This bug is a design flaw of the fix for the bug#33546. It assumed that an
item can be used only in one comparison context, but actually it isn't the
case. Item_cache_datetime is used to store result for MIX/MAX aggregate
functions. Because Arg_comparator always compares datetime values as INTs when
possible the Item_cache_datetime most time caches only INT value. But
since all datetime values has STRING result type MIN/MAX functions are asked
for a STRING value when the result is being sent to a client. The
Item_cache_datetime was designed to avoid conversions and get INT/STRING
values from an underlying item, but at the moment the values is asked
underlying item doesn't hold it anymore thus wrong result is returned.
Beside that MIN/MAX aggregate functions was wrongly initializing cached result
and this led to a wrong result.
The Item::has_compatible_context helper function is added. It checks whether
this and given items has the same comparison context or can be compared as
DATETIME values by Arg_comparator. The equality propagation optimization is
adjusted to take into account that items which being compared as DATETIME
can have different comparison contexts.
The Item_cache_datetime now converts cached INT value to a correct STRING
DATETIME value by means of number_to_datetime & my_TIME_to_str functions.
The Arg_comparator::set_cmp_context_for_datetime helper function is added.
It sets comparison context of items being compared as DATETIMEs to INT if
items will be compared as longlong.
The Item_sum_hybrid::setup function now correctly initializes its result
value.
In order to avoid unnecessary conversions Item_sum_hybrid now states that it
can provide correct longlong value if the item being aggregated can do it
too.
mysql-test/r/group_by.result:
Added a test case for the bug#49771.
sql/item.cc:
Bug#49771: Incorrect MIN/MAX for date/time values.
The equality propagation mechanism is adjusted to take into account that
items which being compared as DATETIME can have different comparison
contexts.
The Item_cache_datetime now converts cached INT value to a correct STRING
DATETIME/TIME value.
sql/item.h:
Bug#49771: Incorrect MIN/MAX for date/time values.
The Item::has_compatible_context helper function is added. It checks whether
this and given items has the same comparison context or can be compared as
DATETIME values by Arg_comparator.
Added Item_cache::clear helper function.
sql/item_cmpfunc.cc:
Bug#49771: Incorrect MIN/MAX for date/time values.
The Arg_comparator::set_cmp_func now sets the correct comparison context
for items being compared as DATETIME values.
sql/item_cmpfunc.h:
Bug#49771: Incorrect MIN/MAX for date/time values.
The Arg_comparator::set_cmp_context_for_datetime helper function is added.
It sets comparison context of items being compared as DATETIMEs to INT if
items will be compared as longlong.
sql/item_sum.cc:
Bug#49771: Incorrect MIN/MAX for date/time values.
The Item_sum_hybrid::setup function now correctly initializes its result
value.
sql/item_sum.h:
Bug#49771: Incorrect MIN/MAX for date/time values.
In order to avoid unnecessary conversions Item_sum_hybrid now states that it
can provide correct longlong value if the item being aggregated can do it
too.
This assert checks that the server does not try to send OK to the
client if there has been some error during processing. This is done
to make sure that the error is in fact sent to the client.
The problem was that view errors during processing of WHERE conditions
in UPDATE statements where not detected by the update code. It therefore
tried to send OK to the client, triggering the assert.
The bug was only noticeable in debug builds.
This patch fixes the problem by making sure that the update code
checks for errors during condition processing and acts accordingly.
Remove --loose-skip-innodb from startup options
This is a simple backport of change done in WL #5349
Same as shown as "temporary fix", cherry picked to -mtr branch
of the "embedded" server
Problem: mysqltest_embedded failed to load ha_innodb_plugin library
on some platforms (due to some unresolved references).
Fix: on FreeBSD use -export-dynamic flag building mysqltest_embedded.
That allows to use its global symbols to resolve references in the
dynamically loaded plugin library.
libmysqld/examples/Makefile.am:
Fix for bug #50667: The InnoDB plugin prevents initialization
of the "embedded" server
- use -export-dynamic (on FreeBSD/DragonFly) building
mysqltest_embedded to allow using its global symbols
to resolve references in the dynamically loaded plugin libraries.
Fix compiler warnings due to: a mismatch in the prototypes for
check_access and implicit conversions from double to ulonglong
and vice-versa.
mysys/my_getopt.c:
Explicit conversion from ulonglong to double. Might need to
be tweaked in the future.
sql/sql_parse.h:
Make prototype equal to the case when not compiling under embedded.
sql/sys_vars.cc:
Explicit conversion from ulonglong to double. Destination var
is a ulonglong.
sql/sys_vars.h:
Explicit conversion from ulonglong to double. Might need to
be tweaked in the future.
