Checking for NULL before calling the val_xxx()
methods only checks for such arguments that are
known to be NULLs at compile time.
The arguments that may or may not contain
NULLs (e.g. function calls and possibly others)
are not checked at all.
Fixed by first calling the val_xxx() method and
then checking for null in SEC_TO_TIME().
In addition QUARTER() was not returning 0 (as all the
val_int() functions do when processing a NULL value).
Objects of the classes Item_func_is_not_null_test and Item_func_trig_cond
must be transparent for the method Item::split_sum_func2 as these classes
are pure helpers. It means that the method Item::split_sum_func2 should
look at those objects as at pure wrappers.
The bug report has demonstrated the following two problems.
1. If an ORDER/GROUP BY list includes a constant expression being
optimized away and, at the same time, containing single-row
subselects that return more that one row, no error is reported.
Strictly speaking the standard allows to ignore error in this case.
Yet, now a corresponding fatal error is reported in this case.
2. If a query requires sorting by expressions containing single-row
subselects that, however, return more than one row, then the execution
of the query may cause a server crash.
To fix this some code has been added that blocks execution of a subselect
item in case of a fatal error in the method Item_subselect::exec.
on duplicate key".
INSERT ... SELECT ... ON DUPLICATE KEY UPDATE which was used in
stored routine or as prepared statement and which in its ON DUPLICATE
KEY clause erroneously tried to assign value to a column mentioned only
in its SELECT part was properly emitting error on the first execution
but succeeded on the second and following executions.
Code which is responsible for name resolution of fields mentioned in
UPDATE clause (e.g. see select_insert::prepare()) modifies table list
and Name_resolution_context used in this process. It uses
Name_resolution_context_state::save_state/restore_state() to revert
these modifications. Unfortunately those two methods failed to revert
properly modifications to TABLE_LIST::next_name_resolution_table
and this broke name resolution process for successive executions.
This patch fixes Name_resolution_context_state::save_state/restore_state()
in such way that it properly handles TABLE_LIST::next_name_resolution_table.
aim is to:
a) if set_connect_timeout called, timeout connect attempt (for retry on
next call) after timeout period
b) preserve existing blocking behaviour otherwise (for, e.g. mgmapi)
Related to customer issue with long time deleting ndb_cluster_connection
object. believe we're hanging on the connect(2) call until timeout (when
we then realise we should exit the thread).
