Cypher: only first case seems to be considered in subroutine when using UNION #3772

# returns no results (wrong, neo4j returns success2 = 1)
WITH [] as toRemove
CALL {
  WITH toRemove WITH toRemove
  WHERE SIZE(toRemove) > 0
  RETURN 2 AS success2
  UNION
  WITH toRemove WITH toRemove
  WHERE SIZE(toRemove) = 0
  RETURN 1 AS success2
}
RETURN success2

# returns success2 = 2 (correct)
WITH ["a"] as toRemove
CALL {
  WITH toRemove WITH toRemove
  WHERE SIZE(toRemove) > 0
  RETURN 2 AS success2
  UNION
  WITH toRemove WITH toRemove
  WHERE SIZE(toRemove) = 0
  RETURN 1 AS success2
}
RETURN success2