INSERT IGNORE ... SELECT ... UNION SELECT ...

This assert was triggered by INSERT IGNORE ... SELECT. The assert checks that a
statement either sends OK or an error to the client. If the bug was triggered
on release builds, it caused OK to be sent to the client instead of the correct
error message (in this case ER_FIELD_SPECIFIED_TWICE).

The reason the assert was triggered, was that lex->no_error was set to TRUE
during JOIN::optimize() because of IGNORE. This causes all errors to be ignored.
However, not all errors can be ignored. Some, such as ER_FIELD_SPECIFIED_TWICE
will cause the INSERT to fail no matter what. But since lex->no_error was set,
the critical errors were ignored, the INSERT failed and neither OK nor the
error message was sent to the client.

This patch fixes the problem by temporarily turning off lex->no_error in
places where errors cannot be ignored during processing of INSERT ... SELECT.

Test case added to insert.test.

read_rnd_buffer_size

Applied the updated description from Paul's patch.

Undo workaround as fix is being merged in

failures on sparc64.

file .\item_subselect.cc, line 836

IN quantified predicates are never executed directly. They are rather wrapped
inside nodes called IN Optimizers (Item_in_optimizer) which take care of the
execution. However, this is not done during query preparation. Unfortunately
the LIKE predicate pre-evaluates constant right-hand side arguments even
during name resolution. Likely this is meant as an optimization.

Fixed by not pre-evaluating LIKE arguments in view prepare mode.

Reverted the ulong->uint diff
Re-applied the first diff.
The original commit message follows:

enum plugin system variables are ulong internally, not int.
On systems where long is not the same as an int it causes
problems. 
Fixed by correct typecasting. Removed the test from the 
experimental list.

Follow-up patch: added test cases for -0 and while

The enum system variables were handled inconsistently 
as ints, unsigned int and unsigned long on various places.
This caused problems on platforms on which 
sizeof(int) != sizeof(long).
Fixed by homogenizing the type of the enum variables
to unsigned int, since it's size compatible with the C enum
type. 
Removed the test from the experimental list.

if() treated any non-numeric string as false
Fixed to treat those as true instead
Added some test cases
Fixed missing $ in variable name in include/mix2.inc

Post fix

Post fix

      
With statement- or mixed-mode logging, "LOAD DATA INFILE" queries
are written to the binlog using special types of log events.
When mysqlbinlog reads such events, it re-creates the file in a
temporary directory with a generated filename and outputs a
"LOAD DATA INFILE" query where the filename is replaced by the
generated file. The temporary file is not deleted by mysqlbinlog
after termination.
      
To fix the problem, in mixed mode we go to row-based. In SBR, we
document it to remind user the tmpfile is left in a temporary
directory.

With statement- or mixed-mode logging, "LOAD DATA INFILE" queries
are written to the binlog using special types of log events.
When mysqlbinlog reads such events, it re-creates the file in a
temporary directory with a generated filename and outputs a
"LOAD DATA INFILE" query where the filename is replaced by the
generated file. The temporary file is not deleted by mysqlbinlog
after termination.

To fix the problem, in mixed mode we go to row-based. In SBR, we
document it to remind user the tmpfile is left in a temporary
directory.

The expect file can now include "restart:<server options>"
Also drop check-testcase if this has been done
Added comment explaining the restart: syntax

scripts if cmake is available. We need to always generate the
scripts in order for the dual cmake/autotools support to work.

Fix compiler warnings.

******
This patch fixes the following bugs:
  - Bug#5889: Exit handler for a warning doesn't hide the warning in
    trigger
  - Bug#9857: Stored procedures: handler for sqlwarning ignored
  - Bug#23032: Handlers declared in a SP do not handle warnings generated
    in sub-SP
  - Bug#36185: Incorrect precedence for warning and exception handlers

The problem was in the way warnings/errors during stored routine execution
were handled. Prior to this patch the logic was as follows:

  - when a warning/an error happens: if we're executing a stored routine,
    and there is a handler for that warning/error, remember the handler,
    ignore the warning/error and continue execution.

  - after a stored routine instruction is executed: check for a remembered
    handler and activate one (if any).

This logic caused several problems:

  - if one instruction generates several warnings (errors) it's impossible
    to choose the right handler -- a handler for the first generated
    condition was chosen and remembered for activation.

  - mess with handling conditions in scopes different from the current one.

  - not putting generated warnings/errors into Warning Info (Diagnostic
    Area) is against The Standard.

The patch changes the logic as follows:

  - Diagnostic Area is cleared on the beginning of each statement that
    either is able to generate warnings, or is able to work with tables.

  - at the end of a stored routine instruction, Diagnostic Area is left
    intact.

  - Diagnostic Area is checked after each stored routine instruction. If
    an instruction generates several condition, it's now possible to take a
    look at all of them and determine an appropriate handler.

Revert BUG#34283.

Conflicts
=========
  Text conflict in sql/sql_load.cc
  1 conflicts encountered.

mostly because existing test result files were not updated.

In order to be able to check if the set of the grouping fields in a 
GROUP BY has changed (and thus to start a new group) the optimizer
caches the current values of these fields in a set of Cached_item 
derived objects.
The Cached_item_str, used for caching varchar and TEXT columns,
is limited in length by the max_sort_length variable.
A String buffer to store the value with an alloced length of either
the max length of the string or the value of max_sort_length 
(whichever is smaller) in Cached_item_str's constructor.
Then, at compare time the value of the string to compare to was 
truncated to the alloced length of the string buffer inside 
Cached_item_str.
This is all fine and valid, but only if you're not assigning 
values near or equal to the alloced length of this buffer.
Because when assigning values like this the alloced length is 
rounded up and as a result the next set of data will not match the
group buffer, thus leading to wrong results because of the changed
alloced_length.
Fixed by preserving the original maximum length in the 
Cached_item_str's constructor and using this instead of the 
alloced_length to limit the string to compare to.
Test case added.