Merge 5.3 into 5.3-mwl89.

Merge MWL#89 with 5.3.

- Make equality-substitution-for-ref-access code in JOIN::optimize() treat join_tab->ref.key_copy correctly
  (in the way create_ref_for_key() has filled it).

The bug in the function print_keyuse() caused crashes if
hash join could be used. It happened because the function
ignored the fact that KEYUSE structures could be created
for hash joins as well. 

sql/mysqld.cc:
  Fixed: optimize_join_buffer_size was missing in the description of possible
  options for the optimizer switch.
sql/sql_select.cc:
  Fixed: initialization for the field ref_table_rows of the KEYUSE structure was 
  missing (as a result of a lame merge).

- Make get_constant_key_infix() take into account that there may be SEL_TREEs with
  type=SEL_ARG::MAYBE_KEY, which it cannot process, because they are not real ranges
  but rather indications that we might have been able to construct a range if we had
  values for some other tables' fields. 
  (check_quick_select() already has such check)

client/readline.cc:
  Initialize not used variable (to kill wrong compiler warning)
mysql-test/suite/handler/aria.result:
  Updated test result
mysql-test/suite/handler/handler.inc:
  Changed index to ensure rows are in a fixed order
mysql-test/suite/handler/heap.result:
  Updated test result
mysql-test/suite/handler/innodb.result:
  Updated test result
mysql-test/suite/handler/myisam.result:
  Updated test result
plugin/handler_socket/handlersocket/Makefile.am:
  Use CXX flags to compile
sql/filesort.cc:
  Initialize variable that may be used
sql/log.cc:
  Initialize not used variable (to kill wrong compiler warning)
sql/opt_range_mrr.cc:
  Fixed cast to avoid compiler warning
storage/xtradb/fil/fil0fil.c:
  Added cast to avoid compiler warning

- Don't access THD::killed directly from ha_innodb.cc. This is forbidden because 
  THD has different membership (and so, different member offsets) in regular and embedded server.
  Access must be done through thd_killed() function.

- if we're interrupted by the user while in XtraDB, return the proper code.

even in the cases when there existed range/index-merge scans that
were cheaper than the full table scan.
This was a defect/bug of the implementation of mwl #128. 
Now hash join can work not only with full table scan of the joined
table, but also with full index scan, range and index-merge scans.
Accordingly, in the cases when hash join is used the column 'type'
in the EXPLAINs can contain now 'hash_ALL', 'hash_index', 'hash_range'
and 'hash_index_merge'. If hash join is coupled with a range/index_merge
scan then the columns 'key' and 'key_len' contain info not only on
the used hash index, but also on the indexes used for the scan.   

- Linking now with g++ instead of gcc with 'compile-dist' to solve problems with handlersocket/client
- Fixed bug in heap tables when doing handler read next-prev over last row


BUILD/compile-dist:
  - Linking now with g++ instead of gcc with 'compile-dist' to solve problems with handlersocket/client
cmd-line-utils/libedit/vi.c:
  Fixed compiler warning about not checking return value for write
mysql-test/r/index_intersect.result:
  Updated results (missed this file in my last push)
mysql-test/suite/handler/aria.result:
  Updated test results
mysql-test/suite/handler/handler.inc:
  Changed test to use read next/read prev on key where there are duplicates that can come in different order depending on system
  Added testing of read next-prev over last row and read prev-next around first row
mysql-test/suite/handler/heap.result:
  Updated test results
mysql-test/suite/handler/init.inc:
  More rows to test
mysql-test/suite/handler/innodb.result:
  Updated test results
mysql-test/suite/handler/interface.result:
  Updated test results
mysql-test/suite/handler/myisam.result:
  Updated test results
mysql-test/t/variables-big.test:
  Fixed test to not fail on windows
mysql-test/valgrind.supp:
  Removed not matching fun: to get rid of valgrind warning
storage/heap/hp_rfirst.c:
  Added state so that we know if we have an active position in the index.
storage/heap/hp_rkey.c:
  Added state so that we know if we have an active position in the index.
storage/heap/hp_rnext.c:
  Handle reading several next after finding the last row (this caused a crash before)
storage/heap/hp_rprev.c:
  Handle reading several prev after finding the first row (this caused a crash before)
storage/xtradb/buf/buf0buf.c:
  Fixed compiler warning about uninitialized value

