bug#14825: 24.3.50; split-window-below miscounts window lines

[martin rudalics]

>> Currently, all window and frame sizing functions are based on canonical
>> character sizes.  This will change when we do resizing pixelwise.
>
> Resizing is only part of the problem.  There are functions that are
> unrelated to resizing, which report dimensions in canonical units.
> They should at least document this fact in the doc string, if not fix
> it.  (The fix is not too hard, btw; see window-screen-lines for an
> example.)

How would you report the size of an internal window composed of two leaf
windows showing buffers with different default character sizes?

martin