Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!apple!alexr@apple.com
From: alexr@apple.com (Alexander M. Rosenberg)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Toolbox Patching
Message-ID: <13741@goofy.Apple.COM>
Date: 30 May 91 01:26:07 GMT
References: <1991May28.163618.8353@crash.cts.com> <13613@dog.ee.lbl.gov> <772@goblin.ntg.com>
Sender: usenet@Apple.COM
Organization: Hackers Anonymous
Lines: 36


I'm gonna get shot for this, but...

In article <772@goblin.ntg.com>, dplatt@ntg.com (Dave Platt) writes:
> 
> In article <13613@dog.ee.lbl.gov> osborn@ux1.lbl.gov (James R Osborn) writes:
> 
> >Just what exactly is the preferred method for applying a
> >tail patch to a Toolbox routine?
> 
> There is NO preferred method for tail-patching.  It should not be done.
> 

This isn't really true. Rule #627 about tail patching:

If your code _only_ works under System 7.0 anyway (and the patch installation
code aborts if you aren't under 7.0), then _most_ tail patches are safe.

Before you try to tail patch something, watch what SetTrapAddress does. You
may notice that it preserves "come-from" patches (the kind you don't want to
tail patch) for _most_ traps.

Again:

1.) Check before you try.

2.) Only 7.0.

3.) Not official (read: may change).

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