[Firebird-test] FB3: duplicate function arguments should not be allowed

[Robbert-Jan <rjm...@xs...>]

Hi, 
testing FB 3 (Windows, WI-T3.0.0.30566 Firebird 3.0 Alpha 1), I see that currently stored functions may have input arguments with the same name, like:

CREATE FUNCTION Test (X INTEGER, X INTEGER) /* argument X appears twice */
RETURNS INTEGER
AS
BEGIN
  RETURN X + 1;
END

I think this should not be allowed, like it is also not allowed for parameters of stored procedures.
I suggest to define a unique key on rdb$function_arguments for (rdb$function_name, rdb$argument_name); note rdb$argument_name is NULL for the return argument, but afaik this is okay for unique keys.

Kind regards, Robert