Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!pasteur!ucbvax!hoptoad!tim
From: tim@hoptoad.uucp (Tim Maroney)
Newsgroups: comp.sys.mac.programmer
Subject: Re: What is OpenRFPerm doing?!?
Keywords: resource corrupt OpenRFPerm
Message-ID: <7087@hoptoad.uucp>
Date: 25 Apr 89 18:39:28 GMT
References: <1146@uvm-gen.UUCP> <7017@hoptoad.uucp> <1152@uvm-gen.UUCP>
Reply-To: tim@hoptoad.UUCP (Tim Maroney)
Organization: Eclectic Software, San Francisco
Lines: 46

In article <1152@uvm-gen.UUCP> chaffee@uvm-gen.UUCP (Alex D. Chaffee) writes:
>Tim, your intuition seems to be correct.  Although I haven't _quite_
>finished debugging the whole program, it is obvious that the problem lies
>with certain, apparently corrupt, resource files.

Well, it's not certain yet (see below).

>(For those of you who've just joined us:  When I opened the resource fork of
> a file with OpenRFPerm directly following an SFGetFile, my resource map
> got trashed, as evidenced by Alerts appearing off-screen and so forth.)
>
>I now have two questions:
>
>1)	ResEdit opens these files (there are two) fine, and the FKEYs within
>	them work fine when installed into the system.  What can be special
>	about them?

I don't know how much special checking ResEdit does.  (Jon?)  If I
wonder about the correctness of a file, I go into MPW and run the
RezDet tool on it.  This picks up and reports on a wide variety of
resource file problems.  ResEdit bypasses the Resource Manager and
handles the resource file format directly, so it is possible that
there could be an error that wouldn't make ResEdit choke but would
make the RM freak out.  I have to say it seems a bit unlikely.

>2)	How can I programmatically detect and/or correct this user-nasty
>	situation?  Or any similar situation where the Resource Manager gets
>	confused...  Is there an error-reporting function or global?  I seem
>	to remember catching the end of a related thread on the net a week or
>	two ago.

In practice, I don't think any developers actually check their resource
files except for the few that bypass the resource manager completely.
Remember, though, the real problem is that if you let users open any
resource files that aren't owned by you, you can't guarantee that its
resources won't conflict with yours, and you shouldn't keep it in the
resource search path except during the rare times when you're
extracting information from it and changing information in it.  I still
tend to suspect that you may have some such conflict situation here.
Could you describe in a bit more detail why you are opening the
resource files?
-- 
Tim Maroney, Consultant, Eclectic Software, sun!hoptoad!tim
"The above opinions and suggestions have absolutely nothing to do with
 the little, fat man putting crisp, $100 bills in my pocket."
    -- Alan Vymetalik