dbug/dbug.c:
  Fixed compiler warnings on windows
mysql-test/r/index_intersect_innodb.result:
  Don't print number of rows as this varies
mysql-test/suite/funcs_1/r/processlist_val_no_prot.result:
  Update to use new State
mysql-test/suite/handler/heap.result:
  Update results
mysql-test/suite/handler/heap.test:
  Changed key used in test as the key 'b' will not guarantee order of the two last elements (as the key value is the same)
mysql-test/suite/pbxt/r/lock_multi.result:
  Update to use new State
mysql-test/t/index_intersect.test:
  Don't print number of rows as this varies
mysql-test/valgrind.supp:
  Added suppression for linux
mysys/hash.c:
  Fixed compiler warnings on windows
plugin/handler_socket/handlersocket/database.cpp:
  Fixed compiler warnings
sql-common/client_plugin.c:
  Changed variable to define to avoid compiler warnings when variable is not used
sql-common/my_time.c:
  Initialize all my_time elements to avoid compiler warnings
storage/oqgraph/ha_oqgraph.cc:
  Use right function (to avoid compiler warning)
storage/pbxt/src/table_xt.cc:
  Initialize variables (to avoid compiler warnings)

Split the tests for MWL#89 into two parts - one for bugs
(currently active), and one for functionality tets
(currently in progress, and thus disabled).

Disable the test for LP BUG#718593.

where bison runs in parallel with the same input and output files

- Cherrypick MBUG#688404  (PBXT crashes in debug/x64)
- Fix unixism (rm -rf) in the test suite_timeout
- Avoid plugin tests on Windows/embedded, plugins do not and will not work here

- Fixed compiler errors
- Modified Makefiles to be part of plugin directory
- Some minor changes in database.cpp to use the new MariaDB handler interface

Fix is to move extern "C" at the start of header file.

sql/multi_range_read.cc:
  Added printing of error if something goes wrong in get_next()
  (Not critical for this bug fix, but this was something that I noticed while testing and found missing)
storage/myisam/mi_rkey.c:
  Fixed wrong error number in mi_yield_and_check_if_killed()

Fix for lp:711565 "Index Condition Pushdown can make a thread hold MyISAM locks as well as be unKILLable for long time"
- In Maria/MyISAM: Release/re-acquire locks to give queries that wait on them a chance to make progress
- In Maria/MyISAM: Change from numeric constants to ICP_RES values.
- In Maria: Do check index condition in maria_rprev() (was lost in the merge/backport?)
- In Maria/MyISAM/XtraDB: Check if the query was killed, and return immediately if it was.

Added new storage engine error: HA_ERR_ABORTED_BY_USER, for handler to signal that it detected a kill of the query and aborted

