Merge olga.mysql.com:/home/igor/mysql-5.0-opt

into  olga.mysql.com:/home/igor/mysql-5.1-opt

mysql-test/r/subselect3.result

@@ -711,3 +711,34 @@ a
 1
 4
 DROP TABLE t1,t2;
+CREATE TABLE t1 (id int);
+CREATE TABLE t2 (id int PRIMARY KEY);
+CREATE TABLE t3 (id int PRIMARY KEY, name varchar(10));
+INSERT INTO t1 VALUES (2), (NULL), (3), (1);
+INSERT INTO t2 VALUES (234), (345), (457);
+INSERT INTO t3 VALUES (222,'bbb'), (333,'ccc'), (111,'aaa');
+EXPLAIN
+SELECT * FROM t1
+WHERE t1.id NOT IN (SELECT t2.id FROM t2,t3 
+WHERE t3.name='xxx' AND t2.id=t3.id);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	t1	ALL	NULL	NULL	NULL	NULL	4	Using where
+2	DEPENDENT SUBQUERY	t2	eq_ref	PRIMARY	PRIMARY	4	func	1	Using where; Using index; Full scan on NULL key
+2	DEPENDENT SUBQUERY	t3	eq_ref	PRIMARY	PRIMARY	4	func	1	Using where; Full scan on NULL key
+SELECT * FROM t1
+WHERE t1.id NOT IN (SELECT t2.id FROM t2,t3 
+WHERE t3.name='xxx' AND t2.id=t3.id);
+id
+2
+NULL
+3
+1
+SELECT (t1.id IN (SELECT t2.id FROM t2,t3 
+WHERE t3.name='xxx' AND t2.id=t3.id)) AS x
+FROM t1;
+x
+0
+0
+0
+0
+DROP TABLE t1,t2,t3;

mysql-test/t/subselect3.test

@@ -546,3 +546,28 @@ SELECT a FROM t1, t2 WHERE a=b AND (b NOT IN (SELECT a FROM t1));
 SELECT a FROM t1, t2 WHERE a=b AND (b NOT IN (SELECT a FROM t1 WHERE a > 4));
 
 DROP TABLE t1,t2;
+
+#
+# Bug #28375: crash for NOT IN subquery predicate when left operand becomes NULL  
+#
+
+CREATE TABLE t1 (id int);
+CREATE TABLE t2 (id int PRIMARY KEY);
+CREATE TABLE t3 (id int PRIMARY KEY, name varchar(10));
+INSERT INTO t1 VALUES (2), (NULL), (3), (1);
+INSERT INTO t2 VALUES (234), (345), (457);
+INSERT INTO t3 VALUES (222,'bbb'), (333,'ccc'), (111,'aaa');
+
+EXPLAIN
+SELECT * FROM t1
+  WHERE t1.id NOT IN (SELECT t2.id FROM t2,t3 
+                        WHERE t3.name='xxx' AND t2.id=t3.id);
+SELECT * FROM t1
+  WHERE t1.id NOT IN (SELECT t2.id FROM t2,t3 
+                        WHERE t3.name='xxx' AND t2.id=t3.id);
+
+SELECT (t1.id IN (SELECT t2.id FROM t2,t3 
+                    WHERE t3.name='xxx' AND t2.id=t3.id)) AS x
+  FROM t1;
+
+DROP TABLE t1,t2,t3;   

sql/item_subselect.cc

@@ -1872,6 +1872,8 @@ int subselect_single_select_engine::exec()
             if (cond_guard && !*cond_guard)
             {
               /* Change the access method to full table scan */
+              tab->save_read_first_record= tab->read_first_record;
+              tab->save_read_record= tab->read_record.read_record;
               tab->read_first_record= init_read_record_seq;
               tab->read_record.record= tab->table->record[0];
               tab->read_record.thd= join->thd;
@@ -1892,8 +1894,8 @@ int subselect_single_select_engine::exec()
       JOIN_TAB *tab= *ptab;
       tab->read_record.record= 0;
       tab->read_record.ref_length= 0;
-      tab->read_first_record= join_read_always_key_or_null;
-      tab->read_record.read_record= join_read_next_same_or_null;
+      tab->read_first_record= tab->save_read_first_record; 
+      tab->read_record.read_record= tab->save_read_record;
     }
     executed= 1;
     thd->where= save_where;

sql/sql_select.h

@@ -160,6 +160,13 @@ typedef struct st_join_table {
   Read_record_func read_first_record;
   Next_select_func next_select;
   READ_RECORD	read_record;
+  /* 
+    Currently the following two fields are used only for a [NOT] IN subquery
+    if it is executed by an alternative full table scan when the left operand of
+    the subquery predicate is evaluated to NULL.
+  */  
+  Read_record_func save_read_first_record;/* to save read_first_record */ 
+  int (*save_read_record) (READ_RECORD *);/* to save read_record.read_record */
   double	worst_seeks;
   key_map	const_keys;			/* Keys with constant part */
   key_map	checked_keys;			/* Keys checked in find_best */