code coverage for UNIONs

mysql-test/r/subselect.result:
  independent subquery with union
mysql-test/r/union.result:
  converting temporary table from HEAP to MyISAM
mysql-test/t/subselect.test:
  independent subquery with union
mysql-test/t/union.test:
  converting temporary table from HEAP to MyISAM

mysql-test/r/subselect.result

@@ -149,10 +149,10 @@ select (select a from t1 where t1.a=t2.b), a from t2;
 (select a from t1 where t1.a=t2.b)	a
 NULL	1
 NULL	2
-select (select a from t1), a from t2;
-(select a from t1)	a
-2	1
-2	2
+select (select a from t1), a, (select 1 union select 2 limit 1) from t2;
+(select a from t1)	a	(select 1 union select 2 limit 1)
+2	1	1
+2	2	1
 select (select a from t3), a from t2;
 (select a from t3)	a
 NULL	1

mysql-test/r/union.result

@@ -803,3 +803,23 @@ t1	CREATE TABLE `t1` (
   `test` char(5) character set latin2 NOT NULL default ''
 ) TYPE=MyISAM DEFAULT CHARSET=latin1
 drop table t1;
+create table t1 (s char(200));
+insert into t1 values (repeat("1",200));
+create table t2 select * from t1;
+insert into t2 select * from t1;
+insert into t1 select * from t2;
+insert into t2 select * from t1;
+insert into t1 select * from t2;
+insert into t2 select * from t1;
+set local tmp_table_size=1024;
+select count(*) from (select * from t1 union all select * from t2 order by 1) b;
+count(*)
+21
+select count(*) from t1;
+count(*)
+8
+select count(*) from t2;
+count(*)
+13
+drop table t1,t2;
+set local tmp_table_size=default;

mysql-test/t/subselect.test

@@ -67,7 +67,7 @@ insert into t4 values (4,8),(3,8),(5,9);
 select (select a from t1 where t1.a = a1) as a2, (select b from t2 where t2.b=a2) as a1;
 select (select a from t1 where t1.a=t2.a), a from t2;
 select (select a from t1 where t1.a=t2.b), a from t2;
-select (select a from t1), a from t2;
+select (select a from t1), a, (select 1 union select 2 limit 1) from t2;
 select (select a from t3), a from t2;
 select * from t2 where t2.a=(select a from t1);
 insert into t3 values (6),(7),(3);

mysql-test/t/union.test

@@ -306,8 +306,6 @@ drop table t1, t2;
 #
 # types conversions
 #
-
-
 create table t1 SELECT "a" as a UNION select "aa" as a;
 select * from t1;
 show create table t1;
@@ -417,3 +415,24 @@ create table t1 select _latin1"test" union select _latin2"testt" ;
 create table t1 select _latin2"test" union select _latin2"testt" ;
 show create table t1;
 drop table t1;
+
+#
+# conversion memory->disk table
+#
+#
+# conversion memory->disk table
+#
+create table t1 (s char(200));
+insert into t1 values (repeat("1",200));
+create table t2 select * from t1;
+insert into t2 select * from t1;
+insert into t1 select * from t2;
+insert into t2 select * from t1;
+insert into t1 select * from t2;
+insert into t2 select * from t1;
+set local tmp_table_size=1024;
+select count(*) from (select * from t1 union all select * from t2 order by 1) b;
+select count(*) from t1;
+select count(*) from t2;
+drop table t1,t2;
+set local tmp_table_size=default;