rem: if (*how == 'r') { have_read_stdin = 1; fp = stdin; } else fp = stdout;
add: have_read_stdin = true; fp = stdin;
context: xfopen (const char *file, const char *how){  FILE *fp;  if (STREQ (file, "-"))    {      if (*how == 'r')	{	  have_read_stdin = 1;	  fp = stdin;	}      else	fp = stdout;    }  else    {      if ((fp = fopen_safer (file, how)) == NULL)	die (_("open failed"), file);    }  return fp;}