ACEs for inverted groups in authz rules are not applied

With the following authorization file:

[groups]
readonly = jconstant

[/]
$anonymous =
~@readonly = rw
@readonly = r

access to any repository fails for an authenticated user that is not in the @readonly group.

$ svn list --username jrandom .../repo
svn: E170001: Authorization failed

Reported on dev@ by Pavel Goran.