if ( n <= 0 ) {
                    return (int) ( ( this.fp - start ) > 0L ? this.fp - start : -1 );
                }
                this.fp += n;
                len -= n;
                response.adjustOffset(n);
            }
            while ( len > blockSize && n == r );
            // this used to be len > 0, but this is BS:
            // - InputStream.read gives no such guarantee

                    return (int) ( ( this.fp - start ) > 0L ? this.fp - start : -1 );
                }
                this.fp += n;
                len -= n;
                off += n;
                response.adjustOffset(n);
            }
            while ( len > 0 && n == r );

            return (int) ( this.fp - start );
        }
        catch ( CIFSException e ) {
            throw SmbException.wrap(e);
        }