bug#19355: 25.0.50; limit the popup window height

[martin rudalics]

> I got the same thing with or without temp-buffer-resize-mode.
[...]
> The problematic case is when I am developing an elisp program in a
> window and do a completion-at-point for `(set-'. The popup takes up so
> much height that it often changes view in my editing buffer, i.e. move
> point to close to the top of the frame, push some buffer contents out of
> view etc.
[...]

I think I understand your problem but I don't understand how you can
still see it after the change I proposed.  Are you sure you applied it
and recompiled the associated functions?  If so, and the problem
persists, then please try to find out (1) why `fit-window-to-buffer'
apparently still gets called even if `temp-buffer-resize-mode' is off
and (2) why apparently `temp-buffer-max-width' is not observed when
`temp-buffer-resize-mode' is on.  (In both cases I usually find it best
to re-evaluate the involved files, edebug `fit-window-to-buffer' /
`resize-temp-buffer-window' and get a backtrace to find out how they got
called.)

martin