In certain cases we may get zero size reads (e.g. if the server sends an
rfc2217 notification without any other data).
In this situation we must not propagate the zero size read to user space
as it may be interpreted as end of input.
I haven't found a way to tell fuse that it should just ignore this read
but passing EINTR seems to work.
ttynvt_write() must on succesful writes return the number of bytes
written.
telnet_tx() always returns 0 (implicitly assuming srv_write() always
succeeds).
Kim Woelders
Frank Rolsted Jensen