bug#32454: 27.0.50; "window-normalize-buffer-to-switch-to" error

[Live System User]

Hi,

        I get the following error when invoking "C-x C-v"
        '(find-alternate-file)' roughly, like this:

0. src/emacs -Q &

1. C-x C-r lisp/abbrev.el

2. C-X C-v lisp/*.el

window-normalize-buffer-to-switch-to: Wrong type argument: stringp,
(#<buffer abbrev.el> #<buffer align.el> #<buffer allout-widgets.el>
#<buffer allout.el> #<buffer ansi-color.el> #<buffer apropos.el>
#<buffer arc-mode.el> #<buffer array.el> #<buffer auth-source-pass.el>
#<buffer auth-source.el> ...)


         This works as expected in Emacs 26.1.

         Thanks.


In GNU Emacs 27.0.50 (build 3, x86_64-pc-linux-gnu, GTK+ Version 3.20.10)
 of 2018-08-14 built on localhost.localdomain
Repository revision: 5620d591ee67e5b31ca8d5aa0dcc1a13116b09a7
Windowing system distributor 'Fedora Project', version 11.0.11803000
System Description: Fedora 24 (Workstation Edition)

Recent messages:
Type C-x 1 to delete the help window.
Saving file /home/liveuser/.newsrc-dribble...
Wrote /home/liveuser/.newsrc-dribble [2 times]
Gnus auto-save file exists.  Do you want to read it? (y or n) n
Reading /home/liveuser/.newsrc.eld...
Configured using:
 'configure 'CFLAGS=-DMAIL_USE_LOCKF -O0 -ggdb3 -pipe -Wall
 -Werror=format-security -fexceptions -fstack-protector-strong
 --param=ssp-buffer-size=4 -grecord-gcc-switches -m64 -mtune=generic'
 LDFLAGS=-Wl,-z,relro
 --prefix=/tmp/emacs-27.0-git-master
 --with-dbus --with-gif --with-jpeg --with-png --with-rsvg --with-lcms2
 --with-tiff --with-xft --with-xpm --with-x-toolkit=gtk3 --with-gpm=yes
 --with-xwidgets --with-modules --with-json'

Configured features:
XPM JPEG TIFF GIF PNG RSVG IMAGEMAGICK SOUND GPM DBUS GSETTINGS NOTIFY
ACL LIBSELINUX GNUTLS LIBXML2 FREETYPE M17N_FLT LIBOTF XFT ZLIB
TOOLKIT_SCROLL_BARS GTK3 X11 MODULES THREADS XWIDGETS JSON LCMS2 GMP

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

Major mode: Fundamental

Minor modes in effect:
  gnus-desktop-notify-mode: t
  diff-auto-refine-mode: t
  tooltip-mode: t
  global-eldoc-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug timezone gnutls network-stream nsm
gnus-agent gnus-srvr gnus-score score-mode nnvirtual gnus-msg gnus-cache
gnus-demon nntp gnus-desktop-notify notifications dbus xml epa-file
nnreddit gnus-art mm-uu mml2015 cl sieve sieve-mode sieve-manage sasl
sasl-anonymous sasl-login sasl-plain advice nnir gnus-sum gnus-group
mm-url gnus-undo gnus-start gnus-cloud nnimap nnmail mail-source imap
rfc2104 utf7 netrc parse-time gnus-spec gnus-int gnus-range gnus-win
gnus message rmc puny format-spec rfc822 mml url url-proxy url-privacy
url-expand url-methods url-history url-cookie url-domsuf url-util
url-parse auth-source eieio eieio-core eieio-loaddefs json rx map
url-vars mm-view mml-smime smime dig mailcap mml-sec password-cache epa
epg cl-extra help-mode epg-config mm-decode mm-bodies mm-encode
mail-parse rfc2231 mailabbrev sendmail gmm-utils mailheader seq byte-opt
bytecomp byte-compile cconv wid-edit nnoo nnheader gnus-util rmail
dframe rmail-loaddefs rfc2047 rfc2045 ietf-drums mm-util mail-prsvr
mail-utils misearch multi-isearch noutline outline vc-git diff-mode
easymenu vc-dir derived ewoc vc dired desktop frameset edmacro kmacro
dired-loaddefs subr-x vc-dispatcher elec-pair cl-seq easy-mmode cl-macs
inline cl-loaddefs cl-lib gv pcase time-date mule-util tooltip eldoc
electric uniquify ediff-hook vc-hooks lisp-float-type mwheel term/x-win
x-win term/common-win x-dnd tool-bar dnd fontset image regexp-opt fringe
tabulated-list replace newcomment text-mode elisp-mode lisp-mode
prog-mode register page menu-bar rfn-eshadow isearch timer select
scroll-bar mouse jit-lock font-lock syntax facemenu font-core
term/tty-colors frame cl-generic 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 charscript charprop case-table epa-hook jka-cmpr-hook
help simple abbrev obarray minibuffer cl-preloaded nadvice loaddefs
button faces cus-face macroexp files text-properties overlay sha1 md5
base64 format env code-pages mule custom widget hashtable-print-readable
backquote threads dbusbind inotify lcms2 dynamic-setting
system-font-setting font-render-setting xwidget-internal move-toolbar
gtk x-toolkit x multi-tty make-network-process emacs)

Memory information:
((conses 16 817236 23906)
 (symbols 48 128741 0)
 (strings 32 110040 2397)
 (string-bytes 1 4243657)
 (vectors 16 12604)
 (vector-slots 8 574770 15192)
 (floats 8 261 207)
 (intervals 56 1355 70)
 (buffers 992 288)
 (heap 1024 76701 2336))