Reverting the previous patch

            
Range scan in descending order for c <= <col> <= c type of
ranges was ignoring the DESC flag.
However some engines like InnoDB have the primary key parts 
as a suffix for every secondary key.
When such primary key suffix is used for ordering ignoring 
the DESC is not valid.
But we generally would like to do this because it's faster.
      
Fixed by performing only reverse scan if the primary key is used.
Removed some dead code in the process.

mysql-test/r/innodb_mysql.result:
  Bug#37830 : test case
mysql-test/t/innodb_mysql.test:
  Bug#37830 : test case
sql/opt_range.cc:
  Bug#37830 : 
   - preserve and use used_key_parts to
     distinguish when a primary key suffix is used
   - removed some dead code
sql/opt_range.h:
  Bug#37830 : 
    - preserve used_key_parts
    - dead code removed
sql/sql_select.cc:
  Bug#37830 : Do only reverse order traversal
      if the primary key suffix is used.

- In QUICK_INDEX_MERGE_SELECT::read_keys_and_merge: when we got table->sort from Unique,
  tell init_read_record() not to use rr_from_cache() because a) rowids are already sorted
  and b) it might be that the the data is used by filesort(), which will need record rowids
  (which rr_from_cache() cannot provide).
- Fully de-initialize the table->sort read in QUICK_INDEX_MERGE_SELECT::get_next(). This fixes BUG#35477.
(bk trigger: file as fix for BUG#35478).

sql/filesort.cc:
  BUG#35478: sort_union() returns bad data when sort_buffer_size is hit
  - make find_all_keys() use quick->get_next() instead of init_read_record(r)/r.read_record() calls
  - added dbug printout
sql/mysql_priv.h:
  BUG#35478: sort_union() returns bad data when sort_buffer_size is hit
  - Added parameter to init_read_record
sql/opt_range.cc:
  BUG#35478: sort_union() returns bad data when sort_buffer_size is hit
  - In QUICK_INDEX_MERGE_SELECT::read_keys_and_merge: when we got table->sort from Unique,
    tell init_read_record() not to use rr_from_cache() because a) rowids are already sorted
    and b) it might be that the the data is used by filesort(), which will need record rowids
    (which rr_from_cache() cannot provide).
  - Fully de-initialize the table->sort read in QUICK_INDEX_MERGE_SELECT::get_next().
sql/records.cc:
  BUG#35478: sort_union() returns bad data when sort_buffer_size is hit
  - Added disable_rr_cache parameter to init_read_record
  - Added comment
sql/sql_acl.cc:
  BUG#35478: sort_union() returns bad data when sort_buffer_size is hit
  - Added parameter to init_read_record
sql/sql_delete.cc:
  BUG#35478: sort_union() returns bad data when sort_buffer_size is hit
  - Added parameter to init_read_record
sql/sql_help.cc:
  BUG#35478: sort_union() returns bad data when sort_buffer_size is hit
  - Added parameter to init_read_record
sql/sql_select.cc:
  BUG#35478: sort_union() returns bad data when sort_buffer_size is hit
  - Added parameter to init_read_record
sql/sql_table.cc:
  BUG#35478: sort_union() returns bad data when sort_buffer_size is hit
  - Added parameter to init_read_record
sql/sql_udf.cc:
  BUG#35478: sort_union() returns bad data when sort_buffer_size is hit
  - Added parameter to init_read_record
sql/sql_update.cc:
  BUG#35478: sort_union() returns bad data when sort_buffer_size is hit
  - Added parameter to init_read_record

Note: item->null_value is not updated before a call to
item->store(), item->is_null() is not too (in common case).

build)

The crash was caused by freeing the internal parser stack during the parser
execution.
This occured only for complex stored procedures, after reallocating the parser
stack using my_yyoverflow(), with the following C call stack:
- MYSQLparse()
- any rule calling sp_head::restore_lex()
- lex_end()
- x_free(lex->yacc_yyss), xfree(lex->yacc_yyvs)

The root cause is the implementation of stored procedures, which breaks the
assumption from 4.1 that there is only one LEX structure per parser call.

The solution is to separate the LEX structure into:
- attributes that represent a statement (the current LEX structure),
- attributes that relate to the syntax parser itself (Yacc_state),
so that parsing multiple statements in stored programs can create multiple
LEX structures while not changing the unique Yacc_state.

