Path: utzoo!utgpu!jarvis.csri.toronto.edu!clyde.concordia.ca!rutgers!mephisto!prism!cc100aa
From: cc100aa@prism.gatech.EDU (Ray Spalding)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Crash recovery under MultiFinder
Keywords: resume, system error, unexpectedly quit
Message-ID: <5718@hydra.gatech.EDU>
Date: 6 Feb 90 21:11:08 GMT
References: <4413@vanuata.cs.glasgow.ac.uk>
Reply-To: cc100aa@prism.gatech.EDU (Ray Spalding)
Organization: Georgia Institute of Technology
Lines: 40

In article <4413@vanuata.cs.glasgow.ac.uk> dunlop@cs.glasgow.ac.uk (Mark Dunlop) writes:
>[...] Is there any way to [...] tell the system 
>to give me the good ole System Error dialogue rather than the MultiFinder 
>getting its paws on it and mucking up any crash recovery? [...]

I asked a similar question a few months back, and the best answer I
got was to patch ExitToShell().  This seems to work well under both
Multi- and Unifinder.  But note that your patch gets control under
normal exit conditions as well as error conditions (unless you un-patch
before exiting).

The code I'm using (MPW C) looks like the following; perhaps someone
more familiar with patching could comment if there are any potential
problems with this code.

#include <Segload.h>
#include <Traps.h>
#include <OSUtils.h>
pascal void resume_proc();
long sysExit;
main() {
	/* ... */
	sysExit = NGetTrapAddress(_ExitToShell,ToolTrap);
	NSetTrapAddress((long)resume_proc,_ExitToShell,ToolTrap);
	/* ... */
}
pascal void resume_proc()
{
	if (sysExit) {
		NSetTrapAddress(sysExit,_ExitToShell,ToolTrap);
	}
	/* clean up my mess ... */
	ExitToShell();
}

-- 
Ray Spalding, Office of Computing Services
Georgia Institute of Technology, Atlanta Georgia, 30332-0275
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