When there is an error executing EXISTS predicates they return NULL as their string
or decimal value but don't set the NULL value flag.
Fixed by returning 0 (as a decimal or a string) on error exectuting the subquery.
Note that we can't return NULL as EXISTS is not supposed to return NULL.

Bug#12093 "SP not found on second PS execution if another thread 
drops other SP in between" and
Bug#21294 "executing a prepared statement that executes a stored 
function which was recreat"

Stored functions are resolved at prepared statement prepare only.
If someone flushes the stored functions cache between prepare and
execute, execution fails.

The fix is to detect the situation of the cache flush and automatically
reprepare the prepared statement after it.

This bug has been fixed in two slightly different ways in
6.0-rpl and {5.1,6.0}-bugteam. To avoid future merge
problems, I'm now copying the 6.0-rpl fix to 5.1-bugteam.

The previous fix for the bug was incomplete. The test failed
because t2 did not exist on the slave (since the slave was
lagging) when the
wait_condition was executed. Fixed by inserting
sync_slave_with_master just after t2 was created.

Test was failing due to the addition of a '\x05' character in result sets
Latest builds of the server have shown this problem to have disappeared.
Removing code within the test that disables the test on Mac OS X.

Recommit due to tree error on earlier, approved patch.

Problem: rpl_switch_stm_row_mixed did not wait until row events generated by
INSERT DELAYED were written to the master binlog before it synchronized slave
with master. This caused sporadic errors where these rows were missing on
slave.
Fix: wait until all rows appear on the slave.
This is a backport, applying the same to 5.1-bugteam as was previously
applied to 6.0-rpl

Differences in 5.1: include "/etc/mysql/" in include directories; no OS/2 support.

                  InnoDB table, where all selected columns
                  belong to the same unique index key, returns
                  incorrect results

Server executes some queries via QUICK_GROUP_MIN_MAX_SELECT
(MIN/MAX optimization for queries with GROUP BY or DISTINCT
clause) and that optimization implies loose index scan, so all
grouping is done by the QUICK_GROUP_MIN_MAX_SELECT::get_next
method.

The server does not set the precomputed_group_by flag for some
QUICK_GROUP_MIN_MAX_SELECT queries and duplicates grouping by
call to the end_send_group function.

Fix: when the test_if_skip_sort_order function selects loose 
index scan as a best way to satisfy an ORDER BY/GROUP BY type
of query, the precomputed_group_by flag has been set to use 
end_send/end_write functions instead of end_send_group/
end_write_group functions.

      
Bug#35658 (An empty binary value leads to mysqld crash)
        
Before this fix, the following token
  b''
caused the parser to crash when reading the binary value from the empty string.
The crash was caused by:
  ptr+= max_length - 1;
because max_length is unsigned and was 0, causing an overflow.
        
With this fix, an empty binary literal b'' is parsed as a binary value 0,
in Item_bin_string.

Bug#35658 (An empty binary value leads to mysqld crash)
  
Before this fix, the following token
  b''
caused the parser to crash when reading the binary value from the empty string.
The crash was caused by:
  ptr+= max_length - 1;
because max_length is unsigned and was 0, causing an overflow.
  
With this fix, an empty binary literal b'' is parsed as a binary value 0,
in Item_bin_string.

Bug#37492 timing bug in subselect.test
+ similar weaknesses found during testing
+ replace error numbers by error names

Normalize directory names before adding them to default_directories.

Bug#35480: BOM detection code crashes mysql CLI with zero-sized input
      
MySQL client crashed if no input was passed to it.

Bug#33812: mysql client incorrectly parsing DELIMITER
      
Remove unnecessary and incorrect code that tried
to pull delimiter commands out of the middle of
statements.

            as a commentary

mysql client has been modified to interpret EOL after
standalone -- commentary strings like whitespace
character (according to
http://dev.mysql.com/doc/refman/5.0/en/ansi-diff-comments.html)

Remove unnecessary and incorrect code that tried
to pull delimiter commands out of the middle of
statements.

                        
      The crash appeared to be a result of allocating an instance of Discrete_interval 
      automatically that that was referred in out-of-declaration scope.
                        
      Fixed with correcting backing up and restoring scheme of
      auto_inc_intervals_forced, introduced by bug#33029, by means of shallow copying;
      added simulation code that forces executing those fixes of the former bug that
      targeted at master-and-slave having incompatible bug#33029-prone versions.

Another problem is that the backtrace facility wasn't being
enabled for non-Linux targets even if the target OS has the
backtrace functions. Also, the stacktrace functions inside
mysqltest were being used without proper checks for their
presence in the build.

                  replicated correctly between machines with
                  mixed endiannes

On a slow environment like valgrind the test is vulnerable
because it does not check if slave has stopped at time
of the new session is requested `start slave;' -- disabling
test till it is fixed.