MDEV-29975 InnoDB fails to release savepoint during bulk insert

- InnoDB does rollback the whole transaction and discards the
savepoint when there is a failure happens during bulk
insert operation. When server request to release the savepoint,
InnoDB should return DB_SUCCESS when it deals with bulk
insert operation

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

@@ -214,4 +214,19 @@ WHERE TABLE_NAME='t1' AND TABLE_SCHEMA='test';
 TABLE_ROWS	AVG_ROW_LENGTH>0
 3	1
 DROP TABLE t1;
+#
+# MDEV-29975 InnoDB fails to release savepoint during bulk insert
+#
+CREATE TABLE t (c INT KEY) ENGINE=InnoDB;
+begin;
+INSERT INTO t VALUES (0,0);
+ERROR 21S01: Column count doesn't match value count at row 1
+SAVEPOINT a;
+INSERT INTO t VALUES (0),(0);
+ERROR 23000: Duplicate entry '0' for key 'PRIMARY'
+SAVEPOINT a;
+commit;
+SELECT * FROM t;
+c
+DROP TABLE t;
 # End of 10.6 tests

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

@@ -233,4 +233,18 @@ SELECT TABLE_ROWS, AVG_ROW_LENGTH>0 FROM INFORMATION_SCHEMA.TABLES
 WHERE TABLE_NAME='t1' AND TABLE_SCHEMA='test';
 DROP TABLE t1;
 
+--echo #
+--echo # MDEV-29975 InnoDB fails to release savepoint during bulk insert
+--echo #
+CREATE TABLE t (c INT KEY) ENGINE=InnoDB;
+begin;
+--error ER_WRONG_VALUE_COUNT_ON_ROW
+INSERT INTO t VALUES (0,0);
+SAVEPOINT a;
+--error ER_DUP_ENTRY
+INSERT INTO t VALUES (0),(0);
+SAVEPOINT a;
+commit;
+SELECT * FROM t;
+DROP TABLE t;
 --echo # End of 10.6 tests

storage/innobase/trx/trx0roll.cc

@@ -558,9 +558,13 @@ trx_release_savepoint_for_mysql(
 
 	if (savep != NULL) {
 		trx_roll_savepoint_free(trx, savep);
+		return DB_SUCCESS;
+	} else if (trx->last_sql_stat_start.least_undo_no == 0) {
+		/* Bulk insert could have discarded savepoints */
+		return DB_SUCCESS;
 	}
 
-	return(savep != NULL ? DB_SUCCESS : DB_NO_SAVEPOINT);
+	return DB_NO_SAVEPOINT;
 }
 
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