/* Test program for ungetc/ftell interaction bug.  */

#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[] = "12345";

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));

  close (fd);

}

static int

do_test (void)

{

  int i;

  FILE *f;

  char buf[10];

  long offset, diff;

  int result = 0;

  f = fopen (temp_file, "rw");

  rewind (f);

  for (i = 0; i < 3; i++)

    printf ("%c\n", getc (f));

  offset = ftell (f);

  printf ("offset = %ld\n", offset);

  if (ungetc ('4', f) != '4')

    {

      printf ("ungetc failed\n");

      abort ();

    }

  printf ("offset after ungetc = %ld\n", ftell (f));

  i = fread ((void *) buf, 4, (size_t) 1, f);

  printf ("read %d (%c), offset = %ld\n", i, buf[0], ftell (f));

  diff = ftell (f) - offset;

  if (diff != 3)

    {

      printf ("ftell did not update properly.  got %ld, expected 3\n", diff);

      result = 1;

    }

  fclose (f);

  return result;

}