- In function 'handle_grant_struct' when searching the memory structures for an
entry to modify, convert all entries here host.hostname is NULL to "" and compare that
with the host passed in argument "user_from".
- A user created with hostname "" is stored in "mysql.user" table as host="" but when loaded into
memory it'll be stored as host.hostname NULL. Specifiying "" as hostname means
that "any host" can connect. Thus is's correct to turn on allow_all_hosts
when such a user is found.
- Review and fix other places where host.hostname may be NULL.
When a CREATE TABLE command created a table from a materialized
view id does not inherit default values from the underlying table.
Moreover the temporary table used for the view materialization
does not inherit those default values.
In the case when the underlying table contained ENUM fields it caused
misleading error messages. In other cases the created table contained
wrong default values.
The code was modified to ensure inheritance of default values for
materialized views.
This bug was introduced when the patch resolving the
performance problem 17164 was applied. As a result
of that modification the not_null_tables attributes
were calculated incorrectly for constant OR conditions.
This triggered invalid conversion of outer joins into
inner joins.
The convert_constant_item() function converts constant items to ints on
prepare phase to optimize execution speed. In this case it tries to evaluate
subselect which contains a derived table and is contained in a derived table.
All derived tables are filled only after all derived tables are prepared.
So evaluation of subselect with derived table at the prepare phase will
return a wrong result.
A new flag with_subselect is added to the Item class. It indicates that
expression which this item represents is a subselect or contains a subselect.
It is set to 0 by default. It is set to 1 in the Item_subselect constructor
for subselects.
For Item_func and Item_cond derived classes it is set after fixing any argument
in Item_func::fix_fields() and Item_cond::fix_fields accordingly.
The convert_constant_item() function now doesn't convert a constant item
if the with_subselect flag set in it.
The select statement that specified a view could be
slightly changed when the view was saved in a frm file.
In particular references to an alias name in the HAVING
clause could be substituted for the expression named by
this alias.
This could result in an error message for a query of
the form SELECT * FROM <view>. Yet no such message
appeared when executing the query specifying the view.
