start = _gtk_pango_move_sentences (layout, start, -1);
if (_gtk_pango_is_inside_sentence (layout, end))
end = _gtk_pango_move_sentences (layout, end, 1);
start = _gtk_pango_move_sentences (layout, start, -1);
if (_gtk_pango_is_inside_sentence (layout, end))
end = _gtk_pango_move_sentences (layout, end, 1);