Subject: bug#53477: 28.0.50; what-cursor-position

From: Devon Sean McCullough <[email-masked]>
Date: Sun, 23 Jan 2022 11:08:12 -0500

; A phase-of-the-moon error

(let ((debug-on-error t))
   (find-file "/tmp/bad-character.el")
   (save-excursion
     (insert #x1F62D))
   (what-cursor-position t))

; always displays information about a popular emoji, but

(let ((debug-on-error t))
   (pop-to-buffer "bad-char")
   (save-excursion
     (insert #x1F62D))
   (what-cursor-position t))

; often bombs instead - as does c-U c-X = but not c-X =

Debugger entered--Lisp error: (cl-assertion-failed ((not (multibyte-string-p str)) nil))
   cl--assertion-failed((not (multibyte-string-p str)))
   encoded-string-description(#("😭" 0 1 (charset unicode)) nil)
   describe-char(1)
   what-cursor-position(t)
   (let ((debug-on-error t)) (pop-to-buffer "bad-char") (save-excursion (insert 128557)) (what-cursor-position t))
   eval((let ((debug-on-error t)) (pop-to-buffer "bad-char") (save-excursion (insert 128557)) (what-cursor-position t)) nil)
   elisp--eval-last-sexp(nil)
   eval-last-sexp(nil)
   funcall-interactively(eval-last-sexp nil)
   call-interactively(eval-last-sexp nil nil)
   command-execute(eval-last-sexp)

In GNU Emacs 28.0.50 (build 1, x86_64-apple-darwin18.7.0, NS appkit-1671.60 Version 10.14.6 (Build 18G95))
  of 2021-06-20 built on builder10-14.porkrind.org
Windowing system distributor 'Apple', version 10.3.1671
System Description:  Mac OS X 10.14.6

Configured using:
  'configure --with-ns '--enable-locallisppath=/Library/Application
  Support/Emacs/${version}/site-lisp:/Library/Application
  Support/Emacs/site-lisp' --with-modules'

Configured features:
ACL GMP GNUTLS JSON LIBXML2 MODULES NOTIFY KQUEUE NS PDUMPER THREADS
TOOLKIT_SCROLL_BARS ZLIB

Important settings:
   value of $LANG: en_BE@currency=USD.UTF-8
   locale-coding-system: utf-8-unix

Major mode: Fundamental

Minor modes in effect:
   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
   buffer-read-only: t
   line-number-mode: t
   transient-mark-mode: t

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug message rmc puny dired dired-loaddefs
rfc822 mml mml-sec epa derived epg epg-config gnus-util rmail
rmail-loaddefs auth-source cl-seq eieio eieio-core cl-macs
eieio-loaddefs password-cache json map text-property-search time-date
subr-x seq byte-opt gv bytecomp byte-compile cconv mm-decode mm-bodies
mm-encode mail-parse rfc2231 mailabbrev gmm-utils mailheader cl-loaddefs
cl-lib sendmail rfc2047 rfc2045 ietf-drums mm-util mail-prsvr mail-utils
iso-transl tooltip eldoc electric uniquify ediff-hook vc-hooks
lisp-float-type mwheel term/ns-win ns-win ucs-normalize mule-util
term/common-win tool-bar dnd fontset image regexp-opt fringe
tabulated-list replace newcomment text-mode elisp-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 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 cl-preloaded nadvice button
loaddefs faces cus-face macroexp files window text-properties overlay
sha1 md5 base64 format env code-pages mule custom widget
hashtable-print-readable backquote threads kqueue cocoa ns multi-tty
make-network-process emacs)

Memory information:
((conses 16 51159 5018)
  (symbols 48 6521 1)
  (strings 32 17717 1875)
  (string-bytes 1 591805)
  (vectors 16 13465)
  (vector-slots 8 175402 12038)
  (floats 8 21 47)
  (intervals 56 198 0)
  (buffers 992 11))