Before this fix, the test thread_cache failed with spurious failures.

The test used:
-- disconnect X
-- connect Y

while assuming that connection Y would reuse connection X slot in the thread cache.

For this to happen, the disconnect X operation must be given enough time to complete,
otherwise connect Y can be executed in the server before X actually finishes.

This fix uses wait conditions to make the test execution more controlled,
and more reproductible.

Before this fix, the test myisam_file_io executed:
- (a) an update on setup_instrument to disable non myisam file io instruments
- (b) a truncate on events_waits_history_long
and later
- (c) a select on events_waits_history_long

Surprisingly, events that were supposed to be disabled in (a) and removed in (b)
still were found in (c).

This happened for events such as 
  wait/io/file/innodb/innodb_data_file fil0fil.c: sync  
because the sync was started before (a) and completed after (b),
and as a consequence was added in the performance schema history, as expected.

Presence of these records in the history made the test fail. 

This fix makes the test script more robust to account for extra spill waits records in (c).

Fixing the testcase to use the database name
as connected_db instead of 'test' database.

The problem was due to a misuse of GCC asm constraints used to
implement a atomic load. On x86_64, the load was implemented
as a cmpxchg which implicitly uses the eax register as a
source and destination operand, yet the dummy value used for
comparison wasn't being properly loaded into eax (and other
problems).

The core problem is that cmpxchg is unnecessary as a load
on x86_64 as there are other simpler instructions such
as xadd. Even though, such instructions are only used to
have a memory barrier as load and stores are atomic by
definition. Hence, the solution is to explicitly issue the
required CPU and compiler barriers.

integral type. Use intptr which is designed to hold pointer values
and pass it to off_t.

metadata"

Improved error handling such that queries against Information_Schema.Tables won't
fail if a federated table can't make a remote connection.

the DROP statement ..."
      
Problem: When using temporary tables and closing a session, an
implicit DROP TEMPORARY TABLE IF EXISTS is written to the binary
log (while cleaning up the context of the session THD - see:
sql_class.cc:THD::cleanup which calls close_temporary_tables).
     
close_temporary_tables, first checks if the binary log is opened
and then proceeds to creating the DROP statements. Then, such
statements, are written to the binary log through
MYSQL_BIN_LOG::write(Log_event *). Inside, there is another check
if the binary log is opened and if not an error is returned. This
is where the faulty behavior is triggered. Given that the test
case replays a binary log, with temp tables statements, and right
after it issues RESET MASTER, there is a chance that is_open will
report false (when the mysql session is closed and the temporary
tables are written).
      
is_open may return false, because MYSQL_BIN_LOG::reset_logs is
not setting the correct flag (LOG_CLOSE_TO_BE_OPENED), on the
MYSQL_LOG_BIN::log_state (instead it sets just the
LOG_CLOSE_INDEX flag, leaving the log_state to
LOG_CLOSED). Thence, when writing the DROP statement as part of
the THD::cleanup, the thread could get a return value of false
for is_open - inside MYSQL_BIN_LOG::write, ultimately reporting
that it can't write the event to the binary log.
      
Fix: We fix this by adding the correct flag, missing in the
second close.

metadata"
            
Improved error handling such that queries against Information_Schema.Tables won't
fail if a federated table can't make a remote connection.

Improved error handling such that queries against Information_Schema.Tables won't
fail if a Federated table is unable to connect to remote host.

will not display "indicated result file not found" due to wrongly named
var directory.

It is not necessary to support INSERT DELAYED for a single value insert,
while we do not support that for multi-values insert when binlog is
enabled in SBR.

The lock_type is upgrade to TL_WRITE from TL_WRITE_DELAYED for
INSERT DELAYED for single value insert as multi-values insert
did when binlog is enabled. Then it's safe. And binlog it as
INSERT without DELAYED.

When using BINLOG statement to execute rows log events, session variables
foreign_key_checks and unique_checks are changed temporarily.  As each rows
log event has their own special session environment and its own
foreign_key_checks and unique_checks can be different from current session
which executing the BINLOG statement. But these variables are not restored
correctly after BINLOG statement. This problem will cause that the following
statements fail or generate unexpected data.

In this patch, code is added to backup and restore these two variables.
So BINLOG statement will not affect current session's variables again.

it needs curses.h to be included before term.h
on Solaris Express 11

The problem is that the logic which checks if a pointer is
valid relies on a poor heuristic based on the start and end
addresses of the data segment and heap.

Apart from miscalculating the heap bounds, this approach also
suffers from the fact that memory can come from places other
than the heap. See Bug#58528 for a more detailed explanation.

On Linux, the solution is to access the process's memory
through /proc/self/task/<tid>/mem, which allows for retrieving
the contents of pages within the virtual address space of
the calling process. If a address range is not mapped, a
input/output error is returned.

Problem: MySQL cp1251 did not support 'U+20AC EURO SIGN'
which was assigned a few years ago to 0x88.

Fix: adding mapping: 0x88 <-> U+20AC 

  @ mysql-test/include/ctype_8bit.inc
  New shared file to test 8bit character sets.

  @ mysql-test/r/ctype_cp1251.result
  @ mysql-test/t/ctype_cp1251.test
  Adding tests

  @ sql/share/charsets/cp1251.xml
  Adding mapping

  @ strings/ctype-extra.c
  Regenerating ctype-extra.c using strings/conf_to_src
  according to new cp1251.xml

After dropping and recreating the database specified along with --one-database
option at command line, mysql client keeps filtering the statements even after
the execution of a 'USE' command on the same database.

--one-database option enables the filtering of statements when the current
database is not the one specified at the command line. However, when the same
database is dropped and recreated the variable (current_db) that holds the
inital database name gets altered. This bug exploits the fact that current_db
initially gets set to null value (0) when a 'use db_name' follows the recreation
of same database db_name (speficied at the command line) and hence skip_updates
gets set to 1, which inturn triggers the further filtering of statements.

Fixed by making get_current_db() a no-op function when one_database is set,
and hence, under that condition current_db will not get altered.
Note, however the value of current_db can change when we execute 'connect'
command with a differnet database to reconnect to the server, in which case,
the behavior of --one-database will be formulated using this new database.