISO_READ_UNCOMMITTED) {
 		trx->read_view.open(trx);
 	} else {
 		push_warning_printf(thd, Sql_condition::WARN_LEVEL_WARN,
 				    HA_ERR_UNSUPPORTED,
 				    "InnoDB: WITH CONSISTENT SNAPSHOT"
-				    " was ignored because this phrase"
-				    " can only be used with"
-				    " REPEATABLE READ isolation level.");
+				    " is ignored at READ UNCOMMITTED"
+				    " isolation level.");
 	}
 
 	/* Set the MySQL flag to mark that there is an active transaction */

storage/innobase/mysql-test/storage_engine/trx/cons_snapshot_serializable.rdiff

@@ -1,14 +1,6 @@
 --- suite/storage_engine/trx/cons_snapshot_serializable.result
 +++ suite/storage_engine/trx/cons_snapshot_serializable.reject
-@@ -5,12 +5,15 @@
- CREATE TABLE t1 (a <INT_COLUMN>) ENGINE=<STORAGE_ENGINE> <CUSTOM_TABLE_OPTIONS>;
- SET SESSION TRANSACTION ISOLATION LEVEL SERIALIZABLE;
- START TRANSACTION WITH CONSISTENT SNAPSHOT;
-+Warnings:
-+Warning	138	InnoDB: WITH CONSISTENT SNAPSHOT was ignored because this phrase can only be used with REPEATABLE READ isolation level.
- connection con2;
- INSERT INTO t1 (a) VALUES (1);
- connection con1;
+@@ -11,6 +11,7 @@
  # If consistent read works on this isolation level (SERIALIZABLE), the following SELECT should not return the value we inserted (1)
  SELECT a FROM t1;
  a

storage/innobase/mysql-test/storage_engine/trx/level_read_uncommitted.rdiff

@@ -5,7 +5,7 @@
  SET SESSION TRANSACTION ISOLATION LEVEL READ UNCOMMITTED;
  START TRANSACTION WITH CONSISTENT SNAPSHOT;
 +Warnings:
-+Warning	138	InnoDB: WITH CONSISTENT SNAPSHOT was ignored because this phrase can only be used with REPEATABLE READ isolation level.
++Warning	138	InnoDB: WITH CONSISTENT SNAPSHOT is ignored at READ UNCOMMITTED isolation level.
  connection con2;
  INSERT INTO t1 (a) VALUES (1);
  connection con1;