Add support for NULL=NULL in keys (Used in GROUP BY optimization)

Add ISAM to Windows version
Fix of test results
Fixes for NULL keys in HEAP tables.

4 files changed, 110 insertions, 4 deletions

diff --git a/mysql-test/r/group_by.result b/mysql-test/r/group_by.result
index a0e234aa69c..a67298c73c0 100644
--- a/mysql-test/r/group_by.result
+++ b/mysql-test/r/group_by.result
@@ -263,3 +263,84 @@ score	count(*)
 2	1
 1	2
 drop table t1;
+CREATE TABLE t1 (a char(1));
+INSERT INTO t1 VALUES ('A'),('B'),('A'),('B'),('A'),('B'),(NULL),('a'),('b'),(NULL),('A'),('B'),(NULL);
+SELECT a FROM t1 GROUP BY a;
+a
+NULL
+A
+B
+SELECT a,count(*) FROM t1 GROUP BY a;
+a	count(*)
+NULL	3
+A	5
+B	5
+SELECT a FROM t1 GROUP BY binary a;
+a
+NULL
+A
+B
+a
+b
+SELECT a,count(*) FROM t1 GROUP BY binary a;
+a	count(*)
+NULL	3
+A	4
+B	4
+a	1
+b	1
+SELECT binary a FROM t1 GROUP BY 1;
+binary a
+NULL
+A
+B
+a
+b
+SELECT binary a,count(*) FROM t1 GROUP BY 1;
+binary a	count(*)
+NULL	3
+A	4
+B	4
+a	1
+b	1
+SET SQL_BIG_TABLES=1;
+SELECT a FROM t1 GROUP BY a;
+a
+NULL
+A
+B
+SELECT a,count(*) FROM t1 GROUP BY a;
+a	count(*)
+NULL	3
+A	5
+B	5
+SELECT a FROM t1 GROUP BY binary a;
+a
+NULL
+A
+B
+a
+b
+SELECT a,count(*) FROM t1 GROUP BY binary a;
+a	count(*)
+NULL	3
+A	4
+B	4
+a	1
+b	1
+SELECT binary a FROM t1 GROUP BY 1;
+binary a
+NULL
+A
+B
+a
+b
+SELECT binary a,count(*) FROM t1 GROUP BY 1;
+binary a	count(*)
+NULL	3
+A	4
+B	4
+a	1
+b	1
+SET SQL_BIG_TABLES=0;
+drop table t1;
diff --git a/mysql-test/r/heap.result b/mysql-test/r/heap.result
index 5495997324a..fc4a116307e 100644
--- a/mysql-test/r/heap.result
+++ b/mysql-test/r/heap.result
@@ -165,3 +165,29 @@ explain select * from t1 where btn="a" and new_col="a";
 table	type	possible_keys	key	key_len	ref	rows	Extra
 t1	ref	btn	btn	11	const,const	10	where used
 drop table t1;
+CREATE TABLE t1 (
+a int default NULL,
+b int default NULL,
+KEY a (a),
+UNIQUE b (b)
+) type=heap;
+INSERT INTO t1 VALUES (NULL,99),(99,NULL),(1,1),(2,2),(1,3);
+SELECT * FROM t1 WHERE a=NULL;
+a	b
+explain SELECT * FROM t1 WHERE a IS NULL;
+table	type	possible_keys	key	key_len	ref	rows	Extra
+t1	ref	a	a	5	const	10	where used
+SELECT * FROM t1 WHERE a<=>NULL;
+a	b
+NULL	99
+SELECT * FROM t1 WHERE b=NULL;
+a	b
+explain SELECT * FROM t1 WHERE b IS NULL;
+table	type	possible_keys	key	key_len	ref	rows	Extra
+t1	ref	b	b	5	const	1	where used
+SELECT * FROM t1 WHERE b<=>NULL;
+a	b
+99	NULL
+INSERT INTO t1 VALUES (1,3);
+Duplicate entry '3' for key 1
+DROP TABLE t1;
diff --git a/mysql-test/r/null.result b/mysql-test/r/null.result
index 77f2c67bf05..e6e3b7155a3 100644
--- a/mysql-test/r/null.result
+++ b/mysql-test/r/null.result
@@ -40,7 +40,6 @@ insert into t1 values (null);
 select * from t1 where x != 0;
 x
 drop table t1;
-DROP TABLE IF EXISTS t1;
 CREATE TABLE t1 (
 indexed_field int default NULL,
 KEY indexed_field (indexed_field)
diff --git a/mysql-test/r/order_by.result b/mysql-test/r/order_by.result
index a9d18e838cb..9bc716ee8b9 100644
--- a/mysql-test/r/order_by.result
+++ b/mysql-test/r/order_by.result
@@ -286,15 +286,15 @@ a	b	c
 1	NULL	NULL
 explain select * from t1 where a = 1 order by a desc, b desc;
 table	type	possible_keys	key	key_len	ref	rows	Extra
-t1	ref	a	a	4	const	5	where used; Using index; Using filesort
+t1	ref	a	a	4	const	5	where used; Using index
 select * from t1 where a = 1 order by a desc, b desc;
 a	b	c
 1	3	b
-1	1	NULL
 1	1	b
 1	1	b
-1	NULL	NULL
+1	1	NULL
 1	NULL	b
+1	NULL	NULL
 explain select * from t1 where a = 1 and b is null order by a desc, b desc;
 table	type	possible_keys	key	key_len	ref	rows	Extra
 t1	ref	a	a	9	const,const	2	where used; Using index; Using filesort