test_fieldstorage_not_multipart fails

[mtelka]

The test_fieldstorage_not_multipart fails with the following error:

_______ Test_cgi_FieldStorage_Py3_tests.test_fieldstorage_not_multipart ________

self = <test_compat.Test_cgi_FieldStorage_Py3_tests object at 0x7fffa6945950>

    def test_fieldstorage_not_multipart(self):
        from webob.compat import cgi_FieldStorage

        POSTDATA = b'{"name": "Bert"}'

        env = {
            'REQUEST_METHOD': 'POST',
            'CONTENT_TYPE': 'text/plain',
            'CONTENT_LENGTH': str(len(POSTDATA))
        }
        fp = BytesIO(POSTDATA)
>       fs = cgi_FieldStorage(fp, environ=env)

tests/test_compat.py:67:
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
/usr/lib/python3.7/cgi.py:499: in __init__
    self.read_single()
/usr/lib/python3.7/cgi.py:692: in read_single
    self.read_binary()
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

self = FieldStorage(None, None)

    def read_binary(self):
        """Internal: read binary data."""
        self.file = self.make_file()
        todo = self.length
        if todo >= 0:
            while todo > 0:
                data = self.fp.read(min(todo, self.bufsize)) # bytes
                if not isinstance(data, bytes):
                    raise ValueError("%s should return bytes, got %s"
                                     % (self.fp, type(data).__name__))
                self.bytes_read += len(data)
                if not data:
                    self.done = -1
                    break
                if self._binary_file:
                    self.file.write(data)
                else:
>                   self.file.write(data.decode())
E                   TypeError: a bytes-like object is required, not 'str'

/usr/lib/python3.7/cgi.py:717: TypeError

Tested with WebOb-1.8.7. The test fails with both Python 3.7.16 and Python 3.9.16.