I think I finally found the problem, managed to reproduce locally using a
sleep in the test case to simulate the particular race condition that causes
the test to fail often in Buildbot.

The test starts an ALTER TABLE that does repair by sort in one thread, then
another thread waits for the sort to be visible in SHOW PROCESSLIST and runs a
SHOW statement in parallel.

The problem happens when the sort manages to run to completion before the
other thread has the time to look at SHOW PROCESSLIST. In this case, the wait
times out because the state looked for has already passed.

Earlier I added some DEBUG_SYNC to prevent this race, but it turns out that
DEBUG_SYNC itself changes the state in the processlist. So when the debug sync
point was hit, the processlist was showing the wrong state, so the wait would
still time out.

Fixed now by looking for the processlist to contain either the "Repair by
sorting" state or the debug sync wait stage.

Also clean up previous attempts to fix it. Set the wait timeout back to
reasonable 60 seconds, and simplify the DEBUG_SYNC operations to work closer
to how the original test case was intended.

(Backport to 5.3)
(Attempt #2)
- Don't attempt to use BKA for materialized derived tables. The 
  table is neither filled nor fully opened yet, so attempt to 
  call handler->multi_range_read_info() causes crash.

(Backport to 5.3)
(variant #2, with fixed coding style)
- Make Mrr_ordered_index_reader::resume_read() restore index position 
  only if it was saved before with Mrr_ordered_index_reader::interrupt_read().

- TABLE::create_key_part_by_field() should not set PART_KEY_FLAG in field->flags
  = The reason is that it is used by hash join code which calls it to create a hash
    table lookup structure. It doesn't create a real index.
  = Another caller of the function is TABLE::add_tmp_key(). Made it to set the flag itself.

- The differences in join_cache.result could also be observed before this patch: one
  could put "FLUSH TABLES" before the queries and get exactly the same difference.

Increase timeout for check-testcase and friends, in an attempt to cure some random buildbot test failures.

Increase wait timeout in test main.myisam-metadata, in an attempt to get rid of Buildbot random failures.

1. Do not use NULL `info' field in processlist to select the thread of
interest. This can fail if the read of processlist ends up happening after
REAP succeeds, but before the `info' field is reset. Instead, select on the
CONNECTION_ID(), making sure we still scan the whole list to trigger the same
code as in the original test case.

2. Wait for the query to really complete before reading it in the
processlist. When REAP returns, it only means that ack has been sent to
client, the reset of query stage happens a bit later in the code.

Add missing REAP to the test.

A later test failed with strange incorrect values for COM_SELECT
in information_schema.global_status. Since global_status is updated
at the end of session activity, it seems appropriate to ensure that
all background connections have completed before accessing it.

(I checked that the original bug still triggers the test case after
the modification with REAP).

When UNIV_INTERN is missing in built-in XtraDB, this causes the
innodb_plugin to call the XtraDB version of the function instead
of its own (seen in --embedded-server test failure in Buildbot).
This in turn causes bad things to happen in case of difference
between XtranDB and innodb_plugin.

innodb_buffer_pool_pages_total depends on page size. On Power8 it is 65k
compared to 4k on Intel. As we round allocations on page size we may get
slightly more memory for buffer pool.

After constant row substitution the WHERE condition may be simplified and its multiple equality
may be changed. In this case the references to these multiple equalities from the COND_EQUAL
objects associated with ON expressions must be updated.
Also we have to take into account that this simplification may lead to equalities of the form
field=const that are mutually exclusive with some of the equalities in ON expressions. 

MDEV-6484: Assertion `tab->ref.use_count' failed on query with joins, constant table, multi-part key

- test_if_skip_sort_order()/create_ref_for_key() may change table 
  access from EQ_REF(index1) to REF(index2). 
- Doing so doesn't make much sense from optimization POV, but since 
  they are doing it, they should update tab->read_record.unlock_row
  accordingly.

revno: 4301
committer: Alexey Botchkov <holyfoot@askmonty.org>
branch nick: 10exp
timestamp: Tue 2014-07-22 15:28:15 +0500
message:
  gis-precise.test fixed to work on Power8.
------------------------------------------------------------
revno: 4295
committer: Alexey Botchkov <holyfoot@askmonty.org>
branch nick: 10exp
timestamp: Mon 2014-07-21 13:07:48 +0500
message:
  gis-precise test fixed to pass on Power8.

The data base lenth passed to invalidator fixed

* skip debian 44_scripts__mysql_config__libs.dpatch it does not apply anymore
  (and anyway it would not work for a static library)
* fix the path for install(mariadb.pc)

MDEV-5553 A view or procedure with a non existing definer can block "SHOW TABLE STATUS" with an unclear error message

Don't double-check privileges for a column in the GROUP BY that refers to
the same column in SELECT clause. Privileges were already checked for SELECT clause.

skip NULL VARCHAR key parts like it's done elsewhere

backport the new fix from 10.0

1. move cflags/libs cleanup from mysql_config.sh (runtime)
   to for_client.cmake (build time). Include/library paths are
   still calculated at runtime (they depend on the location of mysql_config)

2. Use cleaned-up cflags/libs to generate mariadb.pc

3. remove obsolete @expansions@ from mysql_config (for variables that are
   never set in cmake files)

add bsdutils dependency, because mariadb-server-5.5 deb package uses logger