Description of problem:

In userisdnctl.c, lines 256-262, you have:
  fd = open("/dev/isdn/isdnctrl", O_RDWR);
  if (fd < 0)
    fd = open("/dev/isdnctrl", O_RDWR);
  if (fd < 0) {
    perror("Can't open /dev/isdnctrl or /dev/isdn/isdnctrl");
    exit(-1);
  }

If /dev/isdn/isdnctrl exists but cannot be opened and /dev/isdnctrl does not
exist, the error messsage will claim that neither /dev/isdnctrl nor
/dev/isdn/isdnctrl exist.

A better way to write this would be:

  int err;
  fd = open("/dev/isdn/isdnctrl", O_RDWR);
  err=errno;
  if (fd == -1 && err==ENOENT) {
    fd = open("/dev/isdnctrl", O_RDWR);
    if (fd == -1) {
      fprintf(stderr, "Can't open /dev/isdnctrl (%s) or /dev/isdn/isdnctrl (%s)",
                       strerror(err), strerror(errno));
      exit(-1);
    }
  }


Version-Release number of selected component (if applicable): 3.1-58