From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <glibc-bugs-return-5738-listarch-glibc-bugs=sources.redhat.com@sourceware.org>
Received: (qmail 10926 invoked by alias); 6 Dec 2006 01:54:26 -0000
Received: (qmail 8848 invoked by uid 48); 6 Dec 2006 01:54:16 -0000
Date: Wed, 06 Dec 2006 01:54:00 -0000
From: "jsm28 at gcc dot gnu dot org" <sourceware-bugzilla@sourceware.org>
To: glibc-bugs@sources.redhat.com
Message-ID: <20061206015415.3664.jsm28@gcc.gnu.org>
Reply-To: sourceware-bugzilla@sourceware.org
Subject: [Bug libc/3664] New: strtod handling of all-zeros numbers broken
X-Bugzilla-Reason: CC
Mailing-List: contact glibc-bugs-help@sourceware.org; run by ezmlm
Precedence: bulk
List-Id: <glibc-bugs.sourceware.org>
List-Subscribe: <mailto:glibc-bugs-subscribe@sourceware.org>
List-Post: <mailto:glibc-bugs@sourceware.org>
List-Help: <mailto:glibc-bugs-help@sourceware.org>, <http://sourceware.org/lists.html#faqs>
Sender: glibc-bugs-owner@sourceware.org
X-SW-Source: 2006-12/txt/msg00010.txt.bz2

strtod_l.c contains a conditional which is never going to pass because it
requires both base == 16 and base != 16.

  if ((c < L_('0') || c > L_('9'))
      && (base == 16 && (c < (CHAR_TYPE) TOLOWER (L_('a'))
                         || c > (CHAR_TYPE) TOLOWER (L_('f'))))
#ifdef USE_WIDE_CHAR
      && c != (wint_t) decimal
#else
      && ({ for (cnt = 0; decimal[cnt] != '\0'; ++cnt)
              if (decimal[cnt] != cp[cnt])
                break;
            decimal[cnt] != '\0'; })
#endif
      && (base == 16 && (cp == start_of_digits
                         || (CHAR_TYPE) TOLOWER (c) != L_('p')))
      && (base != 16 && (CHAR_TYPE) TOLOWER (c) != L_('e')))

I believe the fix is to change "base == 16 &&" to "base != 16 ||" in both
places, "base != 16 &&" to "base == 16 ||", "c < (CHAR_TYPE) TOLOWER (L_('a'))"
to "(CHAR_TYPE) TOLOWER (c) < L_('a')" and likewise for 'f'.

The following test shows that this causes an actual bug.

#include <stdlib.h>
int
main(void)
{
  const char *s = "0x";
  char *ep;
  double r = strtod(s, &ep);
  if (r != 0)
    abort();
  if (ep != s + 1)
    abort();
  exit(0);
}

-- 
           Summary: strtod handling of all-zeros numbers broken
           Product: glibc
           Version: 2.4
            Status: NEW
          Severity: normal
          Priority: P2
         Component: libc
        AssignedTo: drepper at redhat dot com
        ReportedBy: jsm28 at gcc dot gnu dot org
                CC: glibc-bugs at sources dot redhat dot com


http://sourceware.org/bugzilla/show_bug.cgi?id=3664

------- You are receiving this mail because: -------
You are on the CC list for the bug, or are watching someone who is.