bk commit into 4.1 tree (igor:1.2532) BUG#23478

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ChangeSet@stripped, 2006-10-19 23:02:11-07:00, igor@stripped +2 -0
  Fixed bug #23478.
  If elements a not top-level IN subquery were accessed by an index and 
  the subquery result set included  a NULL value then the quantified
  predicate that contained the subquery was evaluated to NULL when 
  it should return a non-null value.

  mysql-test/t/subselect.test@stripped, 2006-10-19 23:02:09-07:00, igor@stripped +17
-0
    Added a test case for bug #23478.

  sql/item_subselect.cc@stripped, 2006-10-19 23:02:09-07:00, igor@stripped +3 -0
    Fixed bug #23478.
    If elements a not top-level IN subquery were accessed by an index and 
    the subquery result set included  a NULL value then the quantified
    predicate that contained the subquery was evaluated to NULL when 
    it should return a non-null value.

# This is a BitKeeper patch.  What follows are the unified diffs for the
# set of deltas contained in the patch.  The rest of the patch, the part
# that BitKeeper cares about, is below these diffs.
# User:	igor
# Host:	rurik.mysql.com
# Root:	/home/igor/dev-opt/mysql-4.1-opt-bug23478

--- 1.160/mysql-test/t/subselect.test	2006-10-19 23:02:16 -07:00
+++ 1.161/mysql-test/t/subselect.test	2006-10-19 23:02:16 -07:00
@@ -1948,4 +1948,21 @@
 
 DROP TABLE t1, t2;
 
+#
+# Bug #23478: not top-level IN subquery returning a non-empty result set
+#             with possible NULL values by index access from the outer query
+#
+
+CREATE TABLE t1(a int, INDEX (a));
+INSERT INTO t1 VALUES (1), (3), (5), (7);
+INSERT INTO t1 VALUES (NULL);
+
+CREATE TABLE t2(a int);
+INSERT INTO t2 VALUES (1),(2),(3);
+
+EXPLAIN SELECT a, a IN (SELECT a FROM t1) FROM t2;
+SELECT a, a IN (SELECT a FROM t1) FROM t2;
+
+DROP TABLE t1,t2;
+
 # End of 4.1 tests

--- 1.144/sql/item_subselect.cc	2006-10-19 23:02:16 -07:00
+++ 1.145/sql/item_subselect.cc	2006-10-19 23:02:16 -07:00
@@ -610,6 +610,7 @@
   */
   DBUG_ASSERT(0);
   DBUG_ASSERT(fixed == 1);
+  null_value= 0;
   if (exec())
   {
     reset();
@@ -625,6 +626,7 @@
 longlong Item_in_subselect::val_int()
 {
   DBUG_ASSERT(fixed == 1);
+  null_value= 0;
   if (exec())
   {
     reset();
@@ -645,6 +647,7 @@
   */
   DBUG_ASSERT(0);
   DBUG_ASSERT(fixed == 1);
+  null_value= 0;
   if (exec())
   {
     reset();