Corrupted sound with QAudioOutput and opensl es backend

QAudioOutput may output corrupted sound under opensl es backend when using push mode.
The problem is triggered in QOpenSLESAudioOutput::writeData()

    const int index = m_nextBuffer * m_bufferSize;
    ::memcpy(m_buffers + index, data, len);
    const SLuint32 res = (*m_bufferQueueItf)->Enqueue(m_bufferQueueItf,
                                                      m_buffers + index,
                                                      len);

    if (res == SL_RESULT_BUFFER_INSUFFICIENT)
        return 0;

    if (res != SL_RESULT_SUCCESS) {
        setError(QAudio::FatalError);
        destroyPlayer();
        return -1;
    }

    m_processedBytes += len;
    m_availableBuffers.fetchAndAddRelaxed(-1);
    setState(QAudio::ActiveState);
    setError(QAudio::NoError);
    m_nextBuffer = (m_nextBuffer + 1) % BUFFER_COUNT;

As we can see, if opensl es can't enqueue more buffer, it will return SL_RESULT_BUFFER_INSUFFICIENT, and QOpenSLESAudioOutput::writeData() will return 0 to notify user nothing has been written to QAudioOutput object, but the problem is m_buffers has been written with data user provided and the old content may not been playback yet! that will cause corrupted sound. I think we should check m_availableBuffers before memcpy the data.
As a workaround one can check QAudioOutput::bytesFree() before calling QIODevice::write() in push mode to avoid this problem.