Authors: Sergey Petrunia & Monty

include/my_base.h:
  Added HA_ERR_ABORTED_BY_USER, for handler to signal that it detected a kill of the query and aborted
include/my_handler.h:
  Added comment
mysql-test/r/myisam_icp.result:
  Updated test
mysql-test/t/myisam_icp.test:
  Drop used tables at start of test
  Added test case that can help with manual testing of killing index condition pushdown query.
mysys/my_handler_errors.h:
  Text for new storage engine error
sql/handler.cc:
  If engine got HA_ERR_ABORTED_BY_USER, send kill message.
sql/multi_range_read.cc:
  Return error code
storage/maria/ha_maria.cc:
  Added ma_killed_in_mariadb() to detect kill.
  Ensure that file->external_ref points to TABLE object.
storage/maria/ma_extra.c:
  Dummy test-if-killed for standalone
storage/maria/ma_key.c:
  If ma_check_index_cond() fails, set my_errno and info->cur_row.lastpos
storage/maria/ma_rkey.c:
  Release/re-acquire locks to give queries that wait on them a chance to make progress
  Check if the query was killed, and return immediately if it was
storage/maria/ma_rnext.c:
  Check if the query was killed, and return immediately if it was
  Added missing fast_ma_writeinfo(info)
storage/maria/ma_rnext_same.c:
  Check if the query was killed, and return immediately if it was
  Added missing fast_ma_writeinfo(info)
storage/maria/ma_rprev.c:
  Check if the query was killed, and return immediately if it was
  Added missing fast_ma_writeinfo(info) and ma_check_index_cond()
storage/maria/ma_search.c:
  Give error message if we find a wrong key
storage/maria/ma_static.c:
  Added pointer to test-if-killed function
storage/maria/maria_def.h:
  New prototypes
storage/myisam/ha_myisam.cc:
  Added mi_killed_in_mariadb()
  Ensure that file->external_ref points to TABLE object.
storage/myisam/mi_extra.c:
  Dummy test-if-killed for standalone
storage/myisam/mi_key.c:
  If ma_check_index_cond() fails, set my_errno and info->lastpos
storage/myisam/mi_rkey.c:
  Ensure that info->lastpos= HA_OFFSET_ERROR in case of error
  Release/re-acquire locks to give queries that wait on them a chance to make progress
  Check if the query was killed, and return immediately if it was
  Reorder code to do less things in case of error.
  Added missing fast_mi_writeinfo()
storage/myisam/mi_rnext.c:
  Check if the query was killed, and return immediately if it was
  Simplify old ICP code
  Added missing fast_ma_writeinfo(info)
storage/myisam/mi_rnext_same.c:
  Check if the query was killed, and return immediately if it was
  Added missing fast_mi_writeinfo(info)
storage/myisam/mi_rprev.c:
  Check if the query was killed, and return immediately if it was
  Simplify error handling of ICP
  Added missing fast_mi_writeinfo(info)
storage/myisam/mi_search.c:
  Give error message if we find a wrong key
storage/myisam/mi_static.c:
  Added pointer to test-if-killed function
storage/myisam/myisamdef.h:
  New prototypes
storage/xtradb/handler/ha_innodb.cc:
  Added DB_SEARCH_ABORTED_BY_USER and ha_innobase::is_thd_killed()
  Check if the query was killed, and return immediately if it was
storage/xtradb/handler/ha_innodb.h:
  Added prototype
storage/xtradb/include/db0err.h:
  Added DB_SEARCH_ABORTED_BY_USER
storage/xtradb/include/row0mysql.h:
  Added possible ICP errors
storage/xtradb/row/row0sel.c:
  Use ICP errors instead of constants.
  Detect if killed and return B_SEARCH_ABORTED_BY_USER

The patch also adjusts several instable test results
to order the result.

Analysis:

The function prev_record_reads() may skip (jump over)
some query plan nodes where record_count < 1. At the
same time, even though get_partial_join_cost() uses
all first N plan nodes after the last constant table,
it may produce a smaller record_count than
prev_record_reads(), because the record count for
some plan nodes may be < 1, and these nodes may not
participate in prev_record_reads.

Solution:
The current solution is to treat the result of
get_partial_join_cost() as the upper bound for the
total number of unique lookup keys.

This bug extends the fix for LP BUG#715027 to cover one
more case of an Item being transformed, and its property
Item::with_subselect not being updated because
quick_fix_fields doesn't recalculate any properties.

Adjusted test results.

Adjusted test results of EXPLAIN EXTENDED where complex
and conditions are flattened as a result of calling
fix_fields instead of quick_fix_field.

Analysis:
Before calling:
  write_record= (select->skip_record(thd) > 0);
the function find_all_keys needs to restore the original read/write
sets of the table that is sorted if the condition select->cond
contains a subquery.

This didn't happen in this test case because the flag "with_subselect"
was not set properly for select->cond.

The reason for the flag not being set properly, was that this condition
was rewritten by add_cond_and_fix() inside make_join_select() by:

      /* Add conditions added by add_not_null_conds(). */
      if (tab->select_cond)
        add_cond_and_fix(thd, &tmp, tab->select_cond);

However, the function add_cond_and_fix() called the shortcut method
Item::quick_fix_field() that didn't update the "with_subselect"
property.

Solution:
Call the complete Item::fix_fields() to update all Item properties,
including "with_subselect".

Huge static libraries like libmysqld might not build if /MACHINE flag is missing 
for librarian with the correct processor architecture.

Fix is to add /MACHINE flag  for x64 builds