MDEV-21675: Data inconsistency after multirow insert rollback (#1474)

* Remove dead code

* MDEV-21675 Data inconsistency after multirow insert rollback

This patch fixes data inconsistencies that happen after rollback of
multirow inserts, with binlog disabled.
For example, statements such as `INSERT INTO t1 VALUES (1,'a'),(1,'b')`
that fail with duplicate key error. In such cases the whole statement
is rolled back. However, with wsrep_emulate_binlog in effect, the
IO_CACHE would not be truncated, and the pending rows events would be
replicated to the rest of the cluster. In the above example, it would
result in row (1,'a') being replicated, whereas locally the statement
is rolled back entirely. Making the cluster inconsistent.
The patch changes the code so that prior to statement rollback,
pending rows event are removed and the stmt cache reset.
That patch also introduces MTR tests that excercise multirow insert
statements for regular, and streaming replication.

1 files changed, 89 insertions, 0 deletions

diff --git a/mysql-test/suite/galera/t/galera_multirow_rollback.test b/mysql-test/suite/galera/t/galera_multirow_rollback.test
new file mode 100644
index 00000000000..a5aaedd8bd4
--- /dev/null
+++ b/mysql-test/suite/galera/t/galera_multirow_rollback.test
@@ -0,0 +1,89 @@
+#
+# Test multirow insert rollback
+#
+
+--source include/galera_cluster.inc
+
+#
+# Case 1: error on multirow insert results in empty transaction
+#
+CREATE TABLE t1 (f1 INTEGER PRIMARY KEY DEFAULT 0, f2 char(12));
+
+--connection node_1
+START TRANSACTION;
+--error ER_DUP_ENTRY
+INSERT INTO t1 (f2) VALUES ('a'), ('b');
+COMMIT;
+
+SELECT COUNT(*) AS expect_0 FROM t1;
+
+--connection node_2
+SELECT COUNT(*) AS expect_0 FROM t1;
+
+DROP TABLE t1;
+
+
+#
+# Case 2: error on multirow insert does not affect previous statements
+#
+CREATE TABLE t1 (f1 INTEGER PRIMARY KEY DEFAULT 0, f2 char(12));
+
+--connection node_1
+START TRANSACTION;
+INSERT INTO t1 VALUES (1, 'a');
+INSERT INTO t1 VALUES (2, 'b');
+--error ER_DUP_ENTRY
+INSERT INTO t1 (f2) VALUES ('c'), ('d');
+COMMIT;
+
+--echo expect (1,'a'), (2, 'b')
+SELECT * FROM t1;
+
+--connection node_2
+--echo expect (1,'a'), (2, 'b')
+SELECT * FROM t1;
+
+DROP TABLE t1;
+
+
+#
+# Case 3: error on autocommit multirow insert
+#
+CREATE TABLE t1 (f1 INTEGER PRIMARY KEY DEFAULT 0, f2 char(12));
+
+--connection node_1
+--error ER_DUP_ENTRY
+INSERT INTO t1 (f2) VALUES ('a'),('b');
+
+SELECT COUNT(*) AS expect_0 FROM t1;
+
+--connection node_2
+SELECT COUNT(*) AS expect_0 FROM t1;
+
+DROP TABLE t1;
+
+
+#
+# Case 4: FK constraint violation on multirow insert
+#
+--connection node_1
+CREATE TABLE p(id int primary key, j int) ENGINE=InnoDB;
+CREATE TABLE c(id int primary key, fk1 int) ENGINE=InnoDB;
+ALTER TABLE c ADD FOREIGN KEY (fk1) references p(id);
+INSERT INTO p VALUES(1, 0);
+
+START TRANSACTION;
+INSERT INTO c VALUES (3,1);
+--error ER_NO_REFERENCED_ROW_2
+INSERT INTO c VALUES (1,1), (2,2);
+COMMIT;
+
+SELECT * FROM p;
+SELECT * FROM c;
+
+--connection node_2
+SELECT * FROM p;
+SELECT * FROM c;
+
+DROP TABLE c;
+DROP TABLE p;