🚀 go-pugleaf

In GNU Emacs 19.27.1 (sparc-sun-solaris2.3) of Thu Sep 15 1994 on everest

I have (minibuffer . nil) in my default- and initial-frame-alist, and
(minibuffer . only) in my minibuffer-frame-alist.

I use shrink-window-if-larger-than-buffer inside my
temp-buffer-show-function, as shown at the end of this message.

Upon switching to 19.27 (from 19.22), I find that I get an error:
Signalling: (wrong-type-argument window-live-p only)
  window-edges(only)
  shrink-window-if-larger-than-buffer(#<window 8 on *Backtrace*>)
  (let ((win ...)) (shrink-window-if-larger-than-buffer win))
  (if (equal (window-buffer ...) buf) buf (delete-windows-on buf t) (let (...) (shrink-window-if-larger-than-buffer win)))
  temp-buffer-show-small(#<buffer *Completions*>)
  minibuffer-complete()
  call-interactively(minibuffer-complete)
  execute-extended-command(nil)
  call-interactively(execute-extended-command)

In window.el, shrink-window-if-larger-than-buffer is setting `mini' by
looking up the current frame parameters, then assuming the result is a
window.  In this case, that clearly isn't desirable.  I don't properly
understand what this code is doing, but I suspect the root of the
confusion is that frame-parameters is being done on the selected
frame, when it should in fact be done on the frame of the window to be
shrunk.

Detailed recipe to reproduce the bug:
Create a .emacs containing just the following:

    (setq default-frame-alist  '((minibuffer . nil))
          minibuffer-frame-alist '((minibuffer . only) (height . 1))
          initial-frame-alist default-frame-alist)

    (defun temp-buffer-show-small (buf)
      (if (equal (window-buffer (selected-window)) buf)
          buf
        (delete-windows-on buf t)
        (let ((win (display-buffer buf)))
          (shrink-window-if-larger-than-buffer win))))

    (setq temp-buffer-show-function 'temp-buffer-show-small)

Start emacs (without -q), then type M-x s e t - TAB

Ray