/* Test program for ungetc/fseekpos interaction.

   Copyright (C) 2004-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   Contributed by Jakub Jelinek <jakub@redhat.com>, 2004.

   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 <stdio.h>

static void do_prepare (void);

#define PREPARE(argc, argv) do_prepare ()

static int do_test (void);

#define TEST_FUNCTION do_test ()

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

static const char pattern[] = "abcdefghijklmnopqrstuvwxyz";

static char *temp_file;

static void

do_prepare (void)

{

  int fd = create_temp_file ("bug-ungetc.", &temp_file);

  if (fd == -1)

    {

      printf ("cannot create temporary file: %m\n");

      exit (1);

    }

  write (fd, pattern, sizeof (pattern) - 1);

  close (fd);

}

#define TEST_POS 5

static int

do_one_test (int mode)

{

  FILE *f = fopen (temp_file, "r");

  if (f == NULL)

    {

      printf ("%d: could not open temporary file: %m\n", mode);

      return 1;

    }

  int i;

  for (i = 0; i < TEST_POS; ++i)

    getc (f);

  fpos_t p;

  if (fgetpos (f, &p) != 0)

    {

      printf ("%d: fgetpos failed: %m\n", mode);

      return 1;

    }

  if (mode)

    {

      if (fseek (f, 0, SEEK_SET) != 0)

        {

          printf ("%d: fseek failed: %m\n", mode);

          return 1;

        }

      for (i = 0; i < TEST_POS - (mode >= 2); ++i)

        getc (f);

    }

  if (mode != 2 && ungetc ('X', f) != 'X')

    {

      printf ("%d: ungetc failed\n", mode);

      return 1;

    }

  if (mode == 3 && getc (f) != 'X')

    {

      printf ("%d: getc after ungetc did not return X\n", mode);

      return 1;

    }

  if (fsetpos (f, &p) != 0)

    {

      printf ("%d: fsetpos failed: %m\n", mode);

      return 1;

    }

  if (getc (f) != pattern[TEST_POS])

    {

      printf ("%d: getc did not return %c\n", mode, pattern[TEST_POS]);

      return 1;

    }

  fclose (f);

  return 0;

}

static int

do_test (void)

{

  int mode, ret = 0;

  for (mode = 0; mode <= 4; mode++)

    ret |= do_one_test (mode);

  return ret;

}