occasionally.

mysql_multi can call mysqld_safe. In doing this it's not changing the 
current working directory. This may cause confusion in the case where 
mysqld_multi is handling instances of servers of different versions 
and the current working directory is the installation directory of one 
of these servers.

Fixed by enhancing the meaning of basedir in [mysqldN] sections of 
mysqld_multi. If specified, mysqld_multi will change the current 
working directory to the basedir directory before starting the server 
in mysqld_multi ... start ... and then change it back to what it was.

      
Failure to allocate memory for the hash->array element,
caused hash_init to return without initializing the other
members of the hash. Thus although the dynamic array
buffer may be allocated at a later point in the code, the
incompletely initialized hash caused fatal failures.

This patch moves the initialization of the other members
of the hash above the array allocation, so that the usage
of this hash will not result in fatal failures.

      
Inconsistent behavior of session variable max_allowed_packet 
(and net_buffer_length); only assignment to the global variable 
has any effect, without this being obvious to the user.
      
The patch for Bug#22891 is backported to 5.0, making the two
session variables read-only. As this is a backport to GA 
software, the error used when trying to assign to the read-
only variable is ER_UNKNOWN_ERROR. The error message is the 
same as in 5.1+.

The problem: described in the bug report.
The fix:
--increase buffers where it's necessary
  (buffers which are used in stxnmov)
--decrease buffer lengths which are used

The problem was that a pthread.h header used by gcc did not
declare the pthread_setscheprio, yet the function is implemented
by the function is implemented, causing a autoconf check to pass
and compilation with C++ to fail. The solution is to add a
autoconf check to ensure that the function is properly declared.

Large transactions and statements may corrupt the binary log if the size of the
cache, which is set by the max_binlog_cache_size, is not enough to store the
the changes.

In a nutshell, to fix the bug, we save the position of the next character in the
cache before starting processing a statement. If there is a problem, we simply
restore the position thus removing any effect of the statement from the cache.
Unfortunately, to avoid corrupting the binary log, we may end up loosing changes
on non-transactional tables if they do not fit in the cache. In such cases, we
store an Incident_log_event in order to stop the slave and alert users that some
changes were not logged.

Precisely, for every non-transactional changes that do not fit into the cache,
we do the following:
  a) the statement is *not* logged
  b) an incident event is logged after committing/rolling back the transaction,
  if any. Note that if a failure happens before writing the incident event to
  the binary log, the slave will not stop and the master will not have reported
  any error.
  c) its respective statement gives an error

For transactional changes that do not fit into the cache, we do the following:
  a) the statement is *not* logged
  b) its respective statement gives an error

To work properly, this patch requires two additional things. Firstly, callers to
MYSQL_BIN_LOG::write and THD::binlog_query must handle any error returned and
take the appropriate actions such as undoing the effects of a statement. We
already changed some calls in the sql_insert.cc, sql_update.cc and sql_insert.cc
modules but the remaining calls spread all over the code should be handled in
BUG#37148. Secondly, statements must be either classified as DDL or DML because
DDLs that do not get into the cache must generate an incident event since they
cannot be rolled back.

Item_func_spatial_collection::val_str
        
When the concatenation function for geometry data collections
reads the binary data it was not rigorous in checking that there
is data available, leading to invalid reads and crashes.
Fixed by making checking stricter.

This patch corrects a misstake in the test case for bug patch 43658.

There was a race in the test case when the thread id was retrieved from the processlist.
The result was that the same thread id was signalled twice and one thread id wasn't
signalled at all.

The affected platforms appears to be limited to linux.

with gcc 4.3.2
      
Compiling MySQL with gcc 4.3.2 and later produces a number of 
warnings, many of which are new with the recent compiler
versions.
                  
This bug will be resolved in more than one patch to limit the
size of changesets. This is the second patch, fixing more
of the warnings.

This is a backport of BUG#43076.

      
The assertion in String::copy was added in order to avoid
valgrind errors when the destination was the same as the source.
Eased restriction to allow for the case when str == NULL.

to a test file that guarantees the presence of partition code