BUG #1329: Bug in IF-ELSEIF-ELSE construct

The following bug has been logged online:

Bug reference: 1329
Logged by: Rico Wind

Email address: rw(at)rico-wind(dot)dk

PostgreSQL version: 8.0 Beta

Operating system: Windows XP, SP2

Description: Bug in IF-ELSEIF-ELSE construct

Details:

Beta 1.
The following always returns 4:

IF from_date_param=period_begin AND until_date_param=period_end
THEN
return 1;
ELSEIF from_date_param=period_begin
THEN
return 2;
ELSEIF until_date_param=period_end
THEN
return 3;
ELSE
return 4;
END IF;

Whereas the following returns the right answer(not 4 each time). They should
be the same.
IF from_date_param=period_begin AND until_date_param=period_end
THEN
return 1;
ELSE
IF from_date_param = period_begin
THEN
return 2;
END IF;

IF until_date_param=period_end
THEN
return 3;
END IF;
END IF;
RETURN 4;