MDEV-19186: Assertion `field->table == table' failed in create_tmp_table

Temporary table is defined with the view field in HAVING.
Item_direct_view_ref for this field is dropped and that causes error.

To fix it Item_direct_view_ref::remove_item_direct_ref() is added.

mysql-test/main/having_cond_pushdown.result

@@ -4641,3 +4641,19 @@ pk
 3
 DROP TABLE t1;
 DROP VIEW v1;
+#
+# MDEV-19186: temporary table defined with view field in HAVING
+#
+CREATE TABLE t1 (pk INT, x VARCHAR(10));
+INSERT INTO t1 VALUES  (1,'y'),(2,'s'),(3,'aaa');
+CREATE VIEW v1 AS SELECT * FROM t1;
+CREATE TABLE t2 (pk INT, x VARCHAR(10));
+INSERT INTO t2 VALUES (1,'aa'),(2,'t'),(3,'bb');
+CREATE TABLE tmp1
+SELECT v1.pk
+FROM t2,v1
+WHERE v1.x = t2.x
+GROUP BY v1.pk
+HAVING (v1.pk = 1);
+DROP TABLE t1,t2,tmp1;
+DROP VIEW v1;

mysql-test/main/having_cond_pushdown.test

@@ -1318,3 +1318,25 @@ HAVING (1 NOT IN (SELECT COUNT(t1.c1) FROM (v1, t1)));
 
 DROP TABLE t1;
 DROP VIEW v1;
+
+
+--echo #
+--echo # MDEV-19186: temporary table defined with view field in HAVING
+--echo #
+
+CREATE TABLE t1 (pk INT, x VARCHAR(10));
+INSERT INTO t1 VALUES  (1,'y'),(2,'s'),(3,'aaa');
+CREATE VIEW v1 AS SELECT * FROM t1;
+
+CREATE TABLE t2 (pk INT, x VARCHAR(10));
+INSERT INTO t2 VALUES (1,'aa'),(2,'t'),(3,'bb');
+
+CREATE TABLE tmp1
+SELECT v1.pk
+FROM t2,v1
+WHERE v1.x = t2.x
+GROUP BY v1.pk
+HAVING (v1.pk = 1);
+
+DROP TABLE t1,t2,tmp1;
+DROP VIEW v1;

sql/item.h

@@ -5733,6 +5733,7 @@ class Item_direct_view_ref :public Item_direct_ref
   { return get_item_copy<Item_direct_view_ref>(thd, this); }
   Item *field_transformer_for_having_pushdown(THD *thd, uchar *arg)
   { return this; }
+  Item *remove_item_direct_ref() { return this; }
 };