> Here is first screenshot how hollow cursor looks on image with margin -
> http://lgarc.narod.ru/pics/emacs-hollow-cursor.png
>
> And here is how it looks with patch applied -
> http://lgarc.narod.ru/pics/emacs-box-cursor.png
Would it be possible to keep the two thin horizontal lines when the
window is active?
Yes, creating those outlines as for hollow cursor (but keeping box cursor) would be the best solution. However it is harder to implement, I'll look into
> Without patch, look of the cursor won't change, it will remain being hollow
Did you mean "without margin" instead of "without patch"
I mean if patch is not applied, then cursor will look as on the first screenshot