require O(#scans) memory

When an index merge operation was restarted, it would
re-allocate the Unique object controlling the duplicate row
ID elimination. Fixed by making the Unique object a member
of QUICK_INDEX_MERGE_SELECT and thus reusing it throughout
the lifetime of this object.

file .\filesort.cc, line 149 (part II)

Problem: the server didn't disregard sort order 
for some zero length tuples.

Fix: skip sort order in such a case 
(zero length NOT NULL string functions).

Incorrect handling of NULL arguments could lead to a crash on
the IN or CASE operations when either NULL arguments were
passed explicitly as arguments (IN) or implicitly generated by
the WITH ROLLUP modifier (both IN and CASE).

Item_func_case::find_item() assumed all necessary comparators
to be instantiated in fix_length_and_dec(). However, in the
presence of WITH ROLLUP modifier, arguments could be
substituted with an Item_null leading to an "unexpected"
STRING_RESULT comparator being invoked.

In addition to the problem identical to the above,
Item_func_in::val_int() could crash even with explicitly passed
NULL arguments due to an optimization in fix_length_and_dec()
leading to NULL arguments being ignored during comparators
creation.

In process of record search it is not taken into account
that inital quick->file->ref value could be inapplicable
to range interval. After proper row is found this value is
stored into the record buffer and later the record is
filtered out at condition evaluation stage.
The fix is store a refernce of found row to the handler ref field.

Problem: a flaw (derefencing a NULL pointer) in the LIKE optimization
code may lead to a server crash in some rare cases.

Fix: check the pointer before its dereferencing.

mysql_client_binlog_statement

Problem: server may read from unassigned memory performing
"wrong" BINLOG queries.

Fix: never read from unassigned memory.

line exceeds the limit

Upmerge the fix from 5.0 to 5.1

           line exceeds the limit

The number and/or names of our files for the main test suite
(contents of "mysql-test/t/") now exceeds the command line
length limit on AIX.
Solve the problem by using separate "cp" commands for the
various file name extensions.

This is the fix for 5.1, where only the behaviour on upgrade is changed:
If the server was stopped when the upgrade begins, we assume the
administrator is taking manual action, so we do not start the (new)
server at the end of the upgrade.
We still install the start/stop script, so it will be started on reboot.

root cause of 52208 resulted in another test failure
in 5.1.

Reorder code breaks when finding tests skipped due to --skip-rpl etc.
Add simple test that master_opt is non-empty

Kill mysqltest and call mtr_kill_leftovers() before terminating

In Prepared_statement::prepare() bail out as soon as
parser_state.init() fails, trying to continue leads to crashes.

conflicts:
   conflict      sql/sql_parse.cc

Item*) at opt_sum.cc:305
      
Queries applying MIN/MAX functions to indexed columns are
optimized to read directly from the index if all key parts
of the index preceding the aggregated key part are bound to
constants by the WHERE clause. A prefix length is also
produced, equal to the total length of the bound key
parts. If the aggregated column itself is bound to a
constant, however, it is also included in the prefix.

Such full search keys are read as closed intervals for
reasons beyond the scope of this bug. However, the procedure
missed one case where a key part meant for use as range
endpoint was being overwritten with a NULL value destined
for equality checking. In this case the key part was
overwritten but the range flag remained, causing open
interval reading to be performed.

Bug was fixed by adding more stringent checking to the
search key building procedure (matching_cond) and never
allow overwrites of range predicates with non-range
predicates.

An assertion was added to make sure open intervals are never
used with full search keys.

            strict aliasing violations.

One somewhat major source of strict-aliasing violations and
related warnings is the SQL_LIST structure. For example,
consider its member function `link_in_list` which takes
a pointer to pointer of type T (any type) as a pointer to
pointer to unsigned char. Dereferencing this pointer, which
is done to reset the next field, violates strict-aliasing
rules and might cause problems for surrounding code that
uses the next field of the object being added to the list.

The solution is to use templates to parametrize the SQL_LIST
structure in order to deference the pointers with compatible
types. As a side bonus, it becomes possible to remove quite
a few casts related to acessing data members of SQL_LIST.

           strict aliasing violations.

Essentially, the problem is that large parts of the server were
developed in simpler times (last decades, pre C99 standard) when
strict aliasing and compilers supporting such optimizations were
rare to non-existent. Thus, when compiling the server with a modern
compiler that uses strict aliasing rules to perform optimizations,
there are several places in the code that might trigger undefined
behavior.

As evinced by some recent bugs, GCC does a somewhat good of job
misoptimizing such code, but on the other hand also gives warnings
about suspicious code. One problem is that the warnings aren't
always accurate, yet we can't afford to just shut them off as we
might miss real cases. False-positive cases are aggravated mostly
by casts that are likely to trigger undefined behavior.

The solution is to start a cleanup process focused on fixing and
reducing the amount of strict-aliasing related warnings produced
by GCC and others compilers. A good deal of noise reduction can
be achieved by just removing useless casts that are product of
historical cruft and are likely to trigger undefined behavior if
dereferenced.

The bug was caused by buffered output. Flushing resolved it.
We still recommend to allways call plan().
  
Also fix some compile warnings (formal parameter different from declaration)

Addendum: Work around a compilation failure on Windows due to
          windows.h not being added to the global namespace.

Problem: the server missed the fact that one can read from 
2 indexes alternately using HANDLER interface.

Fix: check if the same (initialized) index is involved
reading next/prev values from the index.

The problem was that the bundled yaSSL library was being built
without thread safety support regardless of the thread safeness
of the compoments linked with it.

The solution is to enable yaSSL thread safety support if any
component (server or client) is to be built with thread support.

Also, generate new certificates for yaSSL's test suite.

Logging slow stored procedures caused the slow log to write 
very large lock times. The lock times was a result of a 
negative number being cast to an unsigned integer.
The reason the lock time appeard negative was because 
one of the measurements points was reset after execution
causing it to change order with the start time of the 
statement.
      
This bug is related to bug 47905 which in turn was 
introduced because of a joint fix for 12480,12481,12482 and 11587.

The fix is to only reset the start_time before any statement
execution in a SP while not resetting start_utime or
utime_after_lock which are used for measuring the 
performance of the SP. Start_time is used to set the
timestamp on the replication event which controlls how
the slave interprets time functions like NOW().

The problem is in the Item_func_isnull::update_used_tables() function,
bracket is at the wrong place. Because of that isnull item erroneously
is treated as const item. The fix is to set brackets in the right place.

when an out-of-supported-range date is detected.

NET::skip_big_packet isn't defined for the embedded server,
hide it in such a case.