MDEV-19164 Assertion `fixed' failed in Item_func_inet_aton::val_int

When pushing a condition from HAVING into WHERE the function
st_select_lex::pushdown_from_having_into_where() transforms column
references in the pushed condition then performs cleanup of
items of the condition and finally calls fix_fields() for the condition
items. The cleanup is performed by a call of the method walk() with
cleanup_processor as the first parameter. Unfortunately this sequence
of calls does not work if the condition contains cached items, because
fix_fields() cannot go through Item_cache items and this leaves
underlying items unfixed.
The solution of this problem used in this patch is just does not allow
to process Item_cache objects when performing cleanup of the pushed
condition. In order to let the traversal procedure walk() not to process
Item_cache objects the third parameter of the used call of walk()
is set to a fictitious pointer (void *) 1. And Item_cache::walk() is
changed to prevent any action when it gets such value as the third
parameter.

1 files changed, 30 insertions, 0 deletions

diff --git a/mysql-test/main/having_cond_pushdown.test b/mysql-test/main/having_cond_pushdown.test
index 257e5cb4875..5088dad734d 100644
--- a/mysql-test/main/having_cond_pushdown.test
+++ b/mysql-test/main/having_cond_pushdown.test
@@ -1340,3 +1340,33 @@ HAVING (v1.pk = 1);
 
 DROP TABLE t1,t2,tmp1;
 DROP VIEW v1;
+
+--echo #
+--echo # MDEV-19164: pushdown of condition with cached items
+--echo #
+
+create table t1 (d1 date);
+insert into t1 values (null),('1971-03-06'),('1993-06-05'),('1998-07-08');
+
+let $q1=
+select d1 from t1
+  group by d1
+    having d1 between (inet_aton('1978-04-27')) and '2018-08-26';
+
+eval $q1;
+eval explain extended $q1;
+eval explain format=json $q1;
+
+delete from t1;
+insert into t1 values ('2018-01-15'),('2018-02-20');
+
+let $q2=
+select d1 from t1
+  group by d1
+    having d1 not between 0 AND exp(0);
+
+eval $q2;
+eval explain extended $q2;
+eval explain format=json $q2;
+
+drop table t1;