MDEV-5113 Wrong result (extra row) and valgrind warnings in...

MDEV-5113 Wrong result (extra row) and valgrind warnings in Item_maxmin_subselect::any_value on 2nd execution of PS with SELECT subquery

When setting Item_func_not_all::test_sum_item or Item_func_not_all::test_sub_item,
reset the other one to NULL - they can never be set both. When a PS is reexecuted,
different executions might be optimized differently and a wrong test_su*_item
might stay set from the previous execution.

mysql-test/r/ps_max_subselect-5113.result

+CREATE TABLE t1 (b INT NOT NULL);
+INSERT INTO t1 VALUES (0),(8);
+PREPARE stmt FROM '
+ SELECT 1 FROM t1 AS o 
+   WHERE o.b >= ALL ( 
+     SELECT a2.b FROM t1 AS a1 LEFT JOIN t1 AS a2 ON ( a2.b = a1.b ) 
+     WHERE a1.b <= a2.b 
+  )
+';
+EXECUTE stmt;
+1
+1
+EXECUTE stmt;
+1
+1
+DROP TABLE t1;

mysql-test/t/ps_max_subselect-5113.test

+#
+# MDEV-5113 Wrong result (extra row) and valgrind warnings in Item_maxmin_subselect::any_value on 2nd execution of PS with SELECT subquery
+#
+
+CREATE TABLE t1 (b INT NOT NULL);
+INSERT INTO t1 VALUES (0),(8);
+
+PREPARE stmt FROM '
+ SELECT 1 FROM t1 AS o 
+   WHERE o.b >= ALL ( 
+     SELECT a2.b FROM t1 AS a1 LEFT JOIN t1 AS a2 ON ( a2.b = a1.b ) 
+     WHERE a1.b <= a2.b 
+  )
+';
+
+EXECUTE stmt;
+EXECUTE stmt;
+
+DROP TABLE t1;
+

sql/item_cmpfunc.h

@@ -508,8 +508,8 @@ class Item_func_not_all :public Item_func_not
   bool fix_fields(THD *thd, Item **ref)
     {return Item_func::fix_fields(thd, ref);}
   virtual void print(String *str, enum_query_type query_type);
-  void set_sum_test(Item_sum_hybrid *item) { test_sum_item= item; };
-  void set_sub_test(Item_maxmin_subselect *item) { test_sub_item= item; };
+  void set_sum_test(Item_sum_hybrid *item) { test_sum_item= item; test_sub_item= 0; };
+  void set_sub_test(Item_maxmin_subselect *item) { test_sub_item= item; test_sum_item= 0;};
   bool empty_underlying_subquery();
   Item *neg_transformer(THD *thd);
 };