MDEV-28400 Leak in trx_mod_time_t::start_bulk_insert()

- Change partition does undo logging of all rows unnecessarily and
it invokes bulk insert during DDL. Better to avoid the logging of undo
records during copy of the parititon.

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

@@ -296,3 +296,11 @@ t1	CREATE TABLE `t1` (
 ) ENGINE=InnoDB DEFAULT CHARSET=latin1
 CREATE TABLE t2(d INT)ENGINE=InnoDB;
 DROP TABLE t2, t1;
+#
+#  MDEV-28400 Leak in trx_mod_time_t::start_bulk_insert
+#
+SET SESSION foreign_key_checks=0;
+CREATE TABLE t1 (a INT) ENGINE=InnoDB PARTITION BY HASH(a) PARTITIONS 2;
+INSERT INTO t1 VALUES (1),(2);
+ALTER TABLE t1 REBUILD PARTITION p0;
+DROP TABLE t1;

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

@@ -304,3 +304,14 @@ SET SESSION foreign_key_checks=TRUE;
 SHOW CREATE TABLE t1;
 CREATE TABLE t2(d INT)ENGINE=InnoDB;
 DROP TABLE t2, t1;
+
+--echo #
+--echo #  MDEV-28400 Leak in trx_mod_time_t::start_bulk_insert
+--echo #
+
+SET SESSION foreign_key_checks=0;
+CREATE TABLE t1 (a INT) ENGINE=InnoDB PARTITION BY HASH(a) PARTITIONS 2;
+INSERT INTO t1 VALUES (1),(2);
+ALTER TABLE t1 REBUILD PARTITION p0;
+# Cleanup
+DROP TABLE t1;

sql/ha_partition.cc

@@ -2143,7 +2143,10 @@ int ha_partition::change_partitions(HA_CREATE_INFO *create_info,
   }
   DBUG_ASSERT(m_new_file == 0);
   m_new_file= new_file_array;
-  if (unlikely((error= copy_partitions(copied, deleted))))
+  (*m_new_file)->extra(HA_EXTRA_BEGIN_ALTER_COPY);
+  error= copy_partitions(copied, deleted);
+  (*m_new_file)->extra(HA_EXTRA_END_ALTER_COPY);
+  if (unlikely(error))
   {
     /*
       Close and unlock the new temporary partitions.