bug#18720: 25.0.50; `set-frame-size' reduces height instead of increases it, when set to larger value

[Drew Adams]

> Should be fixed with revision 118172 on trunk.
> 
>  > If the menu bar is wrapped to only 2 lines then the bug does not
>  > occur.
> 
> With a two lines menu bar here the frame height was reduced by one
> as well.

OK; that's in fact what I see in my setup.  But I could not repro it
from emacs -Q, for some reason.

(I replied to your msg about #15174 before reading this.  Great that
both are fixed. Thx.)