From: Steven Jenkins <steven.jenkins@...>
Date: 2005-02-24T03:14:21+09:00
Subject: Re: Strange argc check in stable snapshot

Berger, Daniel wrote:
>>-----Original Message-----
>>From: Steven Jenkins [mailto:steven.jenkins@ieee.org] 
>>Maybe a good idea nonetheless. It might catch a bug someday. Nothing 
>>*guarantees* that argc is nonnegative, not even for main().
> 
> I'll pledge $100 to RubyCentral immediately if someone can actually
> demonstrate how this might occur.
> 
> And no, assigning a negative value to argc directly doesn't count. :-P

int main(int argc, char *argv[])
{
     if (argc < 0)
         return 0;
     else
         main(-1, 0);
}

This is perfectly legal C. There's nothing special about main() except 
that the loader uses it as the entry point. Any other function can call 
it, including itself.

The argc in question is nonnegative by convention only. Someone could 
just make a mistake and call it with the wrong argument.

Steve