sum of col=value fails with Internal error: std::bad_typeid

I have a probleme with this patch https://jira.mariadb.org/browse/MCOL-301

The test is ok :
----------------------------------------------------

1. mysql 14:23:48 > create table t1 (a int) engine=columnstore;
   Query OK, 0 rows affected (0.08 sec)

1. mysql 14:24:18 > insert into t1 values (1),(1),(2),(2),(3),(3);
   Query OK, 6 rows affected (0.08 sec)
   Records: 6 Duplicates: 0 Warnings: 0

1. mysql 14:24:24 > select sum(1) from t1;
   --------

   sum(1)

   --------

   1

   --------
   1 row in set (0.03 sec)

1. mysql 14:24:37 > select sum((a=1)*(1=1)) from t1;
   ------------------

   sum((a=1)*(1=1))

   ------------------

   2

   ------------------
   1 row in set (0.01 sec)
   -----------------------------------------------------------------

But I am obliged to add *(1*1) . Too bad

1. mysql 14:25:02 > select sum(a=1) from t1;
   ERROR 1815 (HY000): Internal error: std::bad_typeid