Previous range-checking fix removed an inequality check. This change
restores it.
Offending change was I5eb310ced58c3c64a7af2d11b80326efe5adbcab
Change-Id: Ic952c3ba5a4f7e5ab2148ec623b6f083cb7495fb
Make sure we don't have an empty string before checking if it's a
directory since this string is tainted.
Change-Id: I5eb310ced58c3c64a7af2d11b80326efe5adbcab