partitioning enhancement for Bug#14521864

engine

- Modify the way Item_cond::fix_fields() and Item_cond::eval_not_null_tables() 
  calculate bitmap for Item_cond_or::not_null_tables():
  if they see a "... OR inexpensive_const_false_item OR ..." then the item can
  be ignored.
- Updated test results. There can be more warnings produced since parts of WHERE 
  are evaluated more times.

MDEV-4815 - allow multiple  mysql_server_init() / mysql_server_end() in the same process, for embedded library.

- Reset  static variables that are used to signal "init done"  for DBUG, in dbug_end()
- Set string server variables to NULL after memory for the value is freed - avoids double free()
- fix DBUG_ASSERTs that happened during reinitialization.

- Let _ma_record_pos() set SEARCH_PART_KEY when doing a search on
  a prefix of a [unique] key.  Otherwise, _ma_search_pos() would 
  find the first key equal to search key, and assume it is also 
  the last one, which will make a wrong estimate of key's position.

  A wrong key position may cause min_pos > max_pos and records_in_range()
  will return 0, which will make the optimizer think it's an impossible 
  range while in fact it is not.

(fix of http://bugs.mysql.com/bug.php?id=69623)

  
In the case of loose scan used as input for order by, end_send()
didn't detect correctly that a loose scan was used, and didn't copy
the non-aggregated fields from the temp table used for ORDER BY.
  
The fix uses the fact that the quick select used for sorting is
attached to JOIN::pre_sort_join_tab instead of JOIN::join_tab.

MDEV-4782: Valgrind warnings (Conditional jump or move depends on uninitialised value) with InnoDB, semijoin
- in sub_select(): don't call table->file->position() when reading the first record
  produced an error.

Backport the fix olav.sandstaa@sun.com-20101102184747-qfuntqwj021imy9r:
"Fix for Bug#52660 Perf. regr. using ICP for MyISAM on range queries on an index containing TEXT" 
(together with further fixes in that code) into MyISAM and Aria.

mdev-4173: Wrong result (extra row) with semijoin=on, joins in outer query, LEFT JOIN in the subquery
Apply the patch from Patryk Pomykalski:
- create_internal_tmp_table_from_heap() will now return information whether
  the last row that we tried to write was a duplicate row.
(mysql-5.6 also has this change)

- Make JOIN::cleanup(true) also work correctly when the query is KILLed
  after join optimization was started but before a query plan was produced

MDEV-4536: ...sql/sql_base.cc:1598: bool close_thread_table(THD*, TABLE**): Assertion
- Make JOIN::cleanup(full=true) always free join optimization tabs.

- merge_same_index_scans() may put the same SEL_ARG tree in multiple result plans.
  make it call incr_refs() on the SEL_ARG trees that it does key_or() on, because 
  key_or(sel_arg_tree_1, sel_arg_tree_2) call may invalidate SEL_ARG trees pointed 
  by sel_arg_tree_1 and sel_arg_tree_2.
  

MDEV-4409 - Fix deadlock in MySQL key cache code, that can happen if there is a key cache resize running in parallel with an update.

If there is a key cache resize,a  thread writing to key cache, will pause waiting  until resize finishes. However this thread is won't be woken, because resize does not  signaling waiters anymore. This is a regression introduced in WL#86(segmented MyISAM key cache)
The fix is to unconditionally release  threads waiting on resize_queue when resize  finishes, as in pre-WL#86 code.

modified:
  mysql-test/suite/plugins/r/fulltext_plugin.result
  mysql-test/suite/plugins/t/fulltext_plugin.test
  plugin/fulltext/plugin_example.c
  sql/sql_show.cc
pending merges:
  Alexander Barkov 2013-07-09 [merge] Merge from 5.1
    Sergei Golubchik 2013-07-06 Bug #69682 - mysqld crashes after uninst...
    Sergei Golubchik 2013-05-24 MDEV-4575 MySQL client doesn't strip off...

modified:
  mysql-test/suite/plugins/r/fulltext_plugin.result
  mysql-test/suite/plugins/t/fulltext_plugin.test
  plugin/fulltext/plugin_example.c
  sql/sql_show.cc
pending merges:
  Sergei Golubchik 2013-07-06 Bug #69682 - mysqld crashes after uninstall ...
    Sergei Golubchik 2013-05-24 MDEV-4575 MySQL client doesn't strip off...

modified:
  include/my_time.h
  libmysql/libmysql.c
  mysql-test/r/adddate_454.result
  mysql-test/r/cast.result
  mysql-test/r/date_formats.result
  mysql-test/r/func_sapdb.result
  mysql-test/r/func_time.result
  mysql-test/r/mdev316.result
  mysql-test/r/parser.result
  mysql-test/r/partition_datatype.result
  mysql-test/r/partition_pruning.result
  mysql-test/r/type_date.result
  mysql-test/r/type_datetime.result
  mysql-test/suite/vcol/r/vcol_misc.result
  mysql-test/t/cast.test
  sql-common/my_time.c
  sql/field.cc
  sql/field_conv.cc
  sql/filesort.cc
  sql/item.cc
  sql/item.h
  sql/item_cmpfunc.cc
  sql/item_func.cc
  sql/item_strfunc.cc
  sql/item_timefunc.cc
  sql/sql_time.cc
pending merges:
  Sergei Golubchik 2013-07-03 MDEV-4667 DATE('string') incompability betwe...

MDEV-4643 MariaDB crashes consistently when trying a SELECT on VIEW with a UNION and an additional JOIN in SELECT

open derived temp tables *before* trying QUICK_SELECT for them,
handler::multi_range_read_info() needs an open table.

don't ignore the return value fix_fields()

MDEV-4257 Assertion `!table || (!table->read_set || bitmap_is_set(table->read_set, field_index))' fails on FROM subquery with fulltext search, derived_merge=on

remove emtpty Item_func_match::update_used_tables() method

Fix of nested join parsing of illegal query.

Cleanup: remove TIME_FUZZY_DATE.

Introduce TIME_FUZZY_DATES which means "very fuzzy, the resulting
value is only used for comparison. It can be invalid date, fine, as long as it can be
compared".

Updated many tests results (they're better now).

for field terminators, uchar was compared with char