MDEV-22434 UPDATE on RocksDB table with WITHOUT OVERLAPS fails

Insert worked incorrect as well. RocksDB used table->record[0] internally to store some
intermediate results for key conversion, during index searching among other operations.
So table->record[0] is spoiled during ha_rnd_index_map in ha_check_overlaps, so in turn
the broken record data was inserted.

The fix is to store RocksDB intermediate result in its own buffer instead of table->record[0].

`rocksdb` MTR suite is is checked and runs fine.
No need for additional tests. The existing overlaps.test covers the case completely.
However, I am not going to add anything related to rocksdb to suite, to keep it away
from additional dependencies.

To run tests with RocksDB engine, one can add following to engines.combinations:
[rocksdb]
plugin-load=$HA_ROCKSDB_SO
default-storage-engine=rocksdb
rocksdb

2 files changed, 2 insertions, 2 deletions

diff --git a/mysql-test/suite/period/r/overlaps.result b/mysql-test/suite/period/r/overlaps.result
index 4e388d7033e..74faf6819d0 100644
--- a/mysql-test/suite/period/r/overlaps.result
+++ b/mysql-test/suite/period/r/overlaps.result
@@ -175,7 +175,7 @@ insert into t values (3, NULL, '2003-03-01', '2003-05-01');
 insert into t values (1, 1, '2003-03-01', '2003-05-01');
 insert into t values (1, 2, '2003-05-01', '2003-07-01');
 insert into t values (4, NULL, '2003-03-01', '2003-05-01');
-create sequence seq start=5;
+create sequence seq start=5 engine=myisam;
 update t set id= nextval(seq), u= nextval(seq), s='2003-05-01', e='2003-07-01'
          where u is NULL;
 select * from t;
diff --git a/mysql-test/suite/period/t/overlaps.test b/mysql-test/suite/period/t/overlaps.test
index 54dd60e0072..706ea805908 100644
--- a/mysql-test/suite/period/t/overlaps.test
+++ b/mysql-test/suite/period/t/overlaps.test
@@ -157,7 +157,7 @@ insert into t values (1, 1, '2003-03-01', '2003-05-01');
 insert into t values (1, 2, '2003-05-01', '2003-07-01');
 insert into t values (4, NULL, '2003-03-01', '2003-05-01');
 
-create sequence seq start=5;
+create sequence seq start=5 engine=myisam;
 update t set id= nextval(seq), u= nextval(seq), s='2003-05-01', e='2003-07-01'
          where u is NULL;