Clang 3.4 TRUNK does not compile example from draft N3690

Hi everybody,

draft standard N3690 [1] contains the following example in section 11
[class.access], p. 238:

class A {
     [snip]
     protected:
         struct B { };
};
     [snip]
struct D: A::B, A { };

The following paragraph says "the use of A::B as a base-specifier is
well-formed because D is derived from A, so checking of base-specifiers must
be deferred until the entire base-specifier-list has been seen"

Clang however complains that B is a protected member of A. I tested the
version from the Windows installer, hoping it was based on a rather current
version of the Trunk.

Is this a known issue? By design? Is there a recommended work-around?

Thanks,
Sebastian

[1] http://isocpp.org/files/papers/N3690.pdf