1. Fix ddl_i18n_koi8r, ddl_i18n_utf8: explicitly specify character-sets
directory for mysqldump;
2. Fix crash in mysqldump if collation is not found;
3. Use proper way to compare character set names.

  - BUG#11986: Stored routines and triggers can fail if the code
    has a non-ascii symbol
  - BUG#16291: mysqldump corrupts string-constants with non-ascii-chars
  - BUG#19443: INFORMATION_SCHEMA does not support charsets properly
  - BUG#21249: Character set of SP-var can be ignored
  - BUG#25212: Character set of string constant is ignored (stored routines)
  - BUG#25221: Character set of string constant is ignored (triggers)

There were a few general problems that caused these bugs:
1. Character set information of the original (definition) query for views,
   triggers, stored routines and events was lost.
2. mysqldump output query in client character set, which can be
   inappropriate to encode definition-query.
3. INFORMATION_SCHEMA used strings with mixed encodings to display object
   definition;

1. No query-definition-character set.

In order to compile query into execution code, some extra data (such as
environment variables or the database character set) is used. The problem
here was that this context was not preserved. So, on the next load it can
differ from the original one, thus the result will be different.

The context contains the following data:
  - client character set;
  - connection collation (character set and collation);
  - collation of the owner database;

The fix is to store this context and use it each time we parse (compile)
and execute the object (stored routine, trigger, ...).

2. Wrong mysqldump-output.

The original query can contain several encodings (by means of character set
introducers). The problem here was that we tried to convert original query
to the mysqldump-client character set.

Moreover, we stored queries in different character sets for different
objects (views, for one, used UTF8, triggers used original character set).

The solution is
  - to store definition queries in the original character set;
  - to change SHOW CREATE statement to output definition query in the
    binary character set (i.e. without any conversion);
  - introduce SHOW CREATE TRIGGER statement;
  - to dump special statements to switch the context to the original one
    before dumping and restore it afterwards.

Note, in order to preserve the database collation at the creation time,
additional ALTER DATABASE might be used (to temporary switch the database
collation back to the original value). In this case, ALTER DATABASE
privilege will be required. This is a backward-incompatible change.

3. INFORMATION_SCHEMA showed non-UTF8 strings

The fix is to generate UTF8-query during the parsing, store it in the object
and show it in the INFORMATION_SCHEMA.

Basically, the idea is to create a copy of the original query convert it to
UTF8. Character set introducers are removed and all text literals are
converted to UTF8.

This UTF8 query is intended to provide user-readable output. It must not be
used to recreate the object.  Specialized SHOW CREATE statements should be
used for this.

The reason for this limitation is the following: the original query can
contain symbols from several character sets (by means of character set
introducers).

Example:

  - original query:
    CREATE VIEW v1 AS SELECT _cp1251 'Hello' AS c1;

  - UTF8 query (for INFORMATION_SCHEMA):
    CREATE VIEW v1 AS SELECT 'Hello' AS c1;

into  weblab.(none):/home/marcsql/TREE/mysql-5.1-rt-merge

into  weblab.(none):/home/marcsql/TREE/mysql-5.1-rt-merge

into  gleb.loc:/home/uchum/work/bk/5.1-opt

into  gleb.loc:/home/uchum/work/bk/5.1-opt

into  mysql.com:/home/hf/work/27084/my51-27084

into  gleb.loc:/home/uchum/work/bk/5.1-opt

into  gleb.loc:/home/uchum/work/bk/5.0-opt

into  gleb.loc:/home/uchum/work/bk/5.0-opt

into  gleb.loc:/home/uchum/work/bk/5.1-opt

into  gleb.loc:/home/uchum/work/bk/4.1-opt

into  olga.mysql.com:/home/igor/mysql-5.1-opt

  Merge with 5.1.

into  gleb.loc:/home/uchum/work/bk/5.1-opt

into  olga.mysql.com:/home/igor/dev-opt/mysql-5.0-opt-bug25602

into  gleb.loc:/home/uchum/work/bk/5.0-opt

the loose scan optimization for grouping queries was applied returned 
a wrong result set when the query was used with the SQL_BIG_RESULT
option.

The SQL_BIG_RESULT option forces to use sorting algorithm for grouping
queries instead of employing a suitable index. The current loose scan
optimization is applied only for one table queries when the suitable
index is covering. It does not make sense to use sort algorithm in this
case. However the create_sort_index function does not take into account
the possible choice of the loose scan to implement the DISTINCT operator
which makes sorting unnecessary. Moreover the current implementation of
the loose scan for queries with distinct assumes that sorting will
never happen. Thus in this case create_sort_index should not call
the function filesort.

into  gleb.loc:/home/uchum/work/bk/5.1-opt

into  gleb.loc:/home/uchum/work/bk/5.0-opt

into  gleb.loc:/home/uchum/work/bk/5.1-opt

into  gleb.loc:/home/uchum/work/bk/5.0-opt

INSERT into table from SELECT from the same table
with ORDER BY and LIMIT was inserting other data
than sole SELECT ... ORDER BY ... LIMIT returns.

One part of the patch for bug #9676 improperly pushed
LIMIT to temporary table in the presence of the ORDER BY
clause.
That part has been removed.

parameter don't use query cache"
Thanks to the fix of BUG#26842, statements prepared with SQL PREPARE
and having parameters can now use the query cache.

into  trift2.:/MySQL/M51/push-5.1

into  trift2.:/MySQL/M51/push-5.1

into  trift2.:/MySQL/M50/push-5.0

into  trift2.:/MySQL/M51/push-5.1

into  maint1.mysql.com:/data/localhome/tsmith/bk/maint/51

to be run only if it is available on the machine.

The embedded library is still broken, but there the situation
with dependencies is even more broken.

into  adventure.(none):/home/thek/Development/cpp/mysql-5.1-runtime

- Manual merge patch.

into  adventure.(none):/home/thek/Development/cpp/bug28846/my51-bug28846

into  magare.gmz:/home/kgeorge/mysql/autopush/B28400-5.0-opt

The C optimizer may decide that data access operations
through pointer of different type are not related to 
the original data (strict aliasing).
This is what happens in fetch_long_with_conversion(),
when called as part of mysql_stmt_fetch() : it tries 
to check for truncation errors by first storing float
(and other types of data) into a char * buffer and then 
accesses them through a float pointer.
This is done to prevent the effects of excess precision
when using FPU registers.
However the doublestore() macro converts a double pointer
to an union pointer. This violates the strict aliasing rule.
Fixed by making the intermediary variables volatile (
to not re-introduce the excess precision bug) and using
the intermediary value instead of the char * buffer.
Note that there can be loss of precision for both signed
and unsigned 64 bit integers converted to double and back,
so the check must stay there (even for compatibility 
reasons).
Based on the excellent analysis in bug 28400.

into  trift2.:/MySQL/M51/push-5.1