Item_func_user doesn't calculate anything in it's val_str() method,
just returns saved str_value.
Though Item::save_in_field method can destroy str_value, relying on
val_str() return. As a result we get the garbage stored in field.
We cannot use Item::save_in_field implementation for Item_func_user,
reimplement it in simpler way.
After dumping triggers mysqldump copied
the value of the OLD_SQL_MODE variable to the SQL_MODE
variable. If the --compact option of the mysqldump was
not set the OLD_SQL_MODE variable had the value
of the uninitialized SQL_MODE variable. So
usually the NO_AUTO_VALUE_ON_ZERO option of the
SQL_MODE variable was discarded.
This fix is for non-"--compact" mode of the mysqldump,
because mysqldump --compact never set SQL_MODE to the
value of NO_AUTO_VALUE_ON_ZERO.
The dump_triggers_for_table function has been modified
to restore previous value of the SQL_MODE variable after
dumping triggers using the SAVE_SQL_MODE temporary
variable.
unpack_fields() didn't expect NULL_LENGHT in the field's descriptions.
In this case we get NULL in the resulting string so cannot use
strdup_root to make a copy of it.
strdup_root changed with strmake_root as it's NULL-safe
The Item_date_typecast::val_int function doesn't reset null_value flag.
This makes all values that follows the first null value to be treated as nulls
and led to a wrong result.
Now the Item_date_typecast::val_int function correctly sets the null_value flag
for both null and non-null values.
a temporary table.
The result string of the Item_func_group_concat wasn't initialized in the
copying constructor of the Item_func_group_concat class. This led to a
wrong charset of GROUP_CONCAT result when the select employs a temporary
table.
The copying constructor of the Item_func_group_concat class now correctly
initializes the charset of the result string.
Optimization of queries with DETERMINISTIC functions in the
WHERE clause was not effective: sequential scan was always
used.
Now a SF with the DETERMINISTIC flags is treated as constant
when it's arguments are constants (or a SF doesn't has arguments).
For each view the mysqldump utility creates a temporary table
with the same name and the same columns as the view
in order to satisfy views that depend on this view.
After the creation of all tables, mysqldump drops all
temporary tables and creates actual views.
However, --skip-add-drop-table and --compact flags disable
DROP TABLE statements for those temporary tables. Thus, it was
impossible to create the views because of existence of the
temporary tables with the same names.
