Previous issue Thread #968242

Bug/Issue : 29 of 49

TITLE: BUG : aritmetic operators fire error with nulls data

VERSION: 09.00.0000.1720 and previous

EXPECTED: return NULL without check the data type of variables

OBSERVED:
- logical expressions don't check type of elements
- change sign of a logical null return null
- +-*/^% fire a error with nulls

REPRO:

  x=null
  * Expected NULL Observed NULL
  ? NULL = x
  * Expected NULL Observed NULL
  ? NULL + x
    * Expected NULL Observed NULL
  ? -X        && - (Logical null)
  * Expected NULL Observed Error => Bug
   ? 0-X   
  
  y=3
  y=null
  
  * Expected NULL Observed NULL
  ? Y= X && (numeric null) = (Logical null)
  * Expected NULL Observed NULL
  ? Y AND X  && (Logical null) AND (numeric null)
  * Expected NULL Observed Error => Bug
  ? y - X  && (numeric null) - (Logical null)

Effect :
If you write a polimorphic method with a variant parameter,
the inner code have to cast the null value before to use it.