Fix sorting of NULL values (Should always be first)

Fix problem with HAVING and MAX() IS NOT NULL


Docs/manual.texi:
  Changelog & NULL usage with ORDER BY
client/mysqldump.c:
  Cleanup disable keys
mysql-test/r/distinct.result:
  Fix results after ORDER BY with NULL fix
mysql-test/r/group_by.result:
  Fix results after ORDER BY with NULL fix
mysql-test/r/having.result:
  Testcase for bug with HAVING
mysql-test/t/distinct.test:
  Test for DISTINCT + ORDER BY DESC bug
mysql-test/t/having.test:
  Test of HAVING and MAX IS NOT NULL
sql/filesort.cc:
  Fix sorting of NULL values (Should always be first)
sql/item.h:
  Fix problem with HAVING and MAX() IS NOT NULL
sql/item_sum.h:
  Fix problem with HAVING and MAX() IS NOT NULL
sql/opt_range.cc:
  Fix problem with HAVING and MAX() IS NOT NULL
sql/opt_range.h:
  Fix sorting of NULL values
sql/sql_select.cc:
  Fix sorting of ORDER BY ... DESC on NULL values.

1 files changed, 1 insertions, 4 deletions

diff --git a/sql/filesort.cc b/sql/filesort.cc
index a5f42d5731e..7e3d1c96f57 100644
--- a/sql/filesort.cc
+++ b/sql/filesort.cc
@@ -452,10 +452,7 @@ static void make_sortkey(register SORTPARAM *param,
       {
 	if (field->is_null())
 	{
-	  if (sort_field->reverse)
-	    bfill(to,sort_field->length+1,(char) 255);
-	  else
-	    bzero((char*) to,sort_field->length+1);
+	  bzero((char*) to,sort_field->length+1);
 	  to+= sort_field->length+1;
 	  continue;
 	}