Conversion of a subquery to a semi-join is blocked when we have an
IN subquery predicate in the on_expr of an outer join. Currently this
scenario is handled but the cases when an IN subquery predicate is wrapped
inside a Item_in_optimizer item then this blocking is not done.
It was used for get_datetime_value() and for thd->is_error().
But in fact, get_datetime_value() never used thd argument, because the
cache ptr argument was NULL. And thd->is_error() check was not needed
at that place at all.
This change is a backport from 10.0 to 5.5 for:
1. The full patch for:
MDEV-4841 Wrong character set of ADDTIME() and DATE_ADD()
9adb6e991e
2. A small fragment of:
MDEV-5298 Illegal mix of collations on timestamp
03f6778d61
which overrides Item_temporal_hybrid_func::cmp_type(),
and adds a new line into cache_temporal_4265.result.
This is a backport of the patch for MDEV-9653 (fixed earlier in 10.1.13).
The code in Item_func_case::fix_length_and_dec() did not
calculate max_length and decimals properly.
In case of any numeric result (DECIMAL, REAL, INT) a generic method
Item_func_case::agg_num_lengths() was called, which could erroneously result
into a DECIMAL item with max_length==0 and decimals==0, so the constructor of
Field_new_decimals tried to create a field of DECIMAL(0,0) type,
which caused a crash.
Unlike Item_func_case, the code responsible for merging attributes in
Item_func_coalesce::fix_length_and_dec() works fine: it has specific execution
branches for all distinct numeric types and correctly creates a DECIMAL(1,0)
column instead of DECIMAL(0,0) for the same set of arguments.
The fix does the following:
- Moves the attribute merging code from Item_func_coalesce::fix_length_and_dec()
to a new method Item_func_hybrid_result_type::fix_attributes()
- Removes the wrong code from Item_func_case::fix_length_and_dec()
and reuses fix_attributes() in both Item_func_coalesce::fix_length_and_dec()
and Item_func_case::fix_length_and_dec()
- Fixes count_real_length() and count_decimal_length() to get an array
of Items as an argument, instead of using Item::args directly.
This is needed for Item_func_case::fix_length_and_dec().
- Moves methods Item_func::count_xxx_length() from "public" to "protected".
- Removes Item_func_case::agg_num_length(), as it's not used any more.
- Additionally removes Item_func_case::agg_str_length(),
as it also was not used (dead code).
GENERATED BY THE EXP() FUNCTION
When generating the error message for numeric overflow, pass a flag to
Item::print() that prevents it from expanding constant expressions and
parameters to the values they evaluate to.
For consistency, also pass the flag to Item::print() when
Item_func_spatial_collection::fix_length_and_dec() generates an error
message. It doesn't make any difference at the moment, since constant
expressions haven't been evaluated yet when this function is called.
MDEV-6789 segfault in Item_func_from_unixtime::get_date on updating table with virtual columns
* prohibit VALUES in partitioning expression
* prohibit user and system variables in virtual column expressions
* fix Item_func_date_format to cache locale (for %M/%W to return the same as MONTHNAME/DAYNAME)
* fix Item_func_from_unixtime to cache time_zone directly, not THD (and not to crash)
* added tests for other incorrectly allowed (in vcols) functions to see that they don't crash
Issue :
-------
This seems for some platform -(LONGLONG_MIN) is
not flagged as out of range.
Fix:
----
Fix is backported from mysql-5.6 bug 14314156.
Fixed by adding an explicit test for this value in
Item_func_neg::int_op().
sql/item_func.cc:
For some platforms we need special handling of
LONGLONG_MIN to guarantee overflow.
Issue :
-------
This seems for some platform -(LONGLONG_MIN) is
not flagged as out of range.
Fix:
----
Fix is backported from mysql-5.6 bug 14314156.
Fixed by adding an explicit test for this value in
Item_func_neg::int_op().
The bug caused a memory overwrite in the function update_ref_and_keys()
It happened due to a wrong value of SELECT_LEX::cond_count. This value
historically was calculated by the fix_fields method. Now the logic of
calling this method became too complicated and, as a result, this value
is calculated not always correctly.
The patch changes the way how and when the values of SELECT_LEX::cond_count
and of SELECT_LEX::between_count are calculated. The new code does it just at
the beginning of update_ref_and_keys().
Other fix of maybe_null problem and revert of revno: 3608 "MDEV-3873 & MDEV-3876 & MDEV-3912 : Wrong result (extra rows) with ALL subquery from a MERGE view."
STRING CONVERSION FUNCTIONS
Problem:
While executing the prepared statement, user variable is
set to memory which would be freed at the end of
execution.
