bug#60313: 29.0.60; Problems navigating completions from minibuffer with flex completion style

[Knut Anders Hatlen]

Selecting completions from the minibuffer with M-<up>/<down> and M-RET
doesn't always work quite the way I expect when the flex completion
style is used. For example:

1. Evaluate: (push 'flex completion-styles)

2. Type: M-x c++-mode TAB TAB
   (The *Completions* buffer now shows three alternatives: c++-mode,
   c++-ts-mode, c-or-c++-mode.)

3. Type M-<down> to select c++-mode, and then M-RET.

Expected result: c++-mode is enabled in the buffer.

Actual result: An error with the following message is raised:
‘c++-modemode’ is not a valid command name


In GNU Emacs 29.0.60 (build 2, x86_64-pc-linux-gnu, GTK+ Version
 3.24.35, cairo version 1.16.0) of 2022-12-25 built on dell
Repository revision: dad73e4de194f6f652c22fcd542d8796926d4ec6
Repository branch: emacs-29
System Description: Debian GNU/Linux bookworm/sid

Configured using:
 'configure --with-json --with-xml2 --with-modules
 --prefix=/usr/local/stow/emacs --with-pgtk --without-x
 --with-native-compilation --with-tree-sitter'

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

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

Major mode: Lisp Interaction

Minor modes in effect:
  tooltip-mode: t
  global-eldoc-mode: t
  eldoc-mode: t
  show-paren-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
  font-lock-mode: t
  blink-cursor-mode: t
  line-number-mode: t
  indent-tabs-mode: t
  transient-mark-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t

Load-path shadows:
None found.

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 text-property-search time-date mm-decode mm-bodies
mm-encode mail-parse rfc2231 mailabbrev gmm-utils mailheader sendmail
rfc2047 rfc2045 ietf-drums mm-util mail-prsvr mail-utils comp comp-cstr
warnings icons subr-x rx cl-seq cl-macs gv cl-extra help-mode
cl-loaddefs cl-lib bytecomp byte-compile 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 system-font-setting font-render-setting cairo
gtk pgtk lcms2 multi-tty make-network-process native-compile emacs)

Memory information:
((conses 16 94828 9307)
 (symbols 48 7099 0)
 (strings 32 26251 2207)
 (string-bytes 1 829967)
 (vectors 16 20715)
 (vector-slots 8 364954 10586)
 (floats 8 35 30)
 (intervals 56 230 0)
 (buffers 984 12))

-- 
Knut Anders