Subject: bug#68081: 30.0.50; derived-mode and display-buffer-alist

From: German Pacenza <[email-masked]>
Date: Thu, 28 Dec 2023 10:26:37 -0300

Hi,
display-buffer-alist rules that use derived-mode or major-mode are
ignored on first use.

emacs -Q:

(setq display-buffer-alist '(((derived-mode . Info-mode)
                              (display-buffer-in-side-window))))
"C-h i"
The info buffer takes the whole window
"q"
"C-h i"
The info buffer opens in side window as expected

Info and Compilation modes are affected, but Help and Man work as expected

In GNU Emacs 30.0.50 (build 3, x86_64-pc-linux-gnu, GTK+ Version
 3.24.39, cairo version 1.18.0) of 2023-12-27 built on KRONOS
Repository revision: 9e0eeb2d49ccd443bb667be9231fe932be67bb10
Repository branch: master
System Description: Manjaro Linux

Configured using:
 'configure --with-pgtk --with-native-compilation --without-gsettings
 --without-sound --without-compress-install'

Configured features:
ACL CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS GPM HARFBUZZ JPEG JSON LCMS2
LIBOTF LIBSYSTEMD LIBXML2 MODULES NATIVE_COMP NOTIFY INOTIFY PDUMPER
PGTK PNG RSVG SECCOMP SQLITE3 THREADS TIFF TOOLKIT_SCROLL_BARS
TREE_SITTER WEBP XIM GTK3 ZLIB

Important settings:
  value of $LANG: en_US.UTF-8
  locale-coding-system: utf-8-unix

Major mode: Messages

Minor modes in effect:
  savehist-mode: t
  vertico-mode: t
  delete-selection-mode: t
  spacious-padding-mode: t
  tooltip-mode: t
  global-eldoc-mode: t
  show-paren-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  minibuffer-regexp-mode: t
  buffer-read-only: t
  line-number-mode: t
  transient-mark-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t

Load-path shadows:
/home/german/.emacs.d/elpa/ef-themes-1.4.1/theme-loaddefs hides /home/german/.emacs.d/elpa/standard-themes-2.0.1/theme-loaddefs
/home/german/.emacs.d/elpa/transient-20231216.1908/transient hides /usr/local/share/emacs/30.0.50/lisp/transient
/home/german/.emacs.d/elpa/ef-themes-1.4.1/theme-loaddefs hides /usr/local/share/emacs/30.0.50/lisp/theme-loaddefs

Features:
(shadow sort mail-extr emacsbug message mailcap yank-media puny dired
dired-loaddefs rfc822 mml mml-sec password-cache epa derived epg rfc6068
epg-config gnus-util mm-decode mm-bodies mm-encode mail-parse rfc2231
mailabbrev gmm-utils mailheader sendmail rfc2047 rfc2045 ietf-drums
mm-util mail-prsvr mail-utils mule-util ibuffer ibuffer-loaddefs pulse
color misearch multi-isearch executable cl-print debug backtrace
find-func cl-macs time-date comp comp-cstr warnings icons subr-x
disp-table view jka-compr woman tabify files-x imenu compile comint
ansi-osc ring man ansi-color shortdoc pcase help-fns radix-tree
thingatpt cl-seq project byte-opt gv comp-run bytecomp byte-compile
comp-common rx cl-extra help-mode orderless cursor-sensor vc-git
diff-mode easy-mmode vc-dispatcher consult bookmark text-property-search
pp cl-loaddefs cl-lib completion-preview elec-pair savehist init
g3r-windows g3r-vertico vertico compat g3r-vc g3r-shells g3r-settings
delsel g3r-search g3r-project g3r-package g3r-modeline g3r-minibuffer
g3r-mail g3r-functions g3r-expand_region g3r-erc g3r-embark g3r-elfeed
g3r-consult g3r-completion g3r-bindings g3r-appearance spacious-padding
fontaine g3r-dark-theme init-dir info cape-autoloads
color-theme-sanityinc-tomorrow-autoloads consult-autoloads
dirvish-autoloads do-at-point-autoloads doom-themes-autoloads
eat-autoloads ef-themes-autoloads elfeed-autoloads embark-autoloads
expand-region-autoloads fontaine-autoloads golden-ratio-autoloads
hc-zenburn-theme-autoloads init-dir-autoloads kkp-autoloads
magit-autoloads git-commit-autoloads magit-section-autoloads
dash-autoloads markdown-mode-autoloads orderless-autoloads
rainbow-mode-autoloads spacious-padding-autoloads
standard-themes-autoloads sudoku-autoloads transient-dwim-autoloads
transient-autoloads vertico-autoloads with-editor-autoloads
compat-autoloads zenburn-theme-autoloads early-init rmc iso-transl
tooltip cconv eldoc paren electric uniquify ediff-hook vc-hooks
lisp-float-type elisp-mode mwheel term/pgtk-win pgtk-win term/common-win
pgtk-dnd tool-bar dnd fontset image regexp-opt fringe tabulated-list
replace newcomment text-mode lisp-mode prog-mode register page tab-bar
menu-bar rfn-eshadow isearch easymenu timer select scroll-bar mouse
jit-lock font-lock syntax font-core term/tty-colors frame minibuffer
nadvice seq simple cl-generic indonesian philippine cham georgian
utf-8-lang misc-lang vietnamese tibetan thai tai-viet lao korean
japanese eucjp-ms cp51932 hebrew greek romanian slovak czech european
ethiopic indian cyrillic chinese composite emoji-zwj charscript charprop
case-table epa-hook jka-cmpr-hook help abbrev obarray oclosure
cl-preloaded button loaddefs theme-loaddefs faces cus-face macroexp
files window text-properties overlay sha1 md5 base64 format env
code-pages mule custom widget keymap hashtable-print-readable backquote
threads dbusbind inotify dynamic-setting font-render-setting cairo gtk
pgtk lcms2 multi-tty move-toolbar make-network-process native-compile
emacs)

Memory information:
((conses 16 278958 357388) (symbols 48 12466 8)
 (strings 32 71116 11685) (string-bytes 1 2237572) (vectors 16 24796)
 (vector-slots 8 483019 124700) (floats 8 207 5606)
 (intervals 56 561 412) (buffers 992 12))

-- 
German Pacenza