c++:ICE on typename ::template scoperef combo

[Larry Evans]

The attached file causes the following error messages when submitted to the online compiler
at http://www.codesourcery.com/cgi-bin/gcc-compile.py:

Exit code: 256

Messages:

     /tmp/@16991.7.cc: In instantiation of `TdefTmpl':
     /tmp/@16991.7.cc:62: instantiated from here
     /tmp/@16991.7.cc:50: Internal error: Segmentation fault.
     Please submit a full bug report.
     See for instructions.

I believe the problem occurs in  pt.c:convert_template_argument because
no provision is made for  the following condition:

            TREE_CODE (arg) == SCOPE_REF
    && TREE_CODE (TREE_OPERAND (arg, 0)) == NAMESPACE_DECL
    && TREE_CODE (TREE_OPERAND (arg, 1)) == IDENTIFIER_NODE

the segfault occurs in convert_nontype_argument where  TREE_TYPE(expr),
where, if TREE_CODE(expr)==SCOPE_REF, a null is returned.