LOAD DATA into partitioned MyISAM table

Problem was that both partitioning and myisam
used the same table_share->mutex for different protections
(auto inc and repair).

Solved by adding a specific mutex for the partitioning
auto_increment.

Also adding destroying the ha_data structure in
free_table_share (which is to be propagated
into 5.5).

This is a 5.1 ONLY patch, already fixed in 5.5+.

           REBUILD PARTITION under LOCK TABLE

Collapsed patch including updates from the reviews.

In case of failure in ALTER ... PARTITION under LOCK TABLE
the server could crash, due to it had modified the locked
table object, which was not reverted in case of failure,
resulting in a bad table definition used after the failed
command.

Solved by instead of altering the locked table object and
its partition_info struct, creating an internal temporary
intermediate table object used for altering,
just like the non partitioned mysql_alter_table.
So if an error occur before the alter operation is complete,
the original table is not modified at all.
But if the alter operation have succeeded so far that it
must be completed as whole,
the table is properly closed and reopened.
(The completion on failure is done by the ddl_log.)

mysql-test/suite/parts/inc/partition_fail.inc:
  Added tests under LOCK TABLE
mysql-test/suite/parts/r/partition_debug_innodb.result:
  Updated results
mysql-test/suite/parts/r/partition_debug_myisam.result:
  Updated results
mysql-test/suite/parts/r/partition_special_innodb.result:
  updated result
mysql-test/suite/parts/t/partition_special_innodb.test:
  changing comment, since this patch also fixes this.
sql/sql_partition.cc:
  Added TODO, to use DBUG_SUICIDE() instead of abort()
  to avoid core-files on expected crashes.
  Removed unused arguments to fast_end_partition.
  Opening a intermediate table in prep_alter_part_table, instead of altering
  (a possible locked) normally opened table.
  That way we do not have to do anything more than close
  the intermediate table on error,
  leaving the ordinary table opened and locked.
  Also making sure that the intermediate table are
  closed/destroyed on failure. If no error occur
  it is later destroyed in the end of fast_alter_partition_table.
  Added ha_external_lock to make sure MyISAM flushed the index file
  after copying the partitions.
  This also leads to removal of the special close and removal from
  the table cache for other instances of the table.
sql/sql_partition.h:
  Changed the arguments for prep_alter_part_table and
  fast_alter_partition_table to use an intermediate table
  instead of altering a (possibly locked) normal table.
sql/sql_table.cc:
  Using an intermediate table created in prep_alter_part_table
  to be used in fast_alter_partition_table, also closing/destroying
  it on failure.

Bug#57113: ha_partition::extra(ha_extra_function):
            Assertion `m_extra_cache' failed

Fix for bug#55458 included DBUG_ASSERTS causing
debug builds of the server to crash on
another multi-table update.

Removed the asserts since they where wrong.
(updated after testing the patch in 5.5).

mysql-test/r/partition.result:
  updated result
mysql-test/t/partition.test:
  Added test for bug#57113
sql/ha_partition.cc:
  Removed the assert for m_extra_cache when
  ::extra(HA_PREPARE_FOR_UPDATE) was called.

inline perl in the test.

in the MDL deadlock detector".

It is no longer needed as a better fix for this bug has
been pushed.

detector" that doesn't introduce bug #56715 "Concurrent
transactions + FLUSH result in sporadical unwarranted
deadlock errors".

Deadlock could have occurred when workload containing a mix
of DML, DDL and FLUSH TABLES statements affecting the same
set of tables was executed in a heavily concurrent environment.

