self.buffer.write(b)

if self._line_buffering and (haslf or "\r" in s):

self.flush()

self._set_decoded_chars('')

self._snapshot = None

if self._decoder:

self._decoder.reset()

expected = 'linesep' + os.linesep + 'LF\nLF\nCR\rCRLF\r\n'

self.assertEqual(txt.detach().getvalue().decode('ascii'), expected)

def test_issue25862(self):

# Assertion failures occurred in tell() after read() and write().

t = self.TextIOWrapper(self.BytesIO(b'test'), encoding='ascii')

t.read(1)

t.read()

t.tell()

t = self.TextIOWrapper(self.BytesIO(b'test'), encoding='ascii')

t.read(1)

t.write('x')

t.tell()

class MemviewBytesIO(io.BytesIO):

'''A BytesIO object whose read method returns memoryviews

Fix assertion failures in the ``tell()`` method of ``io.TextIOWrapper``.

Patch by Zackery Spytz.

PyObject *dict;

} textio;

static void

textiowrapper_set_decoded_chars(textio *self, PyObject *chars);

/* A couple of specialized cases in order to bypass the slow incremental

encoding methods for the most popular encodings. */

Py_DECREF(ret);

}

textiowrapper_set_decoded_chars(self, NULL);

Py_CLEAR(self->snapshot);

if (self->decoder) {

if (result == NULL)

goto fail;

textiowrapper_set_decoded_chars(self, NULL);

Py_CLEAR(self->snapshot);

return result;

}