Date: Sun, 15 Sep 2002 23:40:03 -0700 (PDT) From: Gregory Bond <gnb@itga.com.au> To: freebsd-bugs@FreeBSD.org Subject: Re: kern/42818: qsort can only sort up to 6 element for structure Message-ID: <200209160640.g8G6e35s073174@freefall.freebsd.org>
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The following reply was made to PR kern/42818; it has been noted by GNATS.
From: Gregory Bond <gnb@itga.com.au>
To: j_guojun@lbl.gov
Cc: FreeBSD-gnats-submit@FreeBSD.ORG
Subject: Re: kern/42818: qsort can only sort up to 6 element for structure
Date: Mon, 16 Sep 2002 16:30:13 +1000
The bug is in your program. To quote qsort(3):
The comparison function must return an integer less than, equal to, or
greater than zero if the first argument is considered to be respectively
less than, equal to, or greater than the second.
Your comparison function returns 0 or 1 only. Perhaps you are being confused
by the C++/STL comparison objects?
Modifying your comparison fn to the following makes it work:
int
smaller(const void *i1, const void *i2)
{
if (*(int*)i1 < *(int*)i2) return -1;
return *(int*)i1 > *(int*)i2;
}
The fact that your test program seems to work for these test cases on Solaris
and Linux is a simple coincidence, and depends on fine internal details of the
sort algorithm on those systems. There will probably be other cases where the
Linux/Solaris qsort() will also fail.
This PR can be closed.
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