Juri Linkov <juri@jurta.org> writes:

>> Use this, as there is an error in precedent patch (still using value of
>> old variable), sorry.
>
> Thanks.  I think names like `frame-or-window' and `top-or-bottom-pos'
> are quite confusing.
Yes, if you have better names tell me.

Also here on last version of patch I am using symbol instead of sexp
which is better.

> But fortunately we could avoid them.
Can you develop this?

Find here the last version of patch for review, (more or less what you
have actually) I will apply as soon Emacs is no more in feature freeze 
if no objections.