unexpected null values behavior in condensers

[Dimitar Misev]

The result of a condenser applied on an array with nulls can accidentally be a null in further operations.

E.g. (queries below):

testNull is an array of 5 elements, all 1, null value is 2.
add_cells(testNull[0:1]) is 2. add_cells(testNull[0:1]) + 1 is still 2.
The result of the condenser shouldn't be considered a null.

Queries to reproduce:

./rasql —user rasadmin —passwd rasadmin -q 'create collection testNull GreySet1'

./rasql —user rasadmin —passwd rasadmin -q 'insert into testNull values marray x in [0:4] values 1c'

./rasql —user rasadmin —passwd rasadmin -q 'update testNull set testNull assign null values [2:2]'

./rasql -q 'select add_cells(a[0:1]) from testNull a' —out string

./rasql -q 'select add_cells(a[0:1])+1 from testNull a' —out string