bug#63754: 29.0.91; tmm breaks when tmm-completion-prompt is nil

[Thiago Melo <tmdmelo@gmail.com>]

Issue doesn't happen with Emacs 28.

* How to reproduce

run:
emacs -Q

eval:
(setq tmm-completion-prompt nil)
(tmm-menubar) ; or `tmm-prompt' with any menu/keymap

* Backtrace

Debugger entered--Lisp error: (search-failed "Possible completions are:\n")
  search-forward("Possible completions are:\n")
  tmm-completion-delete-prompt()
  run-hooks(completion-setup-hook)
  display-completion-list((#("f==>File" 0 1 (face
(completions-first-difference))) #("e==>Edit" 0 1 (face
(completions-first-difference))) #("o==>Options" 0 1 (face
(completions-first-difference))) #("b==>Buffers" 0 1 (face
(completions-first-difference))) #("t==>Tools" 0 1 (face
(completions-first-difference))) #("l==>Lisp-Interaction" 0 1 (face
(completions-first-difference))) #("h==>Help" 0 1 (face
(completions-first-difference)))) nil nil)
  #f(compiled-function (window) #<bytecode
0x1c5839fada789551>)(#<window 9 on *Completions*>)
  window--display-buffer(#<buffer *Completions*> #<window 9 on
*Completions*> window ((window-height .
completions--fit-window-to-buffer) nil (body-function .
#f(compiled-function (window) #<bytecode 0x1c5839fada789551>))))
  display-buffer-at-bottom(#<buffer *Completions*> ((window-height .
completions--fit-window-to-buffer) nil (body-function .
#f(compiled-function (window) #<bytecode 0x1c5839fada789551>))))
  display-buffer(#<buffer *Completions*>
((display-buffer--maybe-same-window display-buffer-reuse-window
display-buffer--maybe-pop-up-frame display-buffer-at-bottom)
(window-height . completions--fit-window-to-buffer) nil (body-function
. #f(compiled-function (window) #<bytecode 0x1c5839fada789551>))))
  temp-buffer-window-show(#<buffer *Completions*>
((display-buffer--maybe-same-window display-buffer-reuse-window
display-buffer--maybe-pop-up-frame display-buffer-at-bottom)
(window-height . completions--fit-window-to-buffer) nil (body-function
. #f(compiled-function (window) #<bytecode 0x1c5839fada789551>))))
  minibuffer-completion-help()
  tmm-add-prompt()
  minibuffer-setup()
  read-from-minibuffer("Menu bar (up/down to change, PgUp to menu): "
nil (keymap (10 . minibuffer-complete-and-exit) (13 .
minibuffer-complete-and-exit) keymap (menu-bar keymap (minibuf
"Minibuf" keymap (tab menu-item "Complete" minibuffer-complete :help
"Complete as far as possible") (space menu-item "Complete Word"
minibuffer-complete-word :help "Complete at most one word") (63
menu-item "List Completions" minibuffer-completion-help :help "Display
all possible completions") "Minibuf")) (M-down .
minibuffer-next-completion) (M-up . minibuffer-previous-completion)
(27 keymap (13 . minibuffer-choose-completion) (103 keymap (27 keymap
(99 . switch-to-completions))) (118 . switch-to-completions)) (prior .
switch-to-completions) (63 . minibuffer-completion-help) (32 .
minibuffer-complete-word) (backtab . minibuffer-complete) (9 .
minibuffer-complete) keymap (menu-bar keymap (minibuf "Minibuf" keymap
(previous menu-item "Previous History Item" previous-history-element
:help "Put previous minibuffer history element in the min...") (next
menu-item "Next History Item" next-history-element :help "Put next
minibuffer history element in the minibuf...") (isearch-backward
menu-item "Isearch History Backward" isearch-backward :help
"Incrementally search minibuffer history backward") (isearch-forward
menu-item "Isearch History Forward" isearch-forward :help
"Incrementally search minibuffer history forward") (return menu-item
"Enter" exit-minibuffer :key-sequence "\15" :help "Terminate input and
exit minibuffer") (quit menu-item "Quit" abort-recursive-edit :help
"Abort input and exit minibuffer") "Minibuf")) (24 keymap (down .
minibuffer-complete-defaults) (up . minibuffer-complete-history)) (13
. exit-minibuffer) (10 . exit-minibuffer) (7 . abort-minibuffers)
(C-tab . file-cache-minibuffer-complete) (9 . self-insert-command)
(XF86Back . previous-history-element) (up .
previous-line-or-history-element) (prior . previous-history-element)
(XF86Forward . next-history-element) (down .
next-line-or-history-element) (next . next-history-element) (27 keymap
(60 . minibuffer-beginning-of-buffer) (114 .
previous-matching-history-element) (115 .
next-matching-history-element) (112 . previous-history-element) (110 .
next-history-element))) nil tmm--history ("f==>File" "e==>Edit"
"o==>Options" "b==>Buffers" "t==>Tools" "l==>Lisp-Interaction"
"h==>Help") nil)
  completing-read-default("Menu bar (up/down to change, PgUp to menu):
" #f(compiled-function (string pred action) #<bytecode
-0x81ee482af888ac8>) nil t nil tmm--history ("f==>File" "e==>Edit"
"o==>Options" "b==>Buffers" "t==>Tools" "l==>Lisp-Interaction"
"h==>Help"))
  tmm-prompt((keymap ... ... ... ... ... ... ... ...) nil nil)
  tmm-menubar()
  eval((tmm-menubar) t)
  eval-expression((tmm-menubar) nil nil 127)
  funcall-interactively(eval-expression (tmm-menubar) nil nil 127)
  call-interactively(eval-expression nil nil)
  command-execute(eval-expression)


