Changes to stdio_filebuf.cc vs 7744_xin.cc

[Benjamin Kosnik]

>I'm trying to understand the last changes to stdio_filebuf.cc, in 
>particular the use of fwrite, fread and so on in place of the low level, 
>non blocking, read, write and co...

I'm having problems with seeking and using fpos. I'm unable to debug
this at the moment, so I switched this stuff over so this patch could go
in (hopefully temporarily, until I can figure it out)

You should be able to verify this by replacing xsputn/xsgetn in
basic_file_stdio.cc to use read/write. Perhaps you could take a look at this?

>Didn't we came to the conclusion, around beginning of March (I remember 
>well some postings from Nathan) that the way to go is using the non 
>blocking read, write and co.?

That's still the goal.

>Among other things, now I'm getting a regression for 7744_xin (can you 
>reproduce it?)...

Haven't, but will look at it shortly.

-benjamin