Submitted by: Claudio Valderrama C. (robocop)

Assigned to: Claudio Valderrama C. (robocop)

SFID: 421263#⁠
Submitted By: robocop

The substr UDF that comes with FB returns NULL when
the final position is greater than the last position
in the input string argument. This causes any kind of
problems. Hence, two solutions have been provided:
- Fix substr so it will return NULL when provided with
NULL, but it will report the full string if the final
position of the slice is greater than the strig.
- Add substrlen that will have the argument most
people are used to: starting position plus length of
the slice instead of starting and final position.

The final solution will come when a substr function,
ANSI compliant, can implemented in the server's core
in the future.

C.