Bug#11764671  57533: UNINITIALISED VALUES IN COPY_AND_CONVERT (SQL_STRING.CC) WITH CERTAIN CHA
When ROUND evaluates decimal result it uses Item::decimal
value as fraction value for the result. In some cases
Item::decimal is greater than real result fraction value
and uninitialised memory of result(decimal) buffer can be
used in further calculations. Issue is introduced by
Bug33143 fix. The fix is to remove erroneous assignment.

Update test case

.0

The bug was fixed by the patch for bug number BUG 11763109 - 55779: SELECT
DOES NOT WORK PROPERLY IN MYSQL SERVER VERSION "5.1.42 SUSE MYSQL (Exact same
fix as was proposed for this bug.) Since the motivation for the two bug
reports was completely different, however, it still makes sense to push the
test case.

This patch contains only the test case.

Some multibyte sequences could be considered by my_mbcharlen() functions
as multibyte character but more exact my_ismbchar() does not think so.
In such a case this multibyte sequences is pushed into 'stack' buffer which
is too small to accommodate the sequence.
The fix is to allocate stack buffer in
compliance with max character length.

Instead of just filtering space, filter white space (\s)
I left the default.experimental file as is, with tabs.

Valgrind warnings were caused by comparing index values to an un-initialized field.

Fix for --vs-config applied
Find.pm incorrectly tested an unitialized local variable instead
  of the global, corrected.
Find.pm is also wrong in 5.5: uses a non-existent global variable. Fix when
  merging up.

There are two problems with ANALYSE():

1. Memory leak 
   it happens because do_select() can overwrite
   JOIN::procedure field(with zero value in our case) and
   JOIN destructor don't free the memory allocated for
   JOIN::procedure. The fix is to save original JOIN::procedure
   before do_select() call and restore it after do_select
   execution.

2. Wrong result
   If ANALYSE() procedure is used for the statement with LIMIT clause
   it could retrun empty result set. It happens because of missing 
   analyse::end_of_records() call. First end_send() function call
   returns NESTED_LOOP_QUERY_LIMIT and second call of end_send() with
   end_of_records flag enabled does not happen. The fix is to return
   NESTED_LOOP_OK from end_send() if procedure is active.

When we create temporary result table for UNION
incorrect max_length for YEAR field is used and
it leads to incorrect field value and incorrect
result string length as YEAR field value calculation
depends on field length.
The fix is to use underlying item max_length for
Item_sum_hybrid::max_length intialization.

Valgrind warning happens due to early null values check
in Item_func_in::fix_length_and_dec(before item evaluation).
As result null value items with uninitialized values are
placed into array and it leads to valgrind warnings during
value array sorting.
The fix is to check null value after item evaluation, item
is evaluated in in_array::set() method.

Select from a view with the underlying HAVING clause failed with a
message: "1356: View '...' references invalid table(s) or column(s)
or function(s) or definer/invoker of view lack rights to use them"

The bug is a regression of the fix for bug 11750328 - 40825 (similar
case, but the HAVING cause references an aliased field).
In the old fix for bug 40825 the Item_field::name_length value has
been used in place of the real length of Item_field::name. However,
in some cases Item_field::name_length is not in sync with the
actual name length (TODO: combine name and name_length into a
solid String field).

The Item_ref::print() method has been modified to calculate actual
name length every time.

               create_schema if auto-generate-sql also set.

mysqlslap uses a schema to run its tests on and later
drops it if auto-generate-sql is used. This can be a
problem, if the schema is an already existing one.

If create-schema is used with auto-generate-sql option,
mysqlslap while performing the cleanup, drops the specified
database.

Fixed by introducing an option --no-drop, which, if used,
will prevent the dropping of schema at the end of the test.

   on lctn2 systems

There was a local variable in get_all_tables() to store the 
"original" value of the database name as it can get lowercased
depending on the lower_case_table_name value.
get_all_tables() iterates over database names and for each 
database iterates over the tables in it.
The "original" db name was assigned in the table names loop.
Thus the first table is ok, but the second and subsequent tables
get the lowercased name from processing the first table.
Fixed by moving the assignment of the original database name
from the inner (table name) to the outer (database name) loop.
Test suite added.

In the string context the MIN() and MAX() functions don't take
into account the unsignedness of the UNSIGNED BIGINT argument
column.

I.e.:
        CREATE TABLE t1 (a BIGINT UNSIGNED);
        INSERT INTO t1 VALUES (18446668621106209655);
        SELECT CONCAT(MAX(a)) FROM t1;

returns -75452603341961.

The patch fixes a build problem on MacOSX, where
the compiler complains about unused parameters.

sync_array_print_long_waits(): Return the longest waiting thread ID
and the longest waited-for lock. Only if those remain unchanged
between calls in srv_error_monitor_thread(), increment
fatal_cnt. Otherwise, reset fatal_cnt.

Background: There is a built-in watchdog in InnoDB whose purpose is to
kill the server when some thread is stuck waiting for a mutex or
rw-lock. Before this fix, the logic was flawed.

The function sync_array_print_long_waits() returns TRUE if it finds a
lock wait that exceeds 10 minutes (srv_fatal_semaphore_wait_threshold).
The function srv_error_monitor_thread() will kill the server if this
happens 10 times in a row (fatal_cnt reaches 10), checked every 30
seconds. This is wrong, because this situation does not mean that the
server is hung. If the server is very busy for a little over 15
minutes, it will be killed.

Consider this example. Thread T1 is waiting for mutex M. Some time
later, threads T2..Tn start waiting for the same mutex M. If T1 keeps
waiting for 600 seconds, fatal_cnt will be incremented to 1. So far,
so good. Now, if M is granted to T1, the server was obviously not
stuck. But, T2..Tn keeps waiting, and their wait time will be longer
than 600 seconds. If 5 minutes later, some Tn has still been waiting
for more than 10 minutes for the mutex M, the server can be killed,
even though it is not stuck.

rb:622 approved by Jimmy Yang

Valgrind warning happens due to missing NULL value check in
Item::get_date. The fix is to add this check.

Valgrind warning happens because null values check happens too late
in Item_func_month::val_str(after result string calculation).The fix
is to check null value before result string calculation.

ASSERTION TABLE->DB_STAT FAILED IN
SQL_BASE.CC::OPEN_TABLE() DURING I_S Q

This assert could be triggered if a statement requiring a name
lock on a table (e.g. DROP TRIGGER) executed concurrently
with an I_S query which also used the table.

One connection first started an I_S query that opened a given table.
Then another connection started a statement requiring a name lock
on the same table. This statement was blocked since the table was
in use by the I_S query. When the I_S query resumed and tried to
open the table again as part of get_all_tables(), it would encounter
a table instance with an old version number representing the pending
name lock. Since I_S queries ignore version checks and thus pending
name locks, it would try to continue. This caused it to encounter
the assert. The assert checked that the TABLE instance found with a
different version, was a real, open table. However, since this TABLE
instance instead represented a pending name lock, the check would
fail and trigger the assert.

This patch fixes the problem by removing the assert. It is ok for
TABLE::db_stat to be 0 in this case since the TABLE instance can
represent a pending name lock.

Test case added to lock_sync.test.

Issue:
======
Test case Correction for bug#11751148.

Valgrind warning happens due to missing NULL value check in
Item_func::val_decimal. The fix is to add this check.

Valgrind warning happens due to uninitialized cached_format_type field
which is used later in Item_func_str_to_date::val_str method.
The fix is to init cached_format_type field.