Field::make_new_field() resets invisible property (needed for "CREATE
.. SELECT" f.ex.). Recover invisible property in
Delayed_insert::get_local_table() (unireg_check works by the same
principle).
For a unique key if all the keyparts are NOT NULL or the predicates involving
the keyparts is NULL rejecting, then we can use EQ_REF access instead of ref
access with the unique key
insert into table with TIMESTAMP INVISIBLE
Problem:- The segfault occurs because value is null but since timestamp field
is VISIBLE it expects a value , and it tries to call value->save_in_field(..
Timestamp field should not be visible this is the problem.
Solution:- While we clone field for record0_field we don't honor the field
_visibility , this patch changes that.
