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.

Put '-features=no%except' back into Solaris/x86 CXXFLAGS.

Conflicts:
  - scripts/CMakeLists.txt

Post-merge fix: remove leftovers from safemalloc removal.

applying bundle made for next-mr-bugfixing to trunk-bugfixing branch of the bug

applying bundle made for next-mr-bugfixing to trunk-bugfixing branch of the bug

Bug#47139: Test "merge" crashes in "embedded" run

Backport patch for Bug#47139

Backport from mysql-next-mr (5.6) to mysql-trunk (5.5)

Backport from mysql-next-mr (5.6) to mysql-trunk (5.5)

Backport from mysql-next-mr (5.6) to mysql-trunk (5.5)

Backport from mysql-next-mr (5.6) to mysql-trunk (5.5)

Backport from mysql-next-mr (5.6) to mysql-trunk (5.5)

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.

Backport from mysql-next-mr (5.6) to mysql-trunk (5.5)

Backport from mysql-next-mr (5.6) to mysql-trunk (5.5)

Backport from mysql-next-mr (5.6) to mysql-trunk (5.5)

Backport from mysql-next-mr (5.6) to mysql-trunk (5.5)

Backporting the fix from myql-next-mr (5.6) to mysql-trunk (5.5)

This fix is for cleanup, to resolve a remaining code review item.
Backport from mysql-next-mr (5.6) to mysql-trunk (5.5).

Fixed minor merge issues with #includes

Post-merge fix: adjust line numbers in pfs_upgrade test case
result given that mysql_system_tables_fix.sql was modified.

mysql_config. Those are mainly warning options intended
to monitor the server code and shouldn't be leaked to
client code.

Silence bogus aliasing warning through a pointer indirection. Also,
no need to check the return of a placement new.

Restore hack necessary to setup a libmysqld archive.

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.

Remove OS/2 specific code.

Remove QNX specific code.