Fixed the bug mdev-7599.

At some conditions the function opt_sum_query() can apply MIN/MAX
optimizations to to Item_sum objects of a select These optimizations
becomes invalid if this select is the subquery of an IN subquery
predicate that is converted to a EXISTS subquery. Thus in this case
the MIX/MAX optimizations that have been applied in opt_sum_query()
must be rolled back.
This bug appeared in 5.3 when the code for the cost base choice between
materialization and in-to-exists transformation of non-correlated
IN subqueries was introduced. Before this code in-to-exists
transformations were always performed before the call of opt_sum_query().

1 files changed, 9 insertions, 0 deletions

diff --git a/sql/opt_sum.cc b/sql/opt_sum.cc
index aa8b17a2c85..1a8c6be5f41 100644
--- a/sql/opt_sum.cc
+++ b/sql/opt_sum.cc
@@ -253,6 +253,8 @@ int opt_sum_query(THD *thd,
   int error= 0;
   DBUG_ENTER("opt_sum_query");
 
+  thd->lex->current_select->min_max_opt_list.empty();
+
   if (conds)
     where_tables= conds->used_tables();
 
@@ -444,7 +446,14 @@ int opt_sum_query(THD *thd,
           item_sum->aggregator_clear();
         }
         else
+        {
           item_sum->reset_and_add();
+          /*
+            Save a reference to the item for possible rollback
+            of the min/max optimizations for this select
+          */
+	  thd->lex->current_select->min_max_opt_list.push_back(item_sum);
+        }
         item_sum->make_const();
         recalc_const_item= 1;
         break;