[PATCH] Enable input using variable-width encodings

[Paolo Carlini]

Pétur Runólfsson wrote:

> Hi,
>
> This patch allows basic_filebuf::underflow to handle stateless
> variable-width encodings (such as UTF-8) correctly.

Great!

Minor misspelling:

! // Allocate buffer if neccessary and move unconverted
                          ^^

Paolo.