Fixed a use of non-initialised variable, cannot use NULL flags if RANGE == NO_MAX_RANGE or NO_MIN_RANGE, so need to check NULL flags after checking the RANGE isn't NO_MAX_RANGE

from mysql-next-mr-bar

```---------------------------------------------------------
revno: 2599.178.12
revision-id: alik@mysql.com-20080812161845-we7cx9f22yrghob1
committer: Alexander Nozdrin <alik@mysql.com>
branch nick: 6.0-rt-build
timestamp: Tue 2008-08-12 20:18:45 +0400
message:
  Fix memory leak.
```

---------------------------------------------------------

Fixed a few bugs in hex string generation, in call to val_str for partition expressions, also made code reusable for DEFAULT handling to fix BUG#48464 by introducing function get_cs_converted_string_value, added partition_utf8 test case for UTF8 outputs

Fixed such that we fail if using integer constants for character set fields, now need to have correct constant types

Fixed so that character set constants are encoded as hex strings in frm file, but as utf8 strings in the same manner as default values in show create table and information schema tables

Backport for 5.5

In non debug builds, the statements:
- SHOW PROCEDURE CODE
- SHOW FUNCTION CODE
used to fail with a "syntax error", which is misleading.

These statements have been changed to return the following error for non
debug builds:
ERROR HY000: The 'SHOW PROCEDURE|FUNCTION CODE' feature is disabled; you
need MySQL built with '--with-debug' to have it working

For debug builds (./configure --with-debug), nothing is changed.

Backport for 5.5

Backport to 5.5

BUG#48397, set key_part->length to key_part->store_length isn't correct, store_length is a bit longer

      
When the query cache is disabled, the server shouldn't attempt to take the 
query cache mutex.
                             
By using the command line option --query_cache_type=0, the user can disable
   
(backport from mysql-pe)

Re-Allowing sr_YU with a "deprecated" warning.

per-file comments:
  mysql-test/r/mysql_upgrade.result
     result updated
  mysql-test/t/mysql_upgrade.test
     --skip-verbose option added to the call

Fixed code review change to ensure that VALUES constants are of the same result type as the field they are constants for

Item_sum::set_aggregator() may be called multiple times during query preparation.
On subsequent calls: verify that the aggregator type is the same,
and re-use the existing Aggregator.