id3v1 stringHandler with TagLib::FileRef

[Buganini]

Hi,
I defined my TagLib::ID3v1::StringHandler and print the result in
parse() function, it's all good.
and if TagLib::MPEG::File f(file) and f.ID3v1Tag() to get string, the
result is still good,
but if I use TagLib::FileRef f(file) and f.tag(), the returned string
is not properly decoded.

is this a bug or feature?

Thanks,
Buganini