fixing test results accordingly.
func_system.test:
New test that illegal mix of collations does not happen anymore.
item_strfunc.h:
safe_charset_converter() was added for system constants.
item_strfunc.cc:
safe_charset_converter() was added for system constants.
item_func.cc, item.h, item.cc:
Bug#8291: Illegal collation mix with USER() function.
After discussion with PeterG and Serge, a new coercibility
level for "system constants" was introduced, between
COERRIBLE and IMPLICIT. Thus:
SELECT col1 = USER() FROM t1; - is done according to col1 collation.
SELECT 'string' = USER(); - is done according to USER() collation.
At the same time, "nagg" and "strong" members were removed as unused.
item_create.cc:
Version is a system constant too.
independently from the expression it is initialized from.
In other words, this change treats a user variable like
a table with one column and one record. Discussed with
PeterG, Serg and Lars. This change also simplifies replication
allowing not to replicate variables' coercibility.
Ensure that references in HAVING, ORDER BY or GROUP BY are calculated after fields in SELECT.
This will ensure that any reference to these has a valid value.
Generalized the code for split_sum_func()
For numeric constants we only need to add, since the parser doesn't produce
negative numbers.
For strings we only add (we actually could substract 1 if given string is a constant
and it has '-number' form but we're not doing that because
* we set max_length bigger then necessary in other cases as well.
* the current solution is simpler and safer (bigger max_length is better then cutting out)
* Added Item_ref::set_properties
* Item_ref::Item_ref now expects to get in *item either
NULL - then fix_fields() will be called later or
ptr to Item it will refer to - then an equivalent of fix_fields() call is performed
The problem in 4.1 was the same as in 4.0 - fix_fields() not called for created Item_ref.
The fix is similar too - initialize Item_refs in ctor (but don't interfere with cases when
Item_ref is used by subselects).
CREATE DATABASE statement used the current database instead of the
database created when checking conditions for replication.
CREATE/DROP/ALTER DATABASE statements are now replicated based on
the manipulated database.
Now thd->mem_root is a pointer to thd->main_mem_root and THR_MALLOC is a pointer to thd->mem_root.
This gives us the following benefits:
- Allow us to easily detect if arena has already been swapped before (this fixes a bug in setup_conds() where arena was swaped twice in some cases)
- Faster swaps of arenas (as we don't have to copy the whole MEM_ROOT)
- We don't anymore have to call my_pthread_setspecific_ptr(THR_MALLOC,...) to change where memory is alloced. Now it's enough to set thd->mem_root
character set with NULL, @a should be latin2
after this query sequence:
SET @a=_latin2'string';
SET @a=NULL;
I.e. the second query should not change the charset
to the current default value, but should keep the
original value assigned during the first query.
In order to do it, we don't copy charset
from the argument if the argument is NULL
and the variable has previously been initialized.
constant with a column. The string is converted into the column
character set. It conversion doesn't lose data, then operation
is possible. Otherwise, give an error, as it was earlier.
crashes server." The fix makes Item_func_rand prepared-statements
aware plus it fixes the case when RAND is used in prepared
statements and replication is on (as well as several similar issues).
Until now we did not reset THD before every execution of a prepared
statement, so if some execution had set thd->time_zone_used
or thd->rand_used they would not be reset until next mysql_parse.
Some of post-review fixes done.
