added check_length optimization for I_S_NAME comparison

PB2 run uncovered issue that needs further analysis.

'CREATE TABLE IF NOT EXISTS ... SELECT' statement were causing 'CREATE
TEMPORARY TABLE ...' to be written to the binary log in row-based 
mode (a.k.a. RBR), when there was a temporary table with the same name.
Because the 'CREATE TABLE ... SELECT' statement was executed as 
'INSERT ... SELECT' into the temporary table. Since in RBR mode no 
other statements related to temporary tables are written into binary log,
this sometimes broke replication.

This patch changes behavior of 'CREATE TABLE [IF NOT EXISTS] ... SELECT ...'.
it ignores existence of temporary table with the 
same name as table being created and is interpreted
as attempt to create/insert into base table. This makes behavior of
'CREATE TABLE [IF NOT EXISTS] ... SELECT' consistent with
how ordinary 'CREATE TABLE' and 'CREATE TABLE ... LIKE' behave.

The optimizer must not continue executing the current query
if e.g. the storage engine reports an error.
This is somewhat hard to implement with Item::val_xxx()
because they do not have means to return error code.
This is why we need to check the thread's error state after
a call to one of the Item::val_xxx() methods.

Fixed store_key_item::copy_inner() to return an error state 
if an error happened during the call to Item::save_in_field() 
because it calls Item::val_xxx().
Also added similar checks to related places.

Added not_embedded to the new dbug_sync test file.

BUG#49481: RBR: MyISAM and bit fields may cause slave to stop on delete: 
cant find record
      
BUG#49482: RBR: Replication may break on deletes when MyISAM tables + 
char field are used

When using MyISAM tables, despite the fact that the null bit is
set for some fields, their old value is still in the row. This
can cause the comparison of records to fail when the slave is
doing an index or range scan.

We fix this by avoiding memcmp for MyISAM tables when comparing
records. Additionally, when comparing field by field, we first
check if both fields are not null and if so, then we compare
them. If just one field is null we return failure immediately. If
both fields are null, we move on to the next field.

Small fix in the test case. Changed the UNLOCK tables 
to happen after each insert.

In certain rare cases when a process was interrupted
during a FLUSH PRIVILEGES operation the diagnostic
area would be set to an error state but the function
responsible for the operation would still signal
success. This would lead to a debug assertion error
later on when the server would attempt to reset the
DA before sending the error message.

This patch fixes the issue by assuring that
reload_acl_and_cache() always fails if an error
condition is raised.

The second issue was that a KILL could cause
a console error message which referred to a DA
state without first making sure that such a
state existed.

This patch fixes this issue in two different
palces by first checking DA state before
fetching the error message.

 

Problem: When RAND() is binlogged in statement mode, the seed is
binlogged too, so the replication slave generates the same
sequence of random numbers. This makes replication work in many
cases, but not in all cases: the order of rows is not guaranteed
for, e.g., UPDATE or INSERT...SELECT statements, so the row data
will be different if master and slave retrieve the rows in
different orders.
Fix: Mark RAND() as unsafe. It will generate a warning if
binlog_format=STATEMENT and switch to row-logging if
binlog_format=ROW.

Problem: copying issuer's (or subject's) name tags into an internal
buffer from incoming stream we didn't check the buffer overflow. 
That may lead to memory overrun, crash etc.

Fix: ensure we don't overrun the buffer.

Note: there's no simple test case (exploit needed).

Selecting of the CONCAT_WS(...<PS parameter>...) result into
a user variable may return wrong data.

Item_func_concat_ws::val_str contains a number of memory
allocation-saving optimization tricks. After the fix
for bug 46815 the control flow has been changed to a
branch that is commented as "This is quite uncommon!":
one of places where we are trying to concatenate
strings inplace. However, that "uncommon" place
didn't care about PS parameters, that have another
trick in Item_sp_variable::val_str(): they use the
intermediate Item_sp_variable::str_value field,
where they may store a reference to an external
argument's buffer.

The Item_func_concat_ws::val_str function has been
modified to take into account val_str functions
(such as Item_sp_variable::val_str) that return a
pointer to an internal Item member variable that
may reference to a buffer provided.

MySQL handles the join syntax "JOIN ... USING( field1,
... )" and natural joins by building the same parse tree as
a corresponding join with an "ON t1.field1 = t2.field1 ..."
expression would produce. This parse tree was not cleaned up
properly in the following scenario. If a thread tries to
lock some tables and finds that the tables were dropped and
re-created while waiting for the lock, it cleans up column
references in the statement by means a per-statement free
list. But if the statement was part of a stored procedure,
column references on the stored procedure's free list weren't
cleaned up and thus contained pointers to freed objects.

Fixed by adding a call to clean up the current prepared
statement's free list.

This includes "MYSQL_U_SCORE_VERSION" in "configure.in".

- "release" starts from 1
- "level" ("m2", "rc", ...) is included in the RPM version.

but don't take the "tree name" change.

- "release" starts from 1
- "level" ("m2", "rc", ...) is included in the RPM version.

32bit builds with the --enable-assembler flag (enabled by default)
fail with an error message: undefined reference to `strmov_overlapp'.

Since the fix for bug 48866 we use a home-grown strmov function
instead of the ctpcpy function, but the source file for this
function was missed in the Makefile.am.

The strings/Makefile.am file has been modified to include strmov.c
file into ASSEMBLER_x86 and ASSEMBLER_sparc32 sections.

Recover the right contents of the index file at the end of the test case.

Manually deleteing one or more entries from 'master-bin.index', will
cause master infinitely loop to send one binlog file. 

When starting a dump session, master opens index file and search the binlog file
which is being requested by the slave. The position of the binlog file in the
index file is recorded. it will be used to find the next binlog file when current
binlog file has dumped completely. As only the position is used, it may
not get the correct file if some entries has been removed manually from the index file.
the master will reopen the current binlog file which has been dump completely
and redump it if it can not get the next binlog file's name from index file.
It obviously is a logical error.


Even though it is allowed to manually change index file,
but it is not recommended. so after this patch, master
sends a fatal error to slave and close the dump session if a new binlog file
has been generated and master can not get it from the index file.

Some improvements on the test case as suggested during review.

Fixed valgrind failure on PB2.

Fixed valgrind failure on PB2.

Fixed valgrind failure on PB2.

Fixed valgrind failure on PB2.