Backport into build-201003230706-5.1.43sp1

> ------------------------------------------------------------
> revno: 3333.1.31
> revision-id: joro@sun.com-20091223104518-o29t0i3thgs7wgm1
> parent: sergey.glukhov@sun.com-20100205093946-bx1hsljxlm12h7uf
> committer: Georgi Kodinov <joro@sun.com>
> branch nick: B39022-5.1-bugteam
> timestamp: Wed 2009-12-23 12:45:18 +0200
> message:
>   Bug #39022: Mysql randomly crashing in lock_sec_rec_cons_read_sees
>   
>   flush_cached_records() was not correctly checking for errors after calling
>   Item::val_xxx() methods. The expressions may contain subqueries
>   or stored procedures that cause errors that should stop the statement.
>   Fixed by correctly checking for errors and propagating them up the call stack.

> ------------------------------------------------------------
> revno: 3358
> revision-id: sergey.glukhov@sun.com-20100226113925-mxwn1hfxe3l8khc4
> parent: gshchepa@mysql.com-20100225191311-1x71dkk0h5e1alvx
> committer: Sergey Glukhov <Sergey.Glukhov@sun.com>
> branch nick: mysql-5.1-bugteam
> timestamp: Fri 2010-02-26 15:39:25 +0400
> message:
>   Bug#50995 Having clause on subquery result produces incorrect results.
>   The problem is that cond->fix_fields(thd, 0) breaks
>   condition(cuts off 'having'). The reason of that is
>   that NULL valued Item pointer is present in the
>   middle of Item list and it breaks the Item processing
>   loop.

mysql-test/r/having.result

@@ -430,4 +430,24 @@ SELECT b, COUNT(DISTINCT a) FROM t1 GROUP BY b HAVING b is NULL;
 b	COUNT(DISTINCT a)
 NULL	1
 DROP TABLE t1;
+#
+# Bug#50995 Having clause on subquery result produces incorrect results.
+#
+CREATE TABLE t1
+(
+id1 INT,
+id2 INT NOT NULL,
+INDEX id1(id2)
+);
+INSERT INTO t1 SET id1=1, id2=1;
+INSERT INTO t1 SET id1=2, id2=1;
+INSERT INTO t1 SET id1=3, id2=1;
+SELECT t1.id1,
+(SELECT 0 FROM DUAL
+WHERE t1.id1=t1.id1) AS amount FROM t1
+WHERE t1.id2 = 1
+HAVING amount > 0
+ORDER BY t1.id1;
+id1	amount
+DROP TABLE t1;
 End of 5.0 tests

mysql-test/t/having.test

@@ -442,4 +442,30 @@ INSERT INTO t1 VALUES (1, 1), (2,2), (3, NULL);
 SELECT b, COUNT(DISTINCT a) FROM t1 GROUP BY b HAVING b is NULL;
 DROP TABLE t1;
 
+
+--echo #
+--echo # Bug#50995 Having clause on subquery result produces incorrect results.
+--echo #
+
+CREATE TABLE t1
+(
+ id1 INT,
+ id2 INT NOT NULL,
+ INDEX id1(id2)
+);
+
+INSERT INTO t1 SET id1=1, id2=1;
+INSERT INTO t1 SET id1=2, id2=1;
+INSERT INTO t1 SET id1=3, id2=1;
+
+SELECT t1.id1,
+(SELECT 0 FROM DUAL
+ WHERE t1.id1=t1.id1) AS amount FROM t1
+WHERE t1.id2 = 1
+HAVING amount > 0
+ORDER BY t1.id1;
+
+DROP TABLE t1;
+
+
 --echo End of 5.0 tests

sql/item_cmpfunc.h

@@ -1474,9 +1474,21 @@ public:
   Item_cond(THD *thd, Item_cond *item);
   Item_cond(List<Item> &nlist)
     :Item_bool_func(), list(nlist), abort_on_null(0) {}
-  bool add(Item *item) { return list.push_back(item); }
-  bool add_at_head(Item *item) { return list.push_front(item); }
-  void add_at_head(List<Item> *nlist) { list.prepand(nlist); }
+  bool add(Item *item)
+  {
+    DBUG_ASSERT(item);
+    return list.push_back(item);
+  }
+  bool add_at_head(Item *item)
+  {
+    DBUG_ASSERT(item);
+    return list.push_front(item);
+  }
+  void add_at_head(List<Item> *nlist)
+  {
+    DBUG_ASSERT(nlist->elements);
+    list.prepand(nlist);
+  }
   bool fix_fields(THD *, Item **ref);
 
   enum Type type() const { return COND_ITEM; }

sql/sql_select.cc

@@ -8176,7 +8176,8 @@ static Item *eliminate_item_equal(COND *cond, COND_EQUAL *upper_levels,
   else
   {
     DBUG_ASSERT(cond->type() == Item::COND_ITEM);
-    ((Item_cond *) cond)->add_at_head(&eq_list);
+    if (eq_list.elements)
+      ((Item_cond *) cond)->add_at_head(&eq_list);
   }
 
   cond->quick_fix_field();
@@ -15613,7 +15614,7 @@ static bool add_ref_to_table_cond(THD *thd, JOIN_TAB *join_tab)
 
   Item_cond_and *cond=new Item_cond_and();
   TABLE *table=join_tab->table;
-  int error;
+  int error= 0;
   if (!cond)
     DBUG_RETURN(TRUE);
 
@@ -15631,7 +15632,8 @@ static bool add_ref_to_table_cond(THD *thd, JOIN_TAB *join_tab)
     cond->fix_fields(thd, (Item**)&cond);
   if (join_tab->select)
   {
-    error=(int) cond->add(join_tab->select->cond);
+    if (join_tab->select->cond)
+      error=(int) cond->add(join_tab->select->cond);
     join_tab->select_cond=join_tab->select->cond=cond;
   }
   else if ((join_tab->select= make_select(join_tab->table, 0, 0, cond, 0,