removed wrong distinct UNION detection (BUG#6565)

mysql-test/r/derived.result:
  test of union subquery in the FROM clause with complex distinct/all
mysql-test/t/derived.test:
  test of union subquery in the FROM clause with complex distinct/all
sql/sql_derived.cc:
  removed wrong distinct UNION detection

1 files changed, 12 insertions, 0 deletions

diff --git a/mysql-test/t/derived.test b/mysql-test/t/derived.test
index 8b322746ed6..bd27e0654e0 100644
--- a/mysql-test/t/derived.test
+++ b/mysql-test/t/derived.test
@@ -224,3 +224,15 @@ select distinct sum(b) from t1 group by a;
 select distinct sum(b) from (select a,b from t1) y group by a;
 drop table t1;
 
+#
+# test of union subquery in the FROM clause with complex distinct/all (BUG#6565)
+#
+create table t1(a int);
+create table t2(a int);
+create table t3(a int);
+insert into t1 values(1),(1);
+insert into t2 values(2),(2);
+insert into t3 values(3),(3);
+select * from t1 union distinct select * from t2 union all select * from t3;
+select * from (select * from t1 union distinct select * from t2 union all select * from t3) X;
+drop table t1, t2, t3;