Fixed some possible race conditions when doing many reopen/close on the same tables under heavy load! This can happen if you execute mysqladmin refresh often. This could in some very rare cases corrupt the header of the index file and cause error 126 or 138.

Fixed fatal bug in refresh() when running with the --skip-external-locking option. There was a ``very small'' time gap after a mysqladmin refresh when a table could be corrupted if one thread updated a table while another thread did mysqladmin refresh and another thread started a new update ont the same table before the first thread had finished. A refresh (or --flush-tables) will now not return until all used tables are closed!

SELECT DISTINCT with a WHERE clause that didn't match any rows returned a row in some contexts (bug only in 3.21.31).

GROUP BY + ORDER BY returned one empty row when no rows where found.

Fixed a bug in the range optimizer that wrote Use_count: Wrong count for ... in the error log file.