Completion window location

[Jason Sewall]

I am using Emacs 24.1.1; when my Emacs frame is small and square-ish
with a single window, the completions buffer appears just above the
minibuffer in new horizontal window. This is great! The minibuffer,
with the next I’m trying to complete, is right next to the candidates
I’m considering.

When emacs is set to fullscreen-mode (or even when it is just a little
wider than square) or if I have the frame split horizontally, the
completions buffer takes over one of those frames temporarily. It is
still useful, but my eyes have to crawl all the way up to the top of
the screen to read the first completion candidates, then back down to
the minibuffer, ad nauseum.

I usually use emacs with a fullscreen frame, split horizontally into
two big windows. How can Emacs be persuaded to use a short, temporary
frame just above the minibuffer to show candidates? I rarely need
space to see 50-100 completion candidates at once, and if I did, I
would use some search refining or some such. I have some familiarity
with with Emacs lisp, but I haven't not much hacking and I'm not very
familiar with Emacs internals.

Cheers,
Jason