A few problems were found in the fix for bug 43668:
1) Comparison of the YEAR column with NULL always returned TRUE;
2) Comparison of the YEAR column with constants always returned
   unpredictable result;
3) Unnecessary conversion warnings when comparing a non-integer
   constant with a NULL value in the YEAR column;

The problems described above have been resolved with an
exception: zero (i.e. invalid) YEAR column value comparison
with 00 or 2000 still fail (it is not a regression and it was
not a regression), so MIN/MAX on YEAR column containing zero
value still fail.

      
This fix has been proposed by Sergey Petrunya and has been contributed
under SCA by sca@askmonty.org.
      
The cause for this valgrind error is that in the function
add_cond_and_fix() in sql_select.cc an Item_cond_and object is
created. This is marked as fixed but does not have a correct
table_map() attribute. Later, in make_join_select(), if
engine_condition_pushdown is in use, this table map is used and
results in the valgrind error.
      
The fix is to add a call to update_used_tables() in add_cond_and_fix()
so that the table map is updated correctly.
      
This patch is tested by multiple existing tests (e.g. the tests
innodb_mysql, innodb, fulltext, compress all produces this valgrind
warning/error without this fix).

There are three issues that caused rpl_killed_ddl fails sporadically
in pb2:

 1) thd->clear_error() was not called before create Query event
if operation is executed successfully.
 2) DATABASE d2 might do exist because the statement to CREATE or
ALTER it was killed
 3) because of bug 43353, kill the query that do DROP FUNCTION or
    DROP PROCEDURE can result in SP not found

This patch fixed all above issues by:
 1) Called thd->clear_error() if the operation succeeded.
 2) Add IF EXISTS to the DROP DATABASE d2 statement
 3) Temporarily disabled testing DROP FUNCTION/PROCEDURE IF EXISTS.

Disabled execution in valgrind to avoid false positive memory
leaks due to fault-injection tests (i.e. call to abort()).

Removed rpl_cross_version from experimental list.

{PROCEDURE|FUNCTION} FROM ...'

The master would hit an assertion when binary log was
active. This was due to the fact that the thread's diagnostics
area was being cleared before writing to the binlog,
independently of mysql_routine_grant returning an error or
not. When mysql_routine_grant was to return an error, the return
value and the diagnostics area contents would
mismatch. Consequently, neither my_ok would be called nor an
error would be signaled in the diagnostics area, eventually
triggering the assertion in net_end_statement.

We fix this by not clearing the diagnostics area at binlogging
time. 

solaris after a crash
      
This patch adds a Solaris-specific version of
print_stacktrace() which uses printstack(2), available on all
Solaris versions since Solaris 9. (While Solaris 11 adds
support for the glibc functions backtrace_*() as of
PSARC/2007/162, printstack() is used for consistency over all
Solaris versions.)

The symbol names are mangled, so use of c++filt may be
required as described in the MySQL documentation.

field='const1' AND field='const2' in some cases

Building multiple equality predicates containing
a constant which is compared as a datetime (with a field)
we should take this fact into account and compare the 
constant with another possible constatns as datetimes 
as well.

E.g. for the
SELECT ... WHERE a='2001-01-01' AND a='2001-01-01 00:00:00'
we should compare '2001-01-01' with '2001-01-01 00:00:00' as
datetimes but not as strings.

The problem was that the multiple evaluations of a ENCODE or
DECODE function within a single statement caused the random
generator to be reinitialized at each evaluation, even though
the parameters were constants.

The solution is to initialize the random generator only once
if the password (seed) parameter is constant.

This patch borrows code and ideas from Georgi Kodinov's patch.

Post-merge fix: Redirect stderr to a file as to avoid buffering
problems due to redirecting stderr to stdout.

This patch fixes three bugs as follows. First, aborting the server while purging
binary logs might generate orphan files due to how the purge operation was
implemented:

          (purge routine - sql/log.cc - MYSQL_BIN_LOG::purge_logs)

      1 - register the files to be removed in a temporary buffer.
      2 - update the log-bin.index.
      3 - flush the log-bin.index.
      4 - erase the files whose names where register in the temporary buffer
      in step 1.

Thus a failure while  executing step 4 would generate an orphan file. Second,
a similar issue might happen while creating a new binary as follows:

          (create routine - sql/log.cc - MYSQL_BIN_LOG::open)

      1 - open the new log-bin.
      2 - update the log-bin.index.

Thus a failure while executing step 1 would generate an orphan file.

To fix these issues, we record the files to be purged or created before really
removing or adding them. So if a failure happens such records can be used to
automatically remove dangling files. The new steps might be outlined as follows:

          (purge routine - sql/log.cc - MYSQL_BIN_LOG::purge_logs)

      1 - register the files to be removed in the log-bin.~rec~ placed in
      the data directory.
      2 - update the log-bin.index.
      3 - flush the log-bin.index.
      4 - delete the log-bin.~rec~.

