When display-buffer-overriding-action's car is set to a function instead of
a list, display-buffer-override-next-command must ensure that the car is a
list before pushing a new element to it, otherwise the car will become a
itself a cons-cell and the clear-fun will trigger a wrong-type-argumen
error when trying to delq the action.

The error can be triggered by using some minor mode that
updates display-buffer-override-next-command (such as purpose-mode) and
then calling other-window-prefix.

The patch was created using the `emacs-29` branch.

----

In GNU Emacs 29.3.50 (build 8, x86_64-pc-linux-gnu, GTK+ Version
 3.24.41, cairo version 1.18.0) of 2024-05-27 built on thnkpd
System Description: Fedora Linux 39 (Workstation Edition)

Configured using:
 'configure --build x86_64-linux-gnu --prefix=/usr/local
 --sharedstatedir=/var/lib --localstatedir=/var/lib --enable-libsystemd
 --with-pop=yes --build x86_64-linux-gnu
 --enable-locallisppath=/etc/emacs:/usr/local/share/emacs/29/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/29/site-lisp:/usr/share/emacs/site-lisp
 --with-sound=alsa --without-gconf --with-mailutils --with-cairo
 --with-x=yes --with-x-toolkit=gtk3 --with-pgtk
 --with-toolkit-scroll-bars --without-xwidgets --with-imagemagick
 --with-native-compilation --with-tree-sitter --with-xinput2'

-- 
Rodrigo Virote Kassick
------------------------------------------------------------