* System information:

In GNU Emacs 29.0.91 (build 1, x86_64-pc-linux-gnu, cairo version
 1.16.0) of 2023-05-26 built on debian-x250
Repository revision: 5e7c826bfa5cb7459f5b162b498af1c57c4578e6
Repository branch: emacs-29
Windowing system distributor 'The X.Org Foundation', version 11.0.12011000
System Description: Debian GNU/Linux 11 (bullseye)

Configured using:
 'configure --prefix=/home/user/apps/emacs-29.0.91-5e7c826
 --with-x-toolkit=no --with-mailutils --with-modules
 --without-compress-install --without-toolkit-scroll-bars
 --with-native-compilation=no --with-tree-sitter'

Configured features:
ACL CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS GPM GSETTINGS HARFBUZZ JPEG
JSON LCMS2 LIBOTF LIBSELINUX LIBSYSTEMD LIBXML2 M17N_FLT MODULES NOTIFY
INOTIFY OLDXMENU PDUMPER PNG RSVG SECCOMP SOUND SQLITE3 THREADS TIFF
TREE_SITTER WEBP X11 XDBE XIM XINPUT2 XPM ZLIB

Important settings:
  value of $LANG: en_DK.UTF-8
  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 subr-x mm-decode
mm-bodies mm-encode mail-parse rfc2231 mailabbrev gmm-utils mailheader
sendmail rfc2047 rfc2045 ietf-drums mm-util mail-prsvr mail-utils
help-fns radix-tree cl-print byte-opt gv bytecomp byte-compile debug
backtrace help-mode find-func cl-loaddefs cl-lib tmm rmc iso-transl
tooltip cconv eldoc paren electric uniquify ediff-hook vc-hooks
lisp-float-type elisp-mode 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 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 lcms2 dynamic-setting system-font-setting font-render-setting
cairo xinput2 x multi-tty make-network-process emacs)

Memory information:
((conses 16 58330 6430)
 (symbols 48 6229 0)
 (strings 32 16451 1591)
 (string-bytes 1 489144)
 (vectors 16 12732)
 (vector-slots 8 171485 10082)
 (floats 8 27 43)
 (intervals 56 1188 0)
 (buffers 984 13))