Merge pull request #2016 from dalf/proxify-dataurl

    if not request.preferences.get_value('image_proxy'):

        return url

    if url.startswith('data:image/jpeg;base64,'):

    if url.startswith('data:image/'):

        # 50 is an arbitrary number to get only the beginning of the image.

        partial_base64 = url[len('data:image/'):50].split(';')

        if len(partial_base64) == 2 \

           and partial_base64[0] in ['gif', 'png', 'jpeg', 'pjpeg', 'webp', 'tiff', 'bmp']\

           and partial_base64[1].startswith('base64,'):

            return url

        else:

            return None

    if settings.get('result_proxy'):

        return proxify(url)