'chroot', 'chdir("..")', and IMFS crash.

[Sergei Organov]

The following sequence of calls results in IMFS crash in `IMFS_eval_path'
(apparently due to NULL pointer dereference):

  char buf[SIZE];
  rtems_libio_set_private_env();
  chroot("/dev");
  chdir("/");
  chdir("..");          // Note attempt to chdir behind allowed tree
  getcwd(buf, SIZE);


Without either `chdir("..")' or `chroot("/dev")' everything works just fine.


This is latest ss-20010126 snapshot.


Sergei.