Problem with 'template' as a qualifier

[Rodolfo Lima]

Hi, I'm having with a rather obscure template instantiation which uses 
the keyword 'template' as a qualifier.

After some simplification, it boils down to:

struct A
{
     template <class T> struct B
     {
         typedef T type;
     };
};

template <class T> void f()
{
     f<typename T::template B<int>::type>();
}

int main()
{
     f<A>();
}

g++-4.3.0 compilation fails with the following error messages:

g++-4.3.0 test.cpp -o test
test.cpp: In function 'void f() [with T = int]':
test.cpp:11:   instantiated from 'void f() [with T = A]'
test.cpp:16:   instantiated from here
test.cpp:11: error: 'int' is not a class, struct, or union type

But if we change

f<typename T::template B<int>::type>()

to

f<typename T::template B<A>::type>()

it compiles fine.

Why is it so? Is the original case an indication of a g++ bug or this is 
a dark corner case of the language?

Regards,
Rodolfo Lima.