The reason of the bug is in that `get_var_with_binlog' performs missed
assingment of
the variables as side-effect. Doing that it eventually calls
`free_underlaid_joins' to pass as an argument `thd->lex->select_lex' of the lex
which belongs to the user query, not
to one which is emulated i.e SET @var1:=NULL.
`get_var_with_binlog' is refined to supply a temporary lex to sql_set_variables's stack.
used
In a simple queries a result of the GROUP_CONCAT() function was always of
varchar type.
But if length of GROUP_CONCAT() result is greater than 512 chars and temporary
table is used during select then the result is converted to blob, due to
policy to not to store fields longer than 512 chars in tmp table as varchar
fields.
In order to provide consistent behaviour, result of GROUP_CONCAT() now
will always be converted to blob if it is longer than 512 chars.
Item_func_group_concat::field_type() is modified accordingly.
Removed wrong fix for bug #14009 (use of abs() on null value causes problems with filesort)
Mark that add_time(), time_diff() and str_to_date() can return null values
Adding test
item_sum.cc:
Adding a call for collation/charset aggregation,
to collect attributes from the arguments. The actual bug fix.
item_func.h, item_func.cc, item.h, item.cc:
- Removing collation aggrgation functions from Item_func class
in item.cc, and adding it as non-class functions in item.cc
to be able to reuse this code for group_concat.
- Adding replacement for these functions into Item_func class
as wrappers for moved functions, to minizize patch size,
of system vars at PREPARE time": implement a special Item
to handle system variables. This item substitutes itself with
a basic constant containing variable value at fix_fields.
Ensure that 'null_value' is not accessed before val() is called in FIELD() functions
Fixed initialization of key maps. This fixes some problems with keys when you have more than 64 keys
Fixed that ROLLUP don't always create a temporary table. This fix ensures that func_gconcat.test results are now predictable
set_var.cc:
variables.result
variables.test
Bug #10904 Illegal mix of collations between a system variable and a constant
Changing coercibility of system variables to SYSCONST,
to be the same with USER(), DATABASE(), etc.
records if prepared statements is used".
This fix changes equality evaluation method of basic constants from
by-name to by-value, thus effectively enabling use of parameter markers
in some optimizations (constants propagation, evaluation of possible
keys for query).
(aka "deinit is not called when calling udf from trigger").
We should call udf_deinit() function during cleanup phase after prepared
(or ordinary) statement execution instead of calling it from Item's
desctructor.
No test case is provided since it is hard to test UDF's from our test
suite.
Produce warnings of wrong cast of strings to signed/unsigned.
Don't block not resolved IP's if DNS server is down (Bug #8467)
Fix compiler problems with MinGW (Bug #8872)
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()