This deadlock occurred when several connections tried to
perform deadlock detection in the metadata locking subsystem.
The first connection started traversing wait-for graph,
encountered a sub-graph representing a wait for flush, acquired
LOCK_open and dived into sub-graph inspection. Then it
encountered sub-graph corresponding to wait for metadata lock
and blocked while trying to acquire a rd-lock on
MDL_lock::m_rwlock, since some,other thread had a wr-lock on it.
When this wr-lock was released it could have happened (if there
was another pending wr-lock against this rwlock) that the rd-lock
from the first connection was left unsatisfied but at the same
time the new rd-lock request from the second connection sneaked
in and was satisfied (for this to be possible the second
rd-request should come exactly after the wr-lock is released but
before pending the wr-lock manages to grab rwlock, which is
possible both on Linux and in our own rwlock implementation).
If this second connection continued traversing the wait-for graph
and encountered a sub-graph representing a wait for flush it tried
to acquire LOCK_open and thus the deadlock was created.

The previous patch tried to workaround this problem by not
allowing the deadlock detector to lock LOCK_open mutex if
some other thread doing deadlock detection already owns it
and current search depth is greater than 0. Instead deadlock
was reported. As a result it has introduced bug #56715.

This patch solves this problem in a different way.
It introduces a new rw_pr_lock_t implementation to be used
by MDL subsystem instead of one based on Linux rwlocks or
our own rwlock implementation. This new implementation
never allows situation in which an rwlock is rd-locked and
there is a blocked pending rd-lock. Thus the situation which
has caused this bug becomes impossible with this implementation.

Due to fact that this implementation is optimized for
wr-lock/unlock scenario which is most common in the MDL
subsystem it doesn't introduce noticeable performance
regressions in sysbench tests. Moreover it significantly
improves situation for POINT_SELECT test when many
connections are used.

No test case is provided as this bug is very hard to repeat
in MTR environment but is repeatable with the help of RQG
tests.
This patch also doesn't include a test for bug #56715
"Concurrent transactions + FLUSH result in sporadical
unwarranted deadlock errors" as it takes too much time to
be run as part of normal test-suite runs.

config.h.cmake:
  We no longer need to check for presence of
  pthread_rwlockattr_setkind_np as we no longer
  use Linux-specific implementation of rw_pr_lock_t
  which uses this function.
configure.cmake:
  We no longer need to check for presence of
  pthread_rwlockattr_setkind_np as we no longer
  use Linux-specific implementation of rw_pr_lock_t
  which uses this function.
configure.in:
  We no longer need to check for presence of
  pthread_rwlockattr_setkind_np as we no longer
  use Linux-specific implementation of rw_pr_lock_t
  which uses this function.
include/my_pthread.h:
  Introduced new implementation of rw_pr_lock_t.
  Since it never allows situation in which rwlock is rd-locked
  and there is a blocked pending rd-lock it is not affected by
  bug #56405 "Deadlock in the MDL deadlock detector".
  This implementation is also optimized for wr-lock/unlock
  scenario which is most common in MDL subsystem. So it doesn't
  introduce noticiable performance regressions in sysbench tests
  (compared to old Linux-specific implementation). Moreover it
  significantly improves situation for POINT_SELECT test when
  many connections are used.
  As part of this change removed try-lock part of API for
  this type of lock. It is not used in our code and it would
  be hard to implement correctly within constraints of new
  implementation.
  Finally, removed support of preferring readers from
  my_rw_lock_t implementation as the only user of this
  feature was old rw_pr_lock_t implementation.
include/mysql/psi/mysql_thread.h:
  Removed try-lock part of prlock API.
  It is not used in our code and it would be hard
  to implement correctly within constraints of new
  prlock implementation.
mysys/thr_rwlock.c:
  Introduced new implementation of rw_pr_lock_t.
  Since it never allows situation in which rwlock is rd-locked
  and there is a blocked pending rd-lock it is not affected by
  bug #56405 "Deadlock in the MDL deadlock detector".
  This implementation is also optimized for wr-lock/unlock
  scenario which is most common in MDL subsystem. So it doesn't
  introduce noticiable performance regressions in sysbench tests
  (compared to old Linux-specific implementation). Moreover it
  significantly improves situation for POINT_SELECT test when
  many connections are used.
  Also removed support of preferring readers from
  my_rw_lock_t implementation as the only user of this
  feature was old rw_pr_lock_t implementation.

with CMake 2.8.3 builtin macro

This patch moves the regression test from variables.test to
variables_debug.test as the debug system variable is not 
available on release builds.

