deluser: Avoid a dummy transaction

deluser

@@ -8,37 +8,32 @@ my $contra = "+donations";
 
 sub command :Tab(deluser) ($self, $cart, $command, @) {
     $command eq 'deluser' or return NEXT;
-
-    $cart->{_deluser} = 1;
-
-    # Ensure a transaction is triggered by adding one item to the cart.
-    $cart->add(0, "Forfeit remaining balance");
+    $cart->size and return REJECT, "Deluser is not available mid-transaction.";
 
     print(
         "\n",
         ">>> YOU ARE ABOUT TO FORFEIT YOUR BALANCE AND DELETE YOUR ACCOUNT! <<<\n",
         "\n",
-        "Type your name to finish.\n"
     );
 
-    return ACCEPT;
+    return "Type your name to finish", \&deluser_account;
 }
 
-sub hook_checkout_prepare($class, $cart, $account, $transaction_id, @) {
-    return if not defined $cart->{_deluser};
-
+sub deluser_account($self, $cart, $account, @) {
     my $amount = RevBank::Accounts::balance($account);
 
+    return ABORT, "No such account: $account."
+        if not defined $amount;
     return ABORT, "Can not delete an account with a negative balance."
         if ($amount < 0);
 
+    $cart->{_deluser} = 1;
     $cart
         ->add(-$amount, "Forfeit remaining balance")
         ->add_contra($contra, +$amount, "Delete account \$you");
+    $cart->checkout($account);
 
-    # Not having this bare return here results in "returned an unsupported value". The returned
-    # value seems to be a cart entry? Why?
-    return;
+    return ACCEPT;
 }
 
 sub hook_checkout_done($class, $cart, $account, $transaction_id, @) {