signup-sql doesn't attach locker, or check validity

[price]

Below is signup-sql failing on a locker because it's not attached.

The guilty code is this in signup-sql:

    echo OK.  A MySQL account will be created for a locker of your choice that
    echo you control.  Please enter the name of the selected locker below.
    echo "(For the locker /mit/sipb, you would enter sipb)."
    printf "Locker name: "
    read lname
    lroot="/mit/$lname" 

and a later line that tries to use $lroot (==/mit/stuff).

Rather, this section should do what signup-minimal does:

        while true; do
	    printf "Locker name: "
	    read lname
	    if attach "$lname"; then
		break
	    fi
	    echo "$lname is not a valid locker name."
        done
        lroot="/mit/$lname"

which has the double benefit of attaching the locker and making sure it's attachable / an actual locker name.

athena$ signup-sql

== Welcome to the sql.mit.edu signup process ==

For documentation, including a link to the Athena rules of use,
see <http://sql.mit.edu>.

Please report problems with this signup process to sql@mit.edu.

Are you performing this signup for:
1. Your personal Athena account
2. A locker that you control (a club, a course, etc)
If you do not understand this question, you should answer '1'.
Please enter either '1' or '2' (without quotes): 2

OK. A MySQL account will be created for a locker of your choice that
you control. Please enter the name of the selected locker below.
(For the locker /mit/sipb, you would enter sipb).
Locker name: stuff
attach: /afs/athena.mit.edu/contrib/scripts attached to /mit/scripts for filesystem scripts
mkdir: "/mit/stuff/.scripts-signup": Permission denied

ERROR:
It appears as though you do not have write access to the locker <stuff>.
Contact scripts@mit.edu if you are unable to solve the problem.