When we cast datetime value to DATE (TIME) type we should throw away its
time (date) part. This was not done properly if CAST() function was used
in datetime expressions.
Fix InnoDB critical bug #7496; we scan the InnoDB data dictionary also at a normal mysqld startup, and create the spaces, so that we know the mapping space id -> .ibd file name; fix an infinite loop if DISCARD TABLESPACE coincides with INSERT or some other table operation; fix a potential crash if DISCARD TABLESPACE coincides with a cascaded FOREIGN KEY operation in the same table; do not allow DISCARD TABLESPACE of a referenced table if FOREIGN_KEY_CHECKS=1
Added test cases for bug #7351.
item_cmpfunc.cc:
Fixed bug #7351: incorrect result for a query with a
subquery returning empty set.
If in the predicate v IN (SELECT a FROM t WHERE cond)
v is null, then the result of the predicate is either
INKNOWN or FALSE. It is FALSE if the subquery returns
an empty set.
item_subselect.cc:
Fixed bug #7351: incorrect result for a query with a
subquery returning empty set.
The problem was due to not a quite legal transformation
for 'IN' subqueries. A subquery containing a predicate
of the form
v IN (SELECT a FROM t WHERE cond)
was transformed into
EXISTS(SELECT a FROM t WHERE cond AND (a=v OR a IS NULL)).
Yet, this transformation is valid only if v is not null.
If v is null, then, in the case when
(SELECT a FROM t WHERE cond) returns an empty set the value
of the predicate is FALSE, otherwise the result of the
predicate is INKNOWN.
The fix resolves this problem by changing the result
of the transformation to
EXISTS(SELECT a FROM t WHERE cond AND (v IS NULL OR (a=v OR a IS NULL)))
in the case when v is nullable.
The new transformation prevents applying the lookup
optimization for IN subqueries. To make it still
applicable we have to introduce guarded access methods.
to behave well on 5.0 tables (well now you can't use tables from 4.1
and 5.0 with 4.0 because former use utf8, but still it is nice to have
similar code in acl_init() and replace_user_table()).
This also will make such GRANTs working in 5.0 (they are broken now).
STR_TO_DATE() function if there is another format specifier after %f
in format string". Also small cleanup of STR_TO_DATE() implementation.
(After review version.)
Add a comment that no InnoDB table lock is now acquired in LOCK TABLES if AUTOCOMMIT=1. This helps to avoid deadlocks when porting old MyISAM applications to InnoDB.
