Bug #42279  	Race condition in btr_search_drop_page_hash_when_freed()

Detailed revision comments:

r4032 | marko | 2009-01-23 15:43:51 +0200 (Fri, 23 Jan 2009) | 10 lines
branches/5.1: Merge r4031 from branches/5.0:

btr_search_drop_page_hash_when_freed(): Check if buf_page_get_gen()
returns NULL.  The page may have been evicted from the buffer pool
between buf_page_peek_if_search_hashed() and buf_page_get_gen(),
because the buffer pool mutex will be released between these two calls.
(Bug #42279)

rb://82 approved by Heikki Tuuri

Since there is more than one duplicate value in the table, when adding the
unique index it is not deterministic which value will be reported as causing a
problem.  Replace the reported value with '' so that it doesn't affect the
results.

The problem is that creating a event could fail if the value of
the variable server_id didn't fit in the originator column of
the event system table. The cause is two-fold: it was possible
to set server_id to a value outside the documented range (from
0 to 2^32-1) and the originator column of the event table didn't
have enough room for values in this range.

The log tables (general_log and slow_log) also don't have a proper
column type to store the server_id and having a large server_id
value could prevent queries from being logged.

The solution is to ensure that all system tables that store the
server_id value have a proper column type (int unsigned) and that
the variable can't be set to a value that is not within the range.

      
The copy of the original arguments of a aggregate function was not
initialized until after fix_fields().
Sometimes (e.g. when there's an error processing the statement)
the print() can be called with no corresponding fix_fields() call.
      
Fixed by adding a check if the Item is fixed before using the arguments
copy.

The method to purge binary log files produces different results in some platforms.
The reason is that the purge time is calculated based on table modified time and
that can't guarantee to purge master-bin.000002 in all platforms.(eg. windows)

Use a new way that sets the time to purge binlog file 1 second after the last modified time of master-bin.000002.
That can be sure that the file is always deleted in any platform.

Took the Xfree implementation (based on the same rewrite as the NDB one)
and added it instead of the current implementation.
Added a macro to make the calls to MD5 more streamlined. 

Changes are due to changes in precision.
Re-record of .result files to account for new server precision.

test-fixes for 32-bit

Would not prevent mysqld from core dumping
Passes --nocore arg to safe_process, which then sets rlimit core to 0 for child

Retried tests are reported the same as ordinary ones
Prepend "retry-" to fail or pass for retried tests