windows: prevent bytes from being passed to registry APIs
There was a TortoiseHg bug report in this area[1], and from inspection, it looks
like passing `b""` as `valname` would fail to convert to unicode. The
underlying API allows both `""` and `NULL` to return the default value for the
key.
[1] https://foss.heptapod.net/mercurial/tortoisehg/thg/-/issues/5803
.. image:: https://travis-ci.org/agronholm/cbor2.svg?branch=master
:target: https://travis-ci.org/agronholm/cbor2
:alt: Build Status
.. image:: https://coveralls.io/repos/github/agronholm/cbor2/badge.svg?branch=master
:target: https://coveralls.io/github/agronholm/cbor2?branch=master
:alt: Code Coverage
This library provides encoding and decoding for the Concise Binary Object Representation (CBOR)
(`RFC 7049`_) serialization format.
There exists another Python CBOR implementation (cbor) which is faster on CPython due to its C
extensions. On PyPy, cbor2 and cbor are almost identical in performance. The other implementation
also lacks documentation and a comprehensive test suite, does not support most standard extension
tags and is known to crash (segfault) when passed a cyclic structure (say, a list containing
itself).
.. _RFC 7049: https://tools.ietf.org/html/rfc7049
Project links
-------------
* `Documentation <http://cbor2.readthedocs.org/>`_
* `Source code <https://github.com/agronholm/cbor2>`_
* `Issue tracker <https://github.com/agronholm/cbor2/issues>`_