Allow keys with 0 segements in MyISAM

This fixed a bug in SELECT DISTINCT when all selected parts where constants. (Bug #3203)


myisam/mi_create.c:
  Allow keys with 0 segements.
mysql-test/r/myisam.result:
  Test for problem with SELECT DISTINCT
mysql-test/t/myisam.test:
  Test for problem with SELECT DISTINCT

1 files changed, 14 insertions, 0 deletions

diff --git a/mysql-test/t/myisam.test b/mysql-test/t/myisam.test
index 7302e5dfdda..59b86309d77 100644
--- a/mysql-test/t/myisam.test
+++ b/mysql-test/t/myisam.test
@@ -422,3 +422,17 @@ update t1 set b='b  ' where a > 1;
 delete from t1 where b='b';
 select a,concat(b,'.') from t1;
 drop table t1;
+
+#
+# Test keys with 0 segments. (Bug #3203)
+#
+create table t1 (a int not null);
+create table t2 (a int not null, primary key (a));
+insert into t1 values (1);
+insert into t2 values (1),(2);
+select sql_big_result distinct t1.a from t1,t2 order by t2.a;
+select distinct t1.a from t1,t2 order by t2.a;
+select sql_big_result distinct t1.a from t1,t2;
+explain select sql_big_result distinct t1.a from t1,t2 order by t2.a;
+explain select distinct t1.a from t1,t2 order by t2.a;
+drop table t1,t2;