* lisp/window.el (with-displayed-buffer-window): New macro.

* lisp/window.el (with-displayed-buffer-window): New macro.
(with-temp-buffer-window, with-current-buffer-window):
Use `macroexp-let2' to evaluate and bind variables
in the same order as macro arguments.
(display-buffer--action-function-custom-type): Add
`display-buffer-below-selected' and `display-buffer-at-bottom'.

* lisp/minibuffer.el (minibuffer-completion-help): Replace
`with-output-to-temp-buffer' with `with-displayed-buffer-window'
with actions that display *Completions* at-bottom when called
from the minibuffer, or below-selected in a normal buffer.
Associate `window-height' with `fit-window-to-buffer'.
Let-bind `pop-up-windows' to nil.

* lisp/dired.el (dired-mark-pop-up): Use `with-displayed-buffer-window'
instead of `with-current-buffer-window'.

Fixes: debbugs:17809