Path: utzoo!attcan!uunet!husc6!bloom-beacon!ZERMATT.LCS.MIT.EDU!RWS
From: RWS@ZERMATT.LCS.MIT.EDU (Robert Scheifler)
Newsgroups: comp.windows.x
Subject: MALLOC_0_RETURNS_NULL
Message-ID: <19880617120851.3.RWS@KILLINGTON.LCS.MIT.EDU>
Date: 17 Jun 88 12:08:00 GMT
References: <94.8806170546@latlog.co.uk>
Sender: daemon@bloom-beacon.MIT.EDU
Organization: The Internet
Lines: 26


    Date: Fri, 17 Jun 88 06:46:55 -0100
    From: mcvax!latlog!PAYNE@uunet.uu.net

    Is there any reason why this exists and why it is not defined?

It exists because not all systems work the same way for malloc(0).
Handling NULL incurs an expense on all mallocs, and since V11R2 has
primarily been installed on BSD based systems rather than SVID compliant
systems, it was turned off by default.  (Also, it was put in at the last
minute before R1 shipped, and hadn't been tested, and was mostly
forgotten about since.)

    Having spent two days tracking this down it is very frustrating to find
    that this non-standard behaviour is the reason.

Unfortunately, there is more than one "standard" here.  You won't find
this behavior documented in most BSD based documentation.

    Is this feature documented anywhere?

Probably not.

    If it is not (and I couldn't find it) it certainly ought to be?

Yup.