NULL operand ignored in vtable mode when querying view

With the example below, columnstore return a number instead of NULL in the addition when there is a if in the view and using vtable=0 gives NULL.

use test;
create table test_bug(a float default null, b float default null) engine=Columnstore;
insert into test.test_bug values (rand(),rand()),(rand(),rand()),(rand(),rand()),(rand(),rand());
create or replace view test_bug_view (a,b,c) as select a,b,(abs(a*2.6+b*38.7))*1.16+if(a>0.5,a,1.0 -(a*0.1)) as c from test.test_bug;
set infinidb_vtable_mode=1;
select c+NULL as t,c from test.test_bug_view;
set infinidb_vtable_mode=0;
select c+NULL as t,c from test.test_bug_view;