Thread: Re: [GENERAL] division by zero

Tom Lane wrote:
>
> I checked into this, and indeed OS X 10.2 is behaving funny: integer
> divide by zero doesn't raise any signal, it just returns a bogus
answer.
> They're within their rights to do so according to the ANSI C spec
> (wherein division by zero is stated to have undefined behavior).
> But since other BSD-derived Unixen all seem to raise SIGFPE, I can't
> help wondering if this shouldn't be considered a bug.

FWIW, this also is a problem with some of the windows ports.  For
example, 'select 0/0' is unpredictable and can cause the server to gpf
and restart.  This does not include the SRA port, because I don't have
it.

Merlin

Merlin Moncure wrote:
> Tom Lane wrote:
> > 
> > I checked into this, and indeed OS X 10.2 is behaving funny: integer
> > divide by zero doesn't raise any signal, it just returns a bogus
> answer.
> > They're within their rights to do so according to the ANSI C spec
> > (wherein division by zero is stated to have undefined behavior).
> > But since other BSD-derived Unixen all seem to raise SIGFPE, I can't
> > help wondering if this shouldn't be considered a bug.
> 
> FWIW, this also is a problem with some of the windows ports.  For
> example, 'select 0/0' is unpredictable and can cause the server to gpf
> and restart.  This does not include the SRA port, because I don't have
> it.

I just tested the SRA Win32 threaded port and both SELECT 1/0 and SELECT
0/0 crash the process.  I have reported this to Tatsuo.

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Bruce Momjian wrote:
<snip>
>>FWIW, this also is a problem with some of the windows ports.  For
>>example, 'select 0/0' is unpredictable and can cause the server to gpf
>>and restart.  This does not include the SRA port, because I don't have
>>it.
> 
> I just tested the SRA Win32 threaded port and both SELECT 1/0 and SELECT
> 0/0 crash the process.  I have reported this to Tatsuo.

Reported the issue to the Apple guys earlier on today, but haven't heard 
anything back from them yet.

Guess we'll have to wait a few days to find out where things are at in 
regards to MacOS X.

Regards and best wishes,

Justin Clift

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