There are two problems:
1. In simplify_joins function we calculate table dependencies. If STRAIGHT_JOIN hint
is used for whole SELECT we do not count it and as result some dependendecies
might be lost. It leads to incorrect table order which is returned by
join_tab_cmp_straight() function.
2. make_join_statistics() calculate the transitive closure for relations a particular
JOIN_TAB is 'dependent on'.
We aggregate the dependent table_map of a JOIN_TAB by adding dependencies from other
tables which we depend on. However, this may also cause new dependencies to be
available after we have completed processing a certain JOIN_TAB.
Both these problems affect condition pushdown and as result condition might be pushed
into wrong table which leads to crash or even omitted which leads to wrong result.
The fix:
1. Use modified 'transitive closure' algorithm provided by Ole John Aske
2. Update table dependences in simplify_joins according to 
   global STRAIGHT_JOIN hint.
Note: the patch also fixes bugs 46091 & 51492

Null-merged patch for bug 53907.

Conflicts:

   conflict      sql/sql_parse.cc

Removed misleading comments.

             bitmap_is_set(table->read_set, field_index))

UPDATE on an InnoDB table modifying the same index that is used
to satisfy the WHERE condition could trigger a debug assertion
under some circumstances.

Since for engines with the HA_PRIMARY_KEY_IN_READ_INDEX flag
set results of an index scan on a secondary index are appended
by the primary key value, if a query involves only columns from
the primary key and a secondary index, the latter is considered
to be covering.

That tricks mysql_update() to mark for reading only columns
from the secondary index when it does an index scan to retrieve
rows to update in case a part of that key is also being
updated. However, there may be other columns in WHERE that are
part of the primary key, but not the secondary one.

What we actually want to do in this case is to add index
columns to the existing WHERE columns bitmap rather than
replace it.

Problem: one with SELECT privilege on some table may dump other table
performing COM_TABLE_DUMP command due to missed check of the table name.

Fix: check the table name.

This fixes a recently introduced regression, where a variable is
not defined for the embedded server. Although the embedded server
is not supported in 5.0, make it at least compile.

OpenBSD releases.

Apply patch from Brad Smith, thanks!

in mysql-trunk-merge).

There were two problems:
  - a mistake during merge of a patch for Bug 52629 from 5.1;
  - MTR treated auxilary output of newer valgrind as an error.

The fixes are:
  - Fix merge error;
  - Teach MTR to skip 'HEAP summary' section of valgrind output.

Some of the test cases reference to binlog position and
these position numbers are written into result explicitly.
It is difficult to maintain if log event format changes. 

There are a couple of cases explicit position number appears, 
we handle them in different ways
A. 'CHANGE MASTER ...' with MASTER_LOG_POS or/and RELAY_LOG_POS options
   Use --replace_result to mask them.
B. 'SHOW BINLOG EVENT ...'
   Replaced by show_binlog_events.inc or wait_for_binlog_event.inc. 
   show_binlog_events.inc file's function is enhanced by given
   $binlog_file and $binlog_limit.
C. 'SHOW SLAVE STATUS', 'show_slave_status.inc' and 'show_slave_status2.inc'
   For the test cases just care a few items in the result of 'SHOW SLAVE STATUS',
   only the items related to each test case are showed.
   'show_slave_status.inc' is rebuild, only the given items in $status_items
   will be showed.
   'check_slave_is_running.inc' and 'check_slave_no_error.inc'
   and 'check_slave_param.inc' are auxiliary files helping
   to show running status and error information easily.

Conflicts:

   conflict      Makefile.am
   conflict      mysql-test/suite/rpl/r/rpl_stm_mixing_engines.result
   conflict      mysql-test/suite/rpl/t/rpl_tmp_table_and_DDL.test
   conflict      sql/opt_sum.cc
   conflict      sql/set_var.cc
   conflict      sql/sql_base.cc
   conflict      sql/sql_priv.h
   conflict      sql/sql_show.cc

            data directory name command

The check_db_name function has been modified to validate tails of
#mysql50#-prefixed database names for compliance with MySQL 5.0
database name encoding rules (the check_table_name function call
has been reused).

Problem: The test case mysqldump reads a file that must
be world-readable. The test did not force the file to be
world-readable, so if the tree was branched with a umask
of 0077, the test would fail.
Fix: chmod the file.

Conflicts:
  - mysql-test/r/partition.result
  - mysql-test/r/variables_debug.result
  - mysql-test/t/partition.test
  - mysql-test/t/variables_debug.test

Server crashes on 64bit linux with 'double free or corruption'
message, on 32bit mysql-test-run silently fails on bootstrap
stage. The problem is that FreeState() is called twice
for init_settings struct in _db_end_ function.
The fix is to remove superfluous FreeState() call.
Additional fix:
fixed discrepancy of result file when
debug & valgrind options are enabled
for MTR.

(make relies GNU extentions). The patch was partially
backport from 6.0.

Original comment:
bug#30708: make relies GNU extensions.  Now that we no longer use
BitKeeper we can safely remove the SCCS handling with no loss of
functionality.

from 6.0 to trunk-bugfixing.

Bug #50087 Interval arithmetic for Event_queue_element is not portable.

Subtraction of two unsigned months yielded a (very large) positive value.
Conversion of this to a signed value was not necessarily well defined.
              
Solution: do the subtraction on signed values.

Analysis showed that in case of accessing I_S table
ROUTINES we perform unnecessary allocations
with get_field() function for every processed row that
in their turn causes significant memory growth.
the fix is to avoid use of get_field().

That was a pure test issue -- filter implementation in Perl did not work
on some platform (the bug occurred on Windows Server 2008 with
Cygwin Perl 5.10.0).