This crash occured if the same debug trace file was closed twice,
leading to the same memory being free'd twice. This could occur
if the "debug" server system variable refered to the same trace
file in both global and session scope.

Example of an order of events that would lead to a crash:
1) Enable debug tracing to a trace file (global scope)
2) Enable debug tracing to the same trace file (session scope)
3) Reset debug settings (global scope)
4) Reset debug settings (session scope)

This caused a crash because the trace file was, by mistake, closed
in 3), leading to the same memory being free'd twice when the file
was closed again in 4).

Internally, the debug settings are stored in a stack, with session
settings (if any) on top and the global settings below. Each connection
has its own stack. When a set of settings is changed, it must be 
determined if its debug trace file is to be closed. Before, this was done
by only checking below on the settings stack. So if the global settings
were changed, an existing debug trace file reference in session settings
would be missed. This caused the file to be closed even if it was in use,
leading to a crash later when it was closed again.

This patch fixes the problem by preventing the trace file from being shared
between global and session settings. If session debug settings are set without
specifying a new trace file, stderr is used for output. This is a change
in behaviour and should be reflected in the documentation.

Test case added to variables.test.

per-file comments:
  mysql-test/t/log_tables_debug.test
        This test shouldn't be run at the embedded server.

Use UNINIT_VAR workaround instead of LINT_INIT. The former can
also be used to silence false-positives in non-debug builds as
it actually does not cause new code to be generated.

Use UNINIT_VAR workaround instead of LINT_INIT. The former is
also used in non-debug builds as it doesn't cause changes.

argument of inline_mysql_mutex_init in sql_base.cc.

When initializing LOCK_dd_owns_lock_open mutex pass
correct PSI key instead of NULL value.

mysql-test/suite/perfschema/r/dml_setup_instruments.result:
  Updated test results after adding P_S instrumentation
  for LOCK_dd_owns_lock_open.
sql/sql_base.cc:
  When initializing LOCK_dd_owns_lock_open mutex pass
  correct PSI key instead of NULL value.

Temporarily disable strict aliasing warnings in order to get
wider coverage for optimized builds. Once the violations are
fixed and false-positives silenced, this flag should be removed.

sql/sql_cache.cc:
  Added include of send_data_in_chunks() definiton when macros EMBEDDED_LIBRARY is on.

Update to previous patch according to reviewers comments.

Removing parts.partition_alter4_innodb from default.experimental
(Also closed bug#45299 as a duplicate of bug#56659 as a result of this.)
Adding run of tests requiring --big-test flag to default.weekly to keep the coverage.

mysql-test/collections/default.experimental:
  Removed partition_alter4_innodb since it now requires --big-test flag to run
  since it is very time consuming.
mysql-test/collections/default.weekly:
  Added run of test that require --big-test flag, to be run on weekly basis.

After the patch for Bug#54579, multi inserts done with INSERT DELAYED
are binlogged as normal INSERT. During processing of the statement,
a new query string without the DELAYED keyword is made. The problem
was that this new string was incorrectly made when the INSERT DELAYED
was part of a prepared statement - data was read outside the allocated
buffer.

The reason for this bug was that a pointer to the position of the
DELAYED keyword inside the query string was stored when parsing the
statement. This pointer was then later (at runtime) used (via pointer
subtraction) to find the number of characters to skip when making a
new query string without DELAYED. But when the statement was re-executed
as part of a prepared statement, the original pointer would be invalid
and the pointer subtraction would give a wrong/random result.

This patch fixes the problem by instead storing the offsets from the
beginning of the query string to the start and end of the DELAYED 
keyword. These values will not depend on the memory position
of the query string at runtime and therefore not give wrong results
when the statement is executed in a prepared statement.

This bug was a regression introduced by the patch for Bug#54579.

No test case added as this bug is already covered by the existing
binlog.binlog_unsafe test case when running with valgrind.