rem: int fail; int nonexistent_dst = 0; int copy_into_self;
add: bool copy_into_self;
context: copy_file (const char *from, const char *to, const struct cp_options *x){  int fail;  int nonexistent_dst = 0;  int copy_into_self;  /* Allow installing from non-regular files like /dev/null.     Charles Karney reported that some Sun version of install allows that     and that sendmail's installation process relies on the behavior.  */  if (isdir (from))    {      error (0, 0, _("%s is a directory"), quote (from));      return 1;    }  fail = copy (from, to, nonexistent_dst, x, &copy_into_self, NULL);  return fail;}