According to MSDN documentation for System.IO.Stream.ReadByte(), the return value should be an unsigned byte cast to an Int32, or -1 if at the end of the stream.

However, the DataStream.ReadByte() is casting a signed byte to an Int32, which makes it produce wrong return values for bytes in the range of 0xf0...0xff.

Especially, a 0xff byte will be returned as -1 (instead of 255, as it should be) and thus incorrectly indicate end of stream.

To fix this bug, cast the result explicitly as a byte when returning, like:

return  (byte)  _buffer[_position++];