Now, Yacc_state and the existing Lex_input_stream are aggregated into
Parser_state, a structure that represent the complete state of the (Lexical +
Syntax) parser.


mysql-test/r/parser_stack.result:
  Bug#35577 (CREATE PROCEDURE causes either crash or syntax error depending on
  build)
mysql-test/t/parser_stack.test:
  Bug#35577 (CREATE PROCEDURE causes either crash or syntax error depending on
  build)
sql/sp.cc:
  Bug#35577 (CREATE PROCEDURE causes either crash or syntax error depending on
  build)
sql/sp_head.cc:
  Bug#35577 (CREATE PROCEDURE causes either crash or syntax error depending on
  build)
sql/sql_class.cc:
  Bug#35577 (CREATE PROCEDURE causes either crash or syntax error depending on
  build)
sql/sql_class.h:
  Bug#35577 (CREATE PROCEDURE causes either crash or syntax error depending on
  build)
sql/sql_lex.cc:
  Bug#35577 (CREATE PROCEDURE causes either crash or syntax error depending on
  build)
sql/sql_lex.h:
  Bug#35577 (CREATE PROCEDURE causes either crash or syntax error depending on
  build)
sql/sql_parse.cc:
  Bug#35577 (CREATE PROCEDURE causes either crash or syntax error depending on
  build)
sql/sql_prepare.cc:
  Bug#35577 (CREATE PROCEDURE causes either crash or syntax error depending on
  build)
sql/sql_trigger.cc:
  Bug#35577 (CREATE PROCEDURE causes either crash or syntax error depending on
  build)
sql/sql_view.cc:
  Bug#35577 (CREATE PROCEDURE causes either crash or syntax error depending on
  build)
sql/sql_yacc.yy:
  Bug#35577 (CREATE PROCEDURE causes either crash or syntax error depending on
  build)

            and value-list

The server returns unexpected results if a right side of the 
NOT IN clause consists of NULL value and some constants of
the same type, for example:

  SELECT * FROM t WHERE NOT t.id IN (NULL, 1, 2) 
  
may return 3, 4, 5 etc if a table contains these values.


The Item_func_in::val_int method has been modified:
unnecessary resets of an Item_func_case::has_null field 
value has been moved outside of an argument comparison
loop. (Also unnecessary re-initialization of the null_value
field has been moved).


mysql-test/r/func_in.result:
  Added test case for bug #37761.
mysql-test/t/func_in.test:
  Added test case for bug #37761.
sql/item_cmpfunc.cc:
  Bug #37761: IN handles NULL differently for table-subquery 
              and value-list
  
  The Item_func_in::val_int method has been modified:
  unnecessary resets of an Item_func_case::has_null field 
  value has been moved outside of an argument comparison
  loop. (Also unnecessary re-initialization of the null_value
  field has been moved).

libmysqld/emb_qcache.cc:
  Fixed build warning on Windows:
  ported the fix from 6.0 in 5.1

offset for time part in UUIDs was 1/1000 of what it
should be. In other words, offset was off.

Also handle the case where we count into the future
when several UUIDs are generated in one "tick", and
then the next call is late enough for us to unwind
some but not all of those borrowed ticks.

Lastly, handle the case where we keep borrowing and
borrowing until the tick-counter overflows by also
changing into a new "numberspace" by creating a new
random suffix.

mysql-test/r/func_misc.result:
  Show that time-part of UUIDs is correct now.
mysql-test/t/func_misc.test:
  Show that time-part of UUIDs is correct now
  by replicating the C-code's resultin SQL.
  Results also decode to expect date-data on
  command-line (external validation).
  
  No test for unwinding of borrowed ticks as
  this a) is a race and b) depends on what timer
  we get.
sql/item_strfunc.cc:
  correct offset for date/time-part of UUID.
  also make sure that when we counted into
  the future earlier (several UUIDs generated
  in same tick), we only give back as many
  "borrowed" ticks as we can without duplicating
  past timestamps. If our tick-counter overflows
  before we can give back, or if the system-clock
  is set back (by user or Daylight Saving Time),
  we create a new random suffix to avoid
  collisions and clear the tick-counter.

offset for time part in UUIDs was 1/1000 of what it
should be. In other words, offset was off.

Also handle the case where we count into the future
when several UUIDs are generated in one "tick", and
then the next call is late enough for us to unwind
some but not all of those borrowed ticks.

Lastly, handle the case where we keep borrowing and
borrowing until the tick-counter overflows by also
changing into a new "numberspace" by creating a new
random suffix.


mysql-test/r/func_misc.result:
  Show that time-part of UUIDs is correct now.
mysql-test/t/func_misc.test:
  Show that time-part of UUIDs is correct now
  by replicating the C-code's resultin SQL.
  Results also decode to expect date-data on
  command-line (external validation).
  
  No test for unwinding of borrowed ticks as
  this a) is a race and b) depends on what timer
  we get.
sql/item_strfunc.cc:
  correct offset for date/time-part of UUID.
  also make sure that when we counted into
  the future earlier (several UUIDs generated
  in same tick), we only give back as many
  "borrowed" ticks as we can without duplicating
  past timestamps. If our tick-counter overflows
  before we can give back, or if the system-clock
  is set back (by user or Daylight Saving Time),
  we create a new random suffix to avoid
  collisions and clear the tick-counter.