Every subsequent query to a merge table with indexes was lowering
down cardinality.

The problem was that key statistics was not cleared when merge
children were detached. Causing next attach children perform
incremental key statistics calculation.

Fixed by clearing key statistics when attaching first child.

Documented behaviour was broken by the patch for bug 33699
that actually is not a bug.

This fix reverts patch for bug 33699 and reverts the
UPDATE of NOT NULL field with NULL query to old
behavior.

            ORDER BY could cause a server crash

Dependent subqueries like

  SELECT COUNT(*) FROM t1, t2 WHERE t2.b
   IN (SELECT DISTINCT t2.b FROM t2 WHERE t2.b = t1.a)

caused a memory leak proportional to the
number of outer rows.


The make_simple_join() function has been modified to
JOIN class method to store join_tab_reexec and
table_reexec values in the parent join only
(make_simple_join of tmp_join may access these values
via 'this' pointer of the parent JOIN).

NOTE: this patch doesn't include standard test case (this is
"out of memory" bug). See bug #42037 page for test cases.

Problem: some queries using NAME_CONST(.. COLLATE ...)
lead to server crash due to failed type cast.

Fix: return the underlying item's type in case of
NAME_CONST(.. COLLATE ...) to avoid wrong casting.

   code backported from 6.0


per-file messages:
  include/my_global.h
    Remove SC_MAXWIDTH. This is unused and irrelevant nowadays.
  include/my_sys.h
    Remove errbuf declaration and unused definitions.
  mysys/my_error.c
    Remove errbuf definition and move and adjust ERRMSGSIZE.
  mysys/my_init.c
    Declare buffer on the stack and use my_snprintf.
  mysys/safemalloc.c
    Use size explicitly. It's more than enough for the message at hand.
  sql/sql_error.cc
    Use size explicitly. It's more than enough for the message at hand.
  sql/sql_parse.cc
    Declare buffer on the stack. Use my_snprintf as it will result in
    less stack space being used than by a system provided sprintf --
    this allows us to put the buffer on the stack without causing much
    trouble. Also, the use of errbuff here was not thread-safe as the
    function can be entered concurrently from multiple threads.
  sql/sql_table.cc
    Use MYSQL_ERRMSG_SIZE. Extra space is not needed as my_snprintf will
    nul terminate strings.
  storage/myisam/ha_myisam.cc
Use MYSQL_ERRMSG_SIZE.
  sql/share/errmsg.txt
    Error message truncation in test "innodb" in embedded mode
    filename in the error message can safely take up to 210 symbols.

Accessing well defined MERGE table may return an error
stating that the merge table is incorrectly defined. This
happens if MERGE child tables were accessed before and we
failed to open another incorrectly defined MERGE table in
this connection.

myrg_open() internally used my_errno as a variable for determining
failure, and thus could be tricked into a wrong decision by other
uses of my_errno.

With this fix we use function local boolean flag instead of my_errno
to determine failure.

Problem:
   RelativeLocationPath can appear only after a node-set expression
   in the third and the fourth branches of this rule:
     PathExpr :: =  LocationPath
                    | FilterExpr
                    | FilterExpr '/' RelativeLocationPath
                    | FilterExpr '//' RelativeLocationPath
   XPatch code didn't check the type of FilterExpr and crashed.
Fix:
   If FilterExpr is a scalar expression
   (variable reference, literal, number, scalar function call)
   return error.

fixing build issue, caused by the previous push.

            
The bug happened because filtering-out a STMT_END_F-flagged event so that
the transaction COMMIT finds traces of incomplete statement commit.
Such situation is only possible with ndb circular replication. The filtered-out
rows event is one that immediately preceeds the COMMIT query event.
      
Fixed with deploying an the rows-log-event statement commit at executing
of the transaction COMMIT event. 
Resources that were allocated by other than STMT_END_F-flagged event of
the last statement are clean up prior execution of the commit logics.

 - Properly set --bindir=$path_client_bindir and --basedir=$basedir by adding %s format specifier

           upgrading lock, even with low_priority_updates

The problem is that there is no mechanism to control whether a
delayed insert takes a high or low priority lock on a table.

The solution is to modify the delayed insert thread ("handler")
to take into account the global value of low_priority_updates
when taking table locks. The value of low_priority_updates is
retrieved when the insert delayed thread is created and will
remain the same for the duration of the thread.

+ fix wrong resultfile have_outfile.require

Option opt_threads is deprecated in 5.1, and a warning is
printed when used. Will remove in 6.0.

      
There was a type casting problem in the storage/innobase/handler/ha_innodb.cc,
(int ha_innobase::write_row(...)). Innobase uses has an internal error variable
of type 'ulint' while mysql uses an 'int'. 
      
To fix the problem the function manipulates an error variable of
type 'ulint' and only casts it into 'int' when needs to return the value.

The original symptoms of this bug have been fixed as a consequence of other bug fixes.
Taking this time to correct some formatting, such as replacing error numbers with names.
Beginning this with 5.0

The patch adds restart of mysql server and replacing of binlog file 
when mysql server is stopped.

   - If missing: add "disconnect <session>"
   - If physical disconnect of non "default" sessions is not finished
     at test end: add routine which waits till this happened
+ additional improvements like
  - remove superfluous files created by the test
  - replace error numbers by error names
  - remove trailing spaces, replace tabs by spaces
  - unify writing of bugs within comments
  - correct comments
  - minor changes of formatting
Modifications according to the code review are included.
Fixed tests:
grant2
grant3
lock_tables_lost_commit
mysqldump
openssl_1
outfile

There are two issues: 
      1. 6.0 uses the obsolate master-*** server options;
      2. the test is not deterministic in that although master vs slave consistency is
         fine, two runs of the test can have different results. The reason of the
         non-determinism is the combination of 
         a chosen way to demo results and the ndb_autoincrement_prefetch_sz feature.

The current patch fixes the 2nd issue by putting out results via diff_table macro
instead of the former run-sensitive method.
The 1st issue is going to be fixed by a separate patch to 6.0.

Problem:
Custom UCA collations didn't set the MY_CS_STRNXFRM flag,
which resulted in "prefix_search" method instead of
the required "seq_search".

Problem2: (not metioned in the bug report)
Custom UCA collations didn't also set the MY_CS_UNICODE flag,
so an attempt to compare a column with a custom UCA collation
to another column with a non-Unicode character set led to
the "illegal mix of collation" error.

Fix:
the two missing flags was added into collation initialization.

  Upgrade:

  - All fulltext indexes with custom UCA collations should be rebuilt.

  - Non-fulltext custom UCA indexes should likely be rebuild as well.

Remove size of binlog file from SHOW BINARY LOGS. 
Changing size of binlog file is an affect of adding or removing events to/from
binlog and it can be checked in next command of test: SHOW BINLOG EVENTS.
For SHOW BINARY LOGS statement enough to show the list of file names.