sql_union.cc, sql_select.cc:

  Code clean-up
sql_union.cc, union.test, union.result:
  A fix for a bug #978.
  This enables that NULL's can be entered into UNION's result set,
  although first SELECT columns are NOT NULL.
  This is also a start of fixing UNION's properly regarding type
  acceptance.
sql_select.cc:
  A commit for my second July SPRINT task


mysql-test/r/union.result:
  A fix for a bug #978.
  
  This enables that NULL's can be entered into UNION's result set,
  although first SELECT columns are NOT NULL.
  
  This is also a start of fixing UNION's properly regarding type
  acceptance.
mysql-test/t/union.test:
  A fix for a bug #978.
  
  This enables that NULL's can be entered into UNION's result set,
  although first SELECT columns are NOT NULL.
  
  This is also a start of fixing UNION's properly regarding type
  acceptance.
sql/sql_select.cc:
  Code clean-up
sql/sql_union.cc:
  Code clean-up

2 files changed, 22 insertions, 0 deletions

diff --git a/mysql-test/r/union.result b/mysql-test/r/union.result
index 5b7b26bc1bb..6d8bd263546 100644
--- a/mysql-test/r/union.result
+++ b/mysql-test/r/union.result
@@ -328,3 +328,16 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	PRIMARY	t1	const	PRIMARY	PRIMARY	4	const	1	
 2	UNION	t1	ref	b	b	5	const	1	Using where
 drop table t1,t2;
+create table t1 (   id int not null auto_increment, primary key (id)   ,user_name text );
+create table t2 (    id int not null auto_increment, primary key (id)   ,group_name text );
+create table t3 (    id int not null auto_increment, primary key (id)   ,user_id int   ,index user_idx (user_id)   ,foreign key (user_id) references users(id)   ,group_id int   ,index group_idx (group_id)   ,foreign key (group_id) references groups(id) );
+insert into t1 (user_name) values ('Tester');
+insert into t2 (group_name) values ('Group A');
+insert into t2 (group_name) values ('Group B');
+insert into t3 (user_id, group_id) values (1,1);
+select 1 'is_in_group', a.user_name, c.group_name, b.id from t1 a, t3 b, t2 c where a.id = b.user_id and b.group_id = c.id UNION  select 0 'is_in_group', a.user_name, c.group_name, null from t1 a, t2 c;
+is_in_group	user_name	group_name	id
+1	Tester	Group A	1
+0	Tester	Group A	NULL
+0	Tester	Group B	NULL
+drop table t1, t2, t3;
diff --git a/mysql-test/t/union.test b/mysql-test/t/union.test
index 6d857a4b40f..aeea27ade0f 100644
--- a/mysql-test/t/union.test
+++ b/mysql-test/t/union.test
@@ -209,3 +209,12 @@ explain (select * from t1 where a=1) union (select * from t2 where a=1);
 explain (select * from t1 where a=1 and b=10) union (select t1.a,t2.a from t1,t2 where t1.a=t2.a);
 explain (select * from t1 where a=1) union (select * from t1 where b=1);
 drop table t1,t2;
+create table t1 (   id int not null auto_increment, primary key (id)   ,user_name text );
+create table t2 (    id int not null auto_increment, primary key (id)   ,group_name text );
+create table t3 (    id int not null auto_increment, primary key (id)   ,user_id int   ,index user_idx (user_id)   ,foreign key (user_id) references users(id)   ,group_id int   ,index group_idx (group_id)   ,foreign key (group_id) references groups(id) );
+insert into t1 (user_name) values ('Tester');
+insert into t2 (group_name) values ('Group A');
+insert into t2 (group_name) values ('Group B');
+insert into t3 (user_id, group_id) values (1,1);
+select 1 'is_in_group', a.user_name, c.group_name, b.id from t1 a, t3 b, t2 c where a.id = b.user_id and b.group_id = c.id UNION  select 0 'is_in_group', a.user_name, c.group_name, null from t1 a, t2 c;
+drop table t1, t2, t3;