/* Copyright (C) 2003-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.  */

#include <errno.h>

#include <stdio.h>

#include <unistd.h>

/* Test that nice() does not incorrectly return 0.  */

static int

do_test (void)

{

  int ret;

  const int incr = 10;

  int old;

  /* Discover current nice value.  */

  errno = 0;

  old = nice (0);

  if (old == -1 && errno != 0)

    {

      printf ("break: nice(%d) return: %d, %m\n", 0, old);

      return 1;

    }

  /* Nice ourselves up.  */

  errno = 0;

  ret = nice (incr);

  if (ret == -1 && errno != 0)

    {

      printf ("break: nice(%d) return: %d, %m\n", incr, ret);

      return 1;

    }

  /* Check for return value being zero when it shouldn't.  Cannot simply

     check for expected value since nice values are capped at 2^n-1.

     But we assume that we didn't start at the cap and so should have

     increased some.  */

  if (ret <= old)

    {

      printf ("FAIL: retval (%d) of nice(%d) != %d\n", ret, incr, old + incr);

      return 1;

    }

  /* BZ #18086. Make sure we don't reset errno.  */

  errno = EBADF;

  nice (0);

  if (errno != EBADF)

    {

      printf ("FAIL: errno = %i, but wanted EBADF (%i)\n", errno, EBADF);

      return 1;

    }

  printf ("PASS: nice(%d) from %d return: %d\n", incr, old, ret);

  return 0;

}

#define TEST_FUNCTION do_test ()

#include "../test-skeleton.c"