# ===========================================================================
#        http://www.nongnu.org/autoconf-archive/ax_snprintf_oflow.html
# ===========================================================================
#
# SYNOPSIS
#
#   ax_snprintf_oflow
#
# DESCRIPTION
#
#   Checks whether snprintf ignores the value of n or not and defines
#   HAVE_SNPRINTF_BUG if it does.
#
# LICENSE
#
#   Copyright (c) 2008 Duncan Simpson <dps@simpson.demon.co.uk>
#
#   Copying and distribution of this file, with or without modification, are
#   permitted in any medium without royalty provided the copyright notice
#   and this notice are preserved.

AC_DEFUN([ax_snprintf_oflow],
[AC_MSG_CHECKING(whether snprintf ignores n)
AC_CACHE_VAL(ax_cv_snprintf_bug,
[AC_TRY_RUN(
changequote(<<, >>)dnl
<<#include <stdio.h>

#ifndef HAVE_SNPRINTF
#ifdef HAVE_VSNPRINTF
#include "vsnprintf.h"
#else /* not HAVE_VSNPRINTF */
#include "vsnprintf.c"
#endif /* HAVE_VSNPRINTF */
#endif /* HAVE_SNPRINTF */

int main(void)
{
char ovbuf[7];
int i;
for (i=0; i<7; i++) ovbuf[i]='x';
snprintf(ovbuf, 4,"foo%s", "bar");
if (ovbuf[5]!='x') exit(1);
snprintf(ovbuf, 4,"foo%d", 666);
if (ovbuf[5]!='x') exit(1);
exit(0);
} >>
changequote([, ]), ax_cv_snprintf_bug=0, ax_cv_snprintf_bug=1,
ax_cv_snprintf_bug=2)])
if test $ax_cv_snprintf_bug -eq 0; then
  AC_MSG_RESULT([no, snprintf is ok])
else if test $ax_cv_snprintf_bug -eq 1; then
  AC_MSG_RESULT([yes, snprintf is broken])
  AC_DEFINE(HAVE_SNPRINTF_BUG,1)
else
  AC_MSG_RESULT([unknown, assuming yes])
  AC_DEFINE(HAVE_SNPRINTF_BUG,1)
fi; fi])