Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!caen!kuhub.cc.ukans.edu!2fmlcalls
From: 2fmlcalls@kuhub.cc.ukans.edu
Newsgroups: comp.sys.mac.programmer
Subject: Re: Why won't ResError return the right message?
Message-ID: <1991May6.143630.30448@kuhub.cc.ukans.edu>
Date: 6 May 91 14:36:30 CDT
References: <1696@babcock.cerc.wvu.wvnet.edu>
Organization: University of Kansas Academic Computing Services
Lines: 25

> Even though GetResource couldn'thave found the resource (because
> it wasn't there), ResError returned a 0, indicating that nothing
> was wrong.  Needless to say, the first time I referred to the
> resource, I got a Bus Error exception, because I was following
> the invalid handle out into La-La Land.
> 
> Why didn't ResError tell me there was a problem?
> 
> --Kurisuto
> un020070@vaxa.wvnet.edu

I've seen it documented that ResError doesn't always return 0.  I think the
preferred method is to check the resource hanfter you read it in.  Check for
nil.  

if (myRes = nil) then ....

  or

if (myRes^=nil) then ...

I've never been clear which is more reliable, the handle or pointer.

john calhoun