# Buggy code
def set_value(
    hive,
    key,
    vname=None,
    vdata=None,
    vtype="REG_SZ",
    use_32bit_registry=False,
    volatile=False,
):
    """
    Sets a registry value entry or the default value for a key.

    :param str hive: The name of the hive. Can be one of the following

        - HKEY_LOCAL_MACHINE or HKLM
        - HKEY_CURRENT_USER or HKCU
        - HKEY_USER or HKU
        - HKEY_CLASSES_ROOT or HKCR
        - HKEY_CURRENT_CONFIG or HKCC

    :param str key: The key (looks like a path) to the value name.

    :param str vname: The value name. These are the individual name/data pairs
        under the key. If not passed, the key (Default) value will be set.

    :param object vdata: The value data to be set.
        What the type of this parameter
        should be is determined by the value of the vtype
        parameter. The correspondence
        is as follows:

        .. glossary::

           REG_BINARY
               binary data (i.e. str in python version < 3 and bytes in version >=3)
           REG_DWORD
               int
           REG_EXPAND_SZ
               str
           REG_MULTI_SZ
               list of objects of type str
           REG_SZ
               str

    :param str vtype: The value type.
        The possible values of the vtype parameter are indicated
        above in the description of the vdata parameter.

    :param bool use_32bit_registry: Sets the 32bit portion of the registry on
       64bit installations. On 32bit machines this is ignored.

    :param bool volatile: When this parameter has a value of True, the registry key will be
       made volatile (i.e. it will not persist beyond a system reset or shutdown).
       This parameter only has an effect when a key is being created and at no
       other time.

    :return: Returns True if successful, False if not
    :rtype: bool

    CLI Example:

    .. code-block:: bash

        salt '*' reg.set_value HKEY_LOCAL_MACHINE 'SOFTWARE\\Salt' 'version' '2015.5.2'

    This function is strict about the type of vdata. For instance the
    the next example will fail because vtype has a value of REG_SZ and vdata
    has a type of int (as opposed to str as expected).

    CLI Example:

    .. code-block:: bash

        salt '*' reg.set_value HKEY_LOCAL_MACHINE 'SOFTWARE\\Salt' 'version' '2015.5.2' \\
        vtype=REG_SZ vdata=0

    However, this next example where vdata is properly quoted should succeed.

    CLI Example:

    .. code-block:: bash

        salt '*' reg.set_value HKEY_LOCAL_MACHINE 'SOFTWARE\\Salt' 'version' '2015.5.2' \\
        vtype=REG_SZ vdata="'0'"

    An example of using vtype REG_BINARY is as follows:

    CLI Example:

    .. code-block:: bash

        salt '*' reg.set_value HKEY_LOCAL_MACHINE 'SOFTWARE\\Salt' 'version' '2015.5.2' \\
        vtype=REG_BINARY vdata='!!binary d2hhdCdzIHRoZSBwb2ludA=='

    An example of using vtype REG_LIST is as follows:

    CLI Example:

    .. code-block:: bash

        salt '*' reg.set_value HKEY_LOCAL_MACHINE 'SOFTWARE\\Salt' 'version' '2015.5.2' \\
        vtype=REG_LIST vdata='[a,b,c]'
    """
    local_hive = _to_unicode(hive)
    local_key = _to_unicode(key)
    local_vname = _to_unicode(vname)
    local_vtype = _to_unicode(vtype)

    registry = Registry()
    hkey = registry.hkeys[local_hive]
    vtype_value = registry.vtype[local_vtype]
    access_mask = registry.registry_32[use_32bit_registry] | win32con.KEY_ALL_ACCESS

    # Check data type and cast to expected type
    # int will automatically become long on 64bit numbers
    # https://www.python.org/dev/peps/pep-0237/

    # String Types to Unicode
    if vtype_value in [1, 2]:
        local_vdata = _to_unicode(vdata)
    # Don't touch binary...
    elif vtype_value == 3:
        local_vdata = vdata
    # Make sure REG_MULTI_SZ is a list of strings
    elif vtype_value == 7:
        local_vdata = [_to_unicode(i) for i in vdata]
    # Everything else is int
    else:
        local_vdata = int(vdata)

    if volatile:
        create_options = registry.opttype["REG_OPTION_VOLATILE"]
    else:
        create_options = registry.opttype["REG_OPTION_NON_VOLATILE"]

    try:
        handle, _ = win32api.RegCreateKeyEx(
            hkey, local_key, access_mask, Options=create_options
        )
        win32api.RegSetValueEx(handle, local_vname, 0, vtype_value, local_vdata)
        win32api.RegFlushKey(handle)
        win32api.RegCloseKey(handle)
        broadcast_change()
        return True
    except (win32api.error, SystemError, ValueError, TypeError):  # pylint: disable=E0602
        log.exception("Encountered error setting registry value")
        return False


# Traceback (TypeError)
ID: reg_default_value
Function: reg.present
Name: HKLM\SOFTWARE\Salt
Result: False
Comment: An exception occurred in this state: Traceback (most recent call last):
File "c:\salt\bin\lib\site-packages\salt\state.py", line 1876, in call
**cdata['kwargs'])
File "c:\salt\bin\lib\site-packages\salt\loader.py", line 1823, in wrapper
return f(*args, **kwargs)
File "c:\salt\bin\lib\site-packages\salt\states\reg.py", line 187, in present
use_32bit_registry=use_32bit_registry)
File "c:\salt\bin\lib\site-packages\salt\modules\reg.py", line 367, in read_value
local_vname = _to_unicode(vname)
File "c:\salt\bin\lib\site-packages\salt\modules\reg.py", line 86, in _to_unicode
return salt.utils.stringutils.to_unicode(vdata, 'utf-8')
File "c:\salt\bin\lib\site-packages\salt\utils\stringutils.py", line 115, in to_unicode
raise TypeError('expected str or bytearray')
TypeError: expected str or bytearray
Started: 21:35:54.939000
Duration: 0.0 ms
Changes:

# Fixed code
def set_value(
    hive,
    key,
    vname=None,
    vdata=None,
    vtype="REG_SZ",
    use_32bit_registry=False,
    volatile=False,
):
    """
    Sets a registry value entry or the default value for a key.

