The program should not let me add more than one share for the same directory.
For example, I can add a share for /tmp, and then it will let me add the exact
same share for /tmp again.
I did it this way on purpose because I think it's actually a valid choice. For
example, I think you can share a directory more than once but select a different
group of users with different privs. We need to test this.
Closing since I think this is valid behavior. Please reopen if it is not.