Subject: 28.2; Minibuffer content is sometimes unexpectedly partially hidden

From: Markus Triska <[email-masked]>
Date: Fri, 08 Dec 2023 20:03:32 +0100

To reproduce the issue, please start Emacs with:

    $ emacs -Q

Then put the following form in the *scratch* buffer and evaluate it with
C-x e:

    (let ((f (selected-frame)))
      (with-selected-frame (make-frame)
        (switch-to-buffer (get-buffer-create "other")))
      (select-frame-set-input-focus f)
      (let ((win (get-buffer-window "other" t)))
        (when win
          (with-selected-window win
            (recenter 0)))
        (with-selected-window (minibuffer-window)
          (unwind-protect
              (progn
                (setq-local face-remapping-alist `((default :height 2.0)))
                (insert "hello")
                (read-key))
            (erase-buffer)))))

"hello" is shown in the minibuffer, but it is partially hidden.

For comparison, in Emacs 28.1, "hello" is fully visible.

Can you reproduce this issue, and if possible, could you please restore
the behaviour of Emacs 28.1 and earlier versions for this example?

Thank you and all the best,
Markus

In GNU Emacs 28.2 (build 1, x86_64-pc-linux-gnu, X toolkit, Xaw scroll bars)
 of 2023-12-08 built on mt-book
Windowing system distributor 'The X.Org Foundation', version 11.0.12201003
System Description: Ubuntu 23.10

Configured using:
 'configure --with-x-toolkit=lucid --with-gif=no --with-tiff=no
 --with-gnutls=no'

Configured features:
FREETYPE GMP JPEG LIBXML2 MODULES NOTIFY INOTIFY PDUMPER PNG SECCOMP
SOUND THREADS TOOLKIT_SCROLL_BARS X11 XDBE XFT XIM XPM LUCID ZLIB

Important settings:
  value of $LC_MONETARY: de_DE.UTF-8
  value of $LC_NUMERIC: de_DE.UTF-8
  value of $LC_TIME: de_DE.UTF-8
  value of $LANG: en_US.UTF-8
  value of $XMODIFIERS: @im=ibus
  locale-coding-system: utf-8-unix