    :param str hive: The name of the hive. Can be one of the following

        - HKEY_LOCAL_MACHINE or HKLM
        - HKEY_CURRENT_USER or HKCU
        - HKEY_USER or HKU
        - HKEY_CLASSES_ROOT or HKCR
        - HKEY_CURRENT_CONFIG or HKCC

    :param str key: The key (looks like a path) to the value name.

    :param str vname: The value name. These are the individual name/data pairs
        under the key. If not passed, the key (Default) value will be set.

    :param object vdata: The value data to be set.
        What the type of this parameter
        should be is determined by the value of the vtype
        parameter. The correspondence
        is as follows:

        .. glossary::

           REG_BINARY
               binary data (i.e. str in python version < 3 and bytes in version >=3)
           REG_DWORD
               int
           REG_EXPAND_SZ
               str
           REG_MULTI_SZ
               list of objects of type str
           REG_SZ
               str

    :param str vtype: The value type.
        The possible values of the vtype parameter are indicated
        above in the description of the vdata parameter.

    :param bool use_32bit_registry: Sets the 32bit portion of the registry on
       64bit installations. On 32bit machines this is ignored.

    :param bool volatile: When this parameter has a value of True, the registry key will be
       made volatile (i.e. it will not persist beyond a system reset or shutdown).
       This parameter only has an effect when a key is being created and at no
       other time.

    :return: Returns True if successful, False if not
    :rtype: bool

    CLI Example:

    .. code-block:: bash

        salt '*' reg.set_value HKEY_LOCAL_MACHINE 'SOFTWARE\\Salt' 'version' '2015.5.2'

    This function is strict about the type of vdata. For instance the
    the next example will fail because vtype has a value of REG_SZ and vdata
    has a type of int (as opposed to str as expected).

    CLI Example:

    .. code-block:: bash

        salt '*' reg.set_value HKEY_LOCAL_MACHINE 'SOFTWARE\\Salt' 'version' '2015.5.2' \\
        vtype=REG_SZ vdata=0

    However, this next example where vdata is properly quoted should succeed.

    CLI Example:

    .. code-block:: bash

        salt '*' reg.set_value HKEY_LOCAL_MACHINE 'SOFTWARE\\Salt' 'version' '2015.5.2' \\
        vtype=REG_SZ vdata="'0'"

    An example of using vtype REG_BINARY is as follows:

    CLI Example:

    .. code-block:: bash

        salt '*' reg.set_value HKEY_LOCAL_MACHINE 'SOFTWARE\\Salt' 'version' '2015.5.2' \\
        vtype=REG_BINARY vdata='!!binary d2hhdCdzIHRoZSBwb2ludA=='

    An example of using vtype REG_LIST is as follows:

    CLI Example:

    .. code-block:: bash

        salt '*' reg.set_value HKEY_LOCAL_MACHINE 'SOFTWARE\\Salt' 'version' '2015.5.2' \\
        vtype=REG_LIST vdata='[a,b,c]'
    """
    local_hive = _to_unicode(hive)
    local_key = _to_unicode(key)
    local_vname = _to_unicode(vname)
    local_vtype = _to_unicode(vtype)

    registry = Registry()
    hkey = registry.hkeys[local_hive]
    vtype_value = registry.vtype[local_vtype]
    access_mask = registry.registry_32[use_32bit_registry] | win32con.KEY_ALL_ACCESS

    # Check data type and cast to expected type
    # int will automatically become long on 64bit numbers
    # https://www.python.org/dev/peps/pep-0237/

    # String Types to Unicode
    if vtype_value in [win32con.REG_SZ, win32con.REG_EXPAND_SZ]:
        local_vdata = _to_unicode(vdata)
    # Don't touch binary...
    elif vtype_value == win32con.REG_BINARY:
        local_vdata = vdata
    # Make sure REG_MULTI_SZ is a list of strings
    elif vtype_value == win32con.REG_MULTI_SZ:
        local_vdata = [_to_unicode(i) for i in vdata]
    # Everything else is int
    else:
        local_vdata = int(vdata)

    if volatile:
        create_options = registry.opttype["REG_OPTION_VOLATILE"]
    else:
        create_options = registry.opttype["REG_OPTION_NON_VOLATILE"]

    try:
        handle, _ = win32api.RegCreateKeyEx(
            hkey, local_key, access_mask, Options=create_options
        )
        win32api.RegSetValueEx(handle, local_vname, 0, vtype_value, local_vdata)
        win32api.RegFlushKey(handle)
        win32api.RegCloseKey(handle)
        broadcast_change()
        return True
    except (win32api.error, SystemError, ValueError, TypeError):  # pylint: disable=E0602
        log.exception("Encountered error setting registry value")
        return False