MDEV-22764 Crash with a stored aggregate function returning INET6

Item_sum_sp did not override val_native(). So the reported script
crashed in the default implementation in Item::val_native() on DBUG_ASSERT().

Implementing a correct Item_sum_sp::val_native().

plugin/type_inet/mysql-test/type_inet/type_inet6.result

@@ -1986,3 +1986,38 @@ ERROR HY000: Illegal parameter data type inet6 for operation 'extract(day)'
 DROP TABLE t1;
 SELECT EXTRACT(DAY FROM CAST('::' AS INET6));
 ERROR HY000: Illegal parameter data type inet6 for operation 'extract(day)'
+#
+# MDEV-22764 Crash with a stored aggregate function returning INET6
+#
+CREATE OR REPLACE AGGREGATE FUNCTION aggregate_min_inet6(x INET6) RETURNS INET6
+BEGIN
+DECLARE res INET6 DEFAULT NULL;
+DECLARE CONTINUE HANDLER FOR NOT FOUND
+RETURN res;
+LOOP
+FETCH GROUP NEXT ROW;
+IF (res IS NULL) OR (res > x) THEN
+SET res= x;
+END IF;
+END LOOP;
+END;
+$$
+CREATE OR REPLACE TABLE t1 (name CHAR(30), val INET6);
+INSERT INTO t1 VALUES ('a', '::05');
+INSERT INTO t1 VALUES ('a', '::03');
+INSERT INTO t1 VALUES ('b', '::01');
+INSERT INTO t1 VALUES ('b', '::02');
+INSERT INTO t1 VALUES ('b', '::05');
+SELECT name, aggregate_min_inet6(val) pc FROM t1 GROUP BY name;
+name	pc
+a	::3
+b	::1
+CREATE OR REPLACE TABLE t2 (name CHAR(30), val INET6);
+INSERT INTO t2 SELECT name, aggregate_min_inet6(val) pc FROM t1 GROUP BY name;
+SELECT * FROM t2;
+name	val
+a	::3
+b	::1
+DROP TABLE t2;
+DROP TABLE t1;
+DROP FUNCTION aggregate_min_inet6;

plugin/type_inet/mysql-test/type_inet/type_inet6.test

@@ -1457,3 +1457,40 @@ SELECT EXTRACT(DAY FROM a) FROM t1;
 DROP TABLE t1;
 --error ER_ILLEGAL_PARAMETER_DATA_TYPE_FOR_OPERATION
 SELECT EXTRACT(DAY FROM CAST('::' AS INET6));
+
+
+--echo #
+--echo # MDEV-22764 Crash with a stored aggregate function returning INET6
+--echo #
+
+DELIMITER $$;
+CREATE OR REPLACE AGGREGATE FUNCTION aggregate_min_inet6(x INET6) RETURNS INET6
+BEGIN
+  DECLARE res INET6 DEFAULT NULL;
+  DECLARE CONTINUE HANDLER FOR NOT FOUND
+    RETURN res;
+  LOOP
+    FETCH GROUP NEXT ROW;
+    IF (res IS NULL) OR (res > x) THEN
+      SET res= x;
+    END IF;
+  END LOOP;
+END;
+$$
+DELIMITER ;$$
+
+CREATE OR REPLACE TABLE t1 (name CHAR(30), val INET6);
+INSERT INTO t1 VALUES ('a', '::05');
+INSERT INTO t1 VALUES ('a', '::03');
+INSERT INTO t1 VALUES ('b', '::01');
+INSERT INTO t1 VALUES ('b', '::02');
+INSERT INTO t1 VALUES ('b', '::05');
+SELECT name, aggregate_min_inet6(val) pc FROM t1 GROUP BY name;
+
+CREATE OR REPLACE TABLE t2 (name CHAR(30), val INET6);
+INSERT INTO t2 SELECT name, aggregate_min_inet6(val) pc FROM t1 GROUP BY name;
+SELECT * FROM t2;
+DROP TABLE t2;
+
+DROP TABLE t1;
+DROP FUNCTION aggregate_min_inet6;

sql/item_sum.h

@@ -1407,6 +1407,11 @@ class Item_sum_sp :public Item_sum,
     return sp_result_field->val_decimal(dec_buf);
   }
 
+  bool val_native(THD *thd, Native *to)
+  {
+    return null_value= execute() || sp_result_field->val_native(to);
+  }
+
   String *val_str(String *str)
   {
     String buf;