[firebird-support] Bug?

[liviuslivius]

H,
 
FB2.5.3.26738
this query return 0
 
SELECT count(*) FROM RDB$DATABASE WHERE  ((CAST(NULL AS INTEGER) IS NULL AND 
CAST(123 AS INTEGER) IS NULL) OR
(CAST(NULL AS INTEGER)=1))
 
when i add "NOT" this query return also 0
 
SELECT count(*) FROM RDB$DATABASE WHERE NOT ((CAST(NULL AS INTEGER) IS NULL AND 
CAST(123 AS INTEGER) IS NULL) OR
(CAST(NULL AS INTEGER)=1))
 
 
is this a bug?
 
regards,
Karol Bieniaszewski