          (create routine - sql/log.cc - MYSQL_BIN_LOG::open)

      1 - register the file to be created in the log-bin.~rec~
      placed in the data directory.
      2 - open the new log-bin.
      3 - update the log-bin.index.
      4 - delete the log-bin.~rec~.

          (recovery routine - sql/log.cc - MYSQL_BIN_LOG::open_index_file)

      1 - open the log-bin.index.
      2 - open the log-bin.~rec~.
      3 - for each file in log-bin.~rec~.
        3.1 Check if the file is in the log-bin.index and if so ignore it.
        3.2 Otherwise, delete it.

The third issue can be described as follows. The purge operation was allowing
to remove a file in use thus leading to the loss of data and possible
inconsistencies between the master and slave. Roughly, the routine was only
taking into account the dump threads and so if a slave was not connect the
file might be delete even though it was in use.

After-push minor code cleanup for WL 2360: unnecessary external
reference to LOCK_thread_count has been removed from ha_innodb.cc.

"mysql_upgrade (ver 5.1) add 3 fields to mysql.proc table but does
not set values".
            
mysql_upgrade (ver 5.1) adds 3 fields (character_set_client, 
collation_connection and db_collation) to the mysql.proc table, but 
does not set any values. When we run stored procedures, which were 
created with mysql 5.0, a warning is logged into the error log.
            
The solution to this is for mysql_upgrade to set default best guess
values for these fields. A warning is also written during upgrade, to
make the user aware that default values are set.

Test case cleanup.

When checking for an error after removing the special view error handler the code
was not taking into account that open_tables() may fail because of the current
statement being killed. 
Added a check for thd->killed.
Added a client program to test it.

Problem: Item_char_typecast reported wrong max_length when
casting to BINARY, which lead, in particular, in wrong
"ORDER BY BINARY(char_column)" results.

Fix: making Item_char_typecast report correct max_length.

  @ mysql-test/r/ctype_utf16.result
    Fixing old incorrect test result.
  @ mysql-test/r/ctype_utf32.result
    Fixing old incorrect test result.
  @ mysql-test/r/ctype_utf8.result
    Adding new test
  @ mysql-test/t/ctype_utf8.test
    Adding new test
  @ sql/item_timefunc.cc
    Making Item_char_typecast report correct max_length
    when cast is done to BINARY.

Problem: SHOW CREATE FUNCTION and SELECT DTD_IDENTIFIER FROM I_S.ROUTINES
returned wrong values in case of ENUM return data type and UCS2
character set.

Fix: the string to collect returned data type was incorrectly set to
"binary" character set, therefore UCS2 values where returned with
extra '\0' characters.
Setting string character set to creation_ctx->get_client_cs()
in sp_find_routine(), and to system_charset_info in sp_create_routine
fixes the problem.

Adding tests:
- the original test with Latin letters
- an extra test with non-Latin letters

Actually there is two different bugs.
The first one caused crash on queries with WHERE condition over views
containing WHERE condition. A wrong check for prepared statement phase led
to items for view fields being allocated in the execution memory and freed
at the end of execution. Thus the optimized WHERE condition refers to
unallocated memory on the second execution and server crashed.
The second one caused by the Item_cond::compile function not saving changes
it made to the item tree. Thus on the next execution changes weren't
reverted and server crashed on dereferencing of unallocated space.

The new helper function called is_stmt_prepare_or_first_stmt_execute
is added to the Query_arena class.
The find_field_in_view function now uses
is_stmt_prepare_or_first_stmt_execute() to check whether
newly created view items should be freed at the end of the query execution.
The Item_cond::compile function now saves changes it makes to item tree.

the last IF ELSE part which decides the plugin name is not relevant as we still have
to substitute the occurences of INNOBASE with INNODB_PLUGIN.
Remove the last IF ELSE part in CMakeLists.txt as it doesn't make sense in 5.1.

manual merge 5.0-->5.1, updating InnoDB plugin.

The bug 38816 changed the lock that protects THD::query from
LOCK_thread_count to LOCK_thd_data, but didn't update the associated
InnoDB functions.

1. The innobase_mysql_prepare_print_arbitrary_thd and the
innobase_mysql_end_print_arbitrary_thd InnoDB functions have been
removed, since now we have a per-thread mutex: now we don't need to wrap
several inter-thread access tries to THD::query with a single global
LOCK_thread_count lock, so we can simplify the code.

2. The innobase_mysql_print_thd function has been modified to lock
LOCK_thd_data in direct way.