When in function remove_eq_conds() a sub-formula of the processed condition
is replaced for another formula we should ensure that in the resulting
formula AND/OR levels must alternate.

The patch to fix mdev-4418 turned out to be incorrect.
At the substitution of single row tables in make_join_statistics()
the used multiple equalities may change and references to the new multiple
equalities must be updated. The function remove_eq_conds() takes care of it and
it should be called right after the substitution of single row tables.
Calling it after the call of make_join_statistics was a mistake.

Made sure that degenerate conjunctions/disjunctions are obtained from
AND/OR conditions.

MDEV-4908: Assertion `((Item_cond *) cond)->functype() == ((Item_cond *) new_item)->functype()' fails on a query with IN and equal conditions, AND/OR, materialization+semijoin

A new AND Item should be prepared (fix_field() call) before using.

had been merged into 5.5.

Corrected the result of the output from the test case for mdev 4895.

Fix bug MDEV-4895 Valgrind warnings (Conditional jump or move depends on uninitialised value) in Field_datetime::get_date on GREATEST(..) IS NULL

Analysis:
The cause of the valgrind warning was an attempt to evaluate a Field that was not yet read.
The reason was that on one hand Item_func_isnotnull was marked as constant by
Item_func_isnotnull::update_used_tables, and this allowed eval_const_cond() to be called.
On the other hand Item_func_isnotnull::val_int() evaluated its argument as if it was not
constant.

Solution:
The fix make sure that Item_func_isnotnull::val_int() doesn't evaluate its argument when
it is constant and cannot be NULL, because the result is known in this case. 

had been discovered when merging the patch from 5.3 into 5.5.

After single row substitutions there might appear new equalities.
They should be properly propagated to all AND/OR levels the WHERE
condition. It's done now with an additional call of remove_eq_conds(). 

This patch almost totally revised the patch for bug mdev-4177.
The latter had too many defects. In particular, it did not
propagate multiple equalities formed when merging a degenerate
disjunct into underlying AND formula.

This a an old legacy performance bug.
When a very selective range scan existed for the second table in a join,
and, at the same time, there was another range condition depending on the
fields of the first table, the optimizer chose a plan with
'Range checked for each record'. This plan was extremely inefficient in
comparison with the regular selective range scan.
As a matter of fact the range scan chosen for each record was the same as
that selective range scan. 

Changed the test case for bug 24776 to preserve the old output for explain.
 

MDEV-4812 Valgrind warnings (Invalid write) in dynamic_column_update_many on COLUMN_ADD

Fixed problem of working on wrong data (do not allow offset to out of string length).

Fixing a typo:  bit AND (&) was erroneously used instead of logical AND (&&) 

MDEV-4823: Server crashes in Item_func_not::fix_fields on creating a table with a virtual column using NOT

fix_field() call protocol was brocken (zero pointer passed as link to item which is possible only if you are sure that there can not be Items which transforms).

   not_enough_points() introduced to check if the spatial object is incorrect.

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...

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

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).

modified:
  sql/time.cc

Item_func_min_max::get_date() did not check the
returned value against the fuzzy_date flags, so
it could return a bad value to the caller that
expects a good date (e.h. CONVERT_TZ).


modified:
  mysql-test/r/type_date.result
  mysql-test/r/type_datetime.result
  mysql-test/r/type_time.result
  mysql-test/t/type_date.test
  mysql-test/t/type_datetime.test
  mysql-test/t/type_time.test
  sql/item_func.cc
  sql/item_timefunc.cc
  sql/mysql_priv.h
  sql/time.cc

modified:
  mysql-test/r/func_time.result
  mysql-test/t/func_time.test
  sql/item_timefunc.cc
  sql/mysql_priv.h

modified:
  mysql-test/r/ps_2myisam.result
  mysql-test/r/ps_3innodb.result
  mysql-test/r/ps_4heap.result
  mysql-test/r/ps_5merge.result
  mysql-test/r/type_datetime_hires.result
  mysql-test/suite/maria/r/ps_maria.result
  mysql-test/t/type_datetime_hires.test
  sql/item_timefunc.h

mysql_derived_merge_for_insert() should not be called for views or derived tables which are not put (directly or via other views) in main SELECT_LEX "join list".

extend 5.1 client library to read 4 byte capabilities from the first handshake packet.
two higher bytes are always zeros for 5.1 servers.