If the statement is executed again, valgrind throws
error when accessing this pointer.
Analysis:
1. First time when Item_func_set_user_var::check is called,
memory is allocated for "value" to store the result.
(In the call to copy_if_not_alloced).
2. While sending the result, Item_func_set_user_var::check
is called again. But, this time, its called with
"use_result_field" set to true.
As a result, we call result_field->val_str(&value).
3. Here memory allocated for "value" gets freed. And "value"
gets set to "result_field", with "str_length" being that of
result_field's.
4. In the call to JOIN::cleanup, result_field's memory gets
freed as this is allocated in a chunk as part of the
temporary table which is needed to execute the query.
5. Next time, when execute of the same statement is called,
"value" will be set to memory which is already freed.
Valgrind error occurs as "str_length" is positive
(set at Step 3)
Note that user variables list is stored as part of the Lex object
in set_var_list. Hence the persistance across executions.
Solution:
Patch for Bug#11764371 fixed in mysql-5.6+ fixes this problem
as well.So backporting the same.
In the solution for Bug#11764371, we create another object of
user_var and repoint it to temp_table's field. As a result while
deleting the alloced buffer in Step 3, since the cloned object
does not own the buffer, deletion will not happen.
So at step 5 when we execute the statement second time, the
original object will be used and since deletion did not happen
valgrind will not complain about dangling pointer.
sql/item_func.h:
Add constructors.
sql/sql_select.cc:
Change user variable assignment functions to read from fields after
tables have been unlocked.
STRING CONVERSION FUNCTIONS
Problem:
While executing the prepared statement, user variable is
set to memory which would be freed at the end of
execution.
If the statement is executed again, valgrind throws
error when accessing this pointer.
Analysis:
1. First time when Item_func_set_user_var::check is called,
memory is allocated for "value" to store the result.
(In the call to copy_if_not_alloced).
2. While sending the result, Item_func_set_user_var::check
is called again. But, this time, its called with
"use_result_field" set to true.
As a result, we call result_field->val_str(&value).
3. Here memory allocated for "value" gets freed. And "value"
gets set to "result_field", with "str_length" being that of
result_field's.
4. In the call to JOIN::cleanup, result_field's memory gets
freed as this is allocated in a chunk as part of the
temporary table which is needed to execute the query.
5. Next time, when execute of the same statement is called,
"value" will be set to memory which is already freed.
Valgrind error occurs as "str_length" is positive
(set at Step 3)
Note that user variables list is stored as part of the Lex object
in set_var_list. Hence the persistance across executions.
Solution:
Patch for Bug#11764371 fixed in mysql-5.6+ fixes this problem
as well.So backporting the same.
In the solution for Bug#11764371, we create another object of
user_var and repoint it to temp_table's field. As a result while
deleting the alloced buffer in Step 3, since the cloned object
does not own the buffer, deletion will not happen.
So at step 5 when we execute the statement second time, the
original object will be used and since deletion did not happen
valgrind will not complain about dangling pointer.
sql/item_func.h:
Add constructors.
sql/sql_select.cc:
Change user variable assignment functions to read from fields after
tables have been unlocked.
STRING CONVERSION FUNCTIONS
Problem:
While executing the prepared statement, user variable is
set to memory which would be freed at the end of
execution.
If the statement is executed again, valgrind throws
error when accessing this pointer.
Analysis:
1. First time when Item_func_set_user_var::check is called,
memory is allocated for "value" to store the result.
(In the call to copy_if_not_alloced).
2. While sending the result, Item_func_set_user_var::check
is called again. But, this time, its called with
"use_result_field" set to true.
As a result, we call result_field->val_str(&value).
3. Here memory allocated for "value" gets freed. And "value"
gets set to "result_field", with "str_length" being that of
result_field's.
4. In the call to JOIN::cleanup, result_field's memory gets
freed as this is allocated in a chunk as part of the
temporary table which is needed to execute the query.
5. Next time, when execute of the same statement is called,
"value" will be set to memory which is already freed.
Valgrind error occurs as "str_length" is positive
(set at Step 3)
Note that user variables list is stored as part of the Lex object
in set_var_list. Hence the persistance across executions.
Solution:
Patch for Bug#11764371 fixed in mysql-5.6+ fixes this problem
as well.So backporting the same.
In the solution for Bug#11764371, we create another object of
user_var and repoint it to temp_table's field. As a result while
deleting the alloced buffer in Step 3, since the cloned object
does not own the buffer, deletion will not happen.
So at step 5 when we execute the statement second time, the
original object will be used and since deletion did not happen
valgrind will not complain about dangling pointer.
