[Patch] Fix libstdc++/7744

[Paolo Carlini]

Benjamin Kosnik wrote:

>Paolo, this looks good modulo small bits below.
>
Ok, thanks.

>>P.S. Benjamin, in my private message I forgot _your_ 9780!
>>
>Not quite sure what you mean here. Can you help me out?
>
Nothing special: only that among the most outstanding PRs there is
9780 (or 9505) which you filed a few weeks ago. I think it's
really important to work on it ASAP!

>+  // block until the asked number of bytes is available.
>
>should be
>
>+  // block until the asked number of bytes are available.
>
>
> 	      pos_type __tmp =
>-		_M_file.seekoff(__off, ios_base::cur, __mode);
>+		_M_file.seekoff(__off, ios_base::cur, __sync, __mode);
>
>
>should be
>
> 	      pos_type __tmp = _M_file.seekoff(__off, ios_base::cur, 
>                                               __sync, __mode);
>
Ok, tomorrow will change those bits and commit.

Thanks for quick reviewing,
Paolo.