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From: Charles Sandmann <sandmann AT clio DOT rice DOT edu>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: fsdb v2 and cwsdpmi bug?
Date: Mon, 14 Aug 1995 00:14:23 CDT
Organization: Rice University, Houston, Texas
Lines: 15
References: <DD4DyI DOT Eqq AT jade DOT mv DOT net> <302b8cd1 DOT sandmann AT clio DOT rice DOT edu> <40hic7$6mq AT kendaco DOT telebyte DOT com>
Reply-To: sandmann AT clio DOT rice DOT edu
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To: djgpp AT sun DOT soe DOT clarkson DOT edu
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> : > Then I try to run fsdb with cwsdpmi b5 I get the following error as soon as
> : > I hit f8 (step) or f9 (run):
> : > Page fault at eip=00011926
>   I guess I'll go look for an older CWSDPMI for now...

The problem isn't CWSDPMI, it's FSDB accessing a NULL pointer.  The older 
version just didn't allow this check to be performed.

I disassebled the failing line, and saw:
  cmp [ecx],al
And since ecx == 0 in the register list, NULL pointer.  Good guess, eh?

Anyway, FSDB needs to be fixed.  For the meantime you can re-compile it
setting the crt0 flag which allows null pointers to be ignored instead of
caught.