Clang 3.5 reports error: "reference cannot be bound to dereferenced null pointer"

src/mongo/dbtests/perftests.cpp:752:18: error: reference cannot be bound to dereferenced null pointer in well-defined C++ code; pointer may be assumed to always convert to true

      [-Werror,-Wundefined-bool-conversion]

            if( &cc() )

            ~~   ^~~~

src/mongo/db/client.h:217:20: note: 'cc' returns a reference

    inline Client& cc() {

                   ^

1 error generated.