Change of internal key_field=NULL handling to avoid error messages.

Optimized SELECT DISTINCT ... ORDER BY ... LIMIT
Fixed reference to uninitalized variable

1 files changed, 10 insertions, 0 deletions

diff --git a/mysql-test/t/distinct.test b/mysql-test/t/distinct.test
index aaffea3c5a5..7f75b6b1687 100644
--- a/mysql-test/t/distinct.test
+++ b/mysql-test/t/distinct.test
@@ -88,6 +88,16 @@ select distinct t1.a from t1,t3 where t1.a=t3.a;
 #flush status;
 select distinct 1 from t1,t3 where t1.a=t3.a;
 #show status like 'Handler%';
+
+explain SELECT distinct t1.a from t1;
+explain SELECT distinct t1.a from t1 order by a desc;
+explain SELECT t1.a from t1 group by a order by a desc;
+explain SELECT distinct t1.a from t1 order by a desc limit 1;
+explain SELECT distinct a from t3 order by a desc limit 2;
+explain SELECT distinct a,b from t3 order by a+1;
+explain SELECT distinct a,b from t3 order by a limit 10;
+explain SELECT a,b from t3 group by a,b order by a+1;
+
 drop table t1,t2,t3,t4;
 
 CREATE TABLE t1 (name varchar(255));