text: /* 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_one_test (int mode)
  {
    FILE *f;
  
    f = fopen (temp_file, "r");
    if (f == NULL)
      {
        printf ("could not open temporary file: %m\n");
        return 1;
      }
  
    if (mode == 1 && ftell (f) != 0)
      {
        printf ("first ftell returned wrong position %ld\n", ftell (f));
        return 1;
      }
  
    if (fgetc (f) != '1' || fgetc (f) != '2')
      {
        puts ("fgetc failed");
        return 1;
      }
  
    if (mode == 2 && ftell (f) != 2)
      {
        printf ("second ftell returned wrong position %ld\n", ftell (f));
        return 1;
      }
  
    if (ungetc ('6', f) != '6')
      {
        puts ("ungetc failed");
        return 1;
      }
  
    if (ftell (f) != 1)
      {
        printf ("third ftell returned wrong position %ld\n", ftell (f));
        return 1;
      }
  
    if (fgetc (f) != '6')
      {
        puts ("fgetc failed");
        return 1;
      }
  
    if (ftell (f) != 2)
      {
        printf ("fourth ftell returned wrong position %ld\n", ftell (f));
        return 1;
      }
  
    fclose (f);
  
    return 0;
  }
  
  static int
  do_test (void)
  {
    int mode;
    for (mode = 0; mode <= 2; mode++)
      if (do_one_test (mode))
        return 1;
    return 0;
  }
  