Another attempt at fixing BufferedInputStream

[Jeroen Frijters]

Hi,

Since my previous attempt at fixing BufferedInputStream, I found some
more problems with it and had another go at fixing it.

If no-one complains I'll check in the attached patch.

BTW, either me or the previous author(s) were thoroughly confused about
how marking is supposed to work, so I would appreciate it if someone
could review the changes.

Regards,
Jeroen

BufferedInputStream.patch
Description: BufferedInputStream.patch