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Bug#50995 Having clause on subquery result produces incorrect results.

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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:
  test case
mysql-test/t/having.test:
  test case
sql/item_cmpfunc.h:
  added ASSERT to make sure that we do not add NULL valued Item pointer
sql/sql_select.cc:
  skip adding an item to condition if Item pointer is NULL.
  skip adding a list to condition if this list is empty.
This commit is contained in:
Sergey Glukhov
2010-02-26 15:39:25 +04:00
parent 936ed6ca86
commit 9245ed4a12
4 changed files with 66 additions and 6 deletions
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8
sql/sql_select.cc
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@@ -8200,7 +8200,8 @@ 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();
@@ -15657,7 +15658,7 @@ 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);
@@ -15675,7 +15676,8 @@ 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,