into  a193-229-222-105.elisa-laajakaista.fi:/home/my/bk/mysql-5.1-new-merge_060509

into  mysql.com:/home/psergey/mysql-5.1-merge5

into  mysql.com:/home/psergey/mysql-5.1-merge5

into  mysql.com:/home/ndbdev/jmiller/clones/mysql-5.1-new

into  a193-229-222-105.elisa-laajakaista.fi:/home/my/bk/mysql-5.1-new-merge_060509

into  mysql.com:/home/tomash/src/mysql_ab/mysql-5.1-merge

into  a193-229-222-105.elisa-laajakaista.fi:/home/my/bk/mysql-5.1-new-merge_060509

into  mysql.com:/home/ndbdev/jmiller/clones/mysql-5.1-new

  Remove comments not needed

  Correct fix for test bug #19158

into  neptunus.(none):/home/msvensson/mysql/mysql-5.1

into  neptunus.(none):/home/msvensson/mysql/mysql-5.1

into  neptunus.(none):/home/msvensson/mysql/mysql-5.1

by a dirty word, and it complains about it, even in a comment.

into mysql.com:/M51/mysql-5.1

into sergbook.mysql.com:/usr/home/serg/Abk/mysql-5.1

into mysql.com:/M51/mysql-5.1

into  neptunus.(none):/home/msvensson/mysql/mysql-5.1

into  neptunus.(none):/home/msvensson/mysql/mysql-5.1

into  ua141d10.elisa.omakaista.fi:/home/my/bk/mysql-5.1-new

into  ua141d10.elisa.omakaista.fi:/home/my/bk/mysql-5.1-new

into  mysql.com:/home/kgeorge/mysql/5.1/B18068

When converting DISTINCT to GROUP BY where the columns are from the covering
index and they are quoted twice in the SELECT list the optimizer is creating
improper processing sequence. This is because of the fact that the columns
of the covering index are not recognized as such and treated as non-index
columns.

Generally speaking duplicate columns can safely be removed from the GROUP
BY/DISTINCT list because this will not add or remove new rows in the
resulting set. Duplicates can be removed even if they are not consecutive
(as is the case for ORDER BY, where the duplicate columns can be removed
only if they are consecutive).

So we can safely transform "SELECT DISTINCT a,a FROM ... ORDER BY a" to
"SELECT a,a FROM ... GROUP BY a ORDER BY a" instead of 
"SELECT a,a FROM .. GROUP BY a,a ORDER BY a". We can even transform 
"SELECT DISTINCT a,b,a FROM ... ORDER BY a,b" to
"SELECT a,b,a FROM ... GROUP BY a,b ORDER BY a,b".

The fix to this bug consists of checking for duplicate columns in the SELECT
list when constructing the GROUP BY list in transforming DISTINCT to GROUP
BY and skipping the ones that are already in.

into  neptunus.(none):/home/msvensson/mysql/mysql-5.1

into  ua141d10.elisa.omakaista.fi:/home/my/bk/mysql-5.1-new

into  mysql.com:/home/marty/MySQL/mysql-5.0

into  mysql.com:/home/marty/MySQL/mysql-5.0