bug#40290: 26.3; Fix displaying inline ical attachments with no charset

[Christophe Troestler]

When an inline ical attachment contains no charset (this is the case when one 
attaches an .ics file with message mode), `gnus-article-prepare-display' fails. 
 The problem is in `gnus-icalendar-with-decoded-handle' which tries to downcase 
nil.

The attached patch fixes this.

From b78239641d965c066c8e90ca64c515ae37829031 Mon Sep 17 00:00:00 2001
From: Christophe Troestler <Christophe.Troestler@umons.ac.be>
Date: Sat, 28 Mar 2020 19:03:42 +0100
Subject: [PATCH] Fix displaying inline ical attachments with no charset
Content-Type: text/plain; charset="utf-8"

---
 lisp/gnus/gnus-icalendar.el | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lisp/gnus/gnus-icalendar.el b/lisp/gnus/gnus-icalendar.el
index 305e17fd8f..5a410d16c8 100644
--- a/lisp/gnus/gnus-icalendar.el
+++ b/lisp/gnus/gnus-icalendar.el
@@ -756,7 +756,7 @@ gnus-icalendar-with-decoded-handle
     `(let ((,charset (cdr (assoc 'charset (mm-handle-type ,handle)))))
        (with-temp-buffer
          (mm-insert-part ,handle)
-         (when (string= (downcase ,charset) "utf-8")
+         (when (and ,charset (string= (downcase ,charset) "utf-8"))
            (decode-coding-region (point-min) (point-max) 'utf-8))
          ,@body))))
 
-- 
2.25.1




In GNU Emacs 26.3 (build 2, x86_64-pc-linux-gnu, GTK+ Version 3.24.11)
 of 2019-09-22, modified by Debian built on x86-csail-01
Windowing system distributor 'The X.Org Foundation', version 11.0.12007000
System Description:     Debian GNU/Linux bullseye/sid

Recent messages:
gnus-icalendar-event-from-handle
→ nil
Saving file /home/trch/software/emacs/lisp/gnus/gnus-icalendar.el...
Wrote /home/trch/software/emacs/lisp/gnus/gnus-icalendar.el
Running git commit --amend
Diffing changes to be committed (C-g to abort diffing)
When done with a buffer, type C-c C-c
Type C-c C-c to finish, C-c C-k to cancel, and M-p and M-n to recover older 
messages
Git finished
Making completion list... [3 times]

Configured using:
 'configure --build x86_64-linux-gnu --prefix=/usr
 --sharedstatedir=/var/lib --libexecdir=/usr/lib
 --localstatedir=/var/lib --infodir=/usr/share/info
 --mandir=/usr/share/man --enable-libsystemd --with-pop=yes
 
--enable-locallisppath=/etc/emacs:/usr/local/share/emacs/26.3/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/26.3/site-lisp:/usr/share/emacs/site-lisp
 --with-sound=alsa --without-gconf --with-mailutils --build
 x86_64-linux-gnu --prefix=/usr --sharedstatedir=/var/lib
 --libexecdir=/usr/lib --localstatedir=/var/lib
 --infodir=/usr/share/info --mandir=/usr/share/man --enable-libsystemd
 --with-pop=yes
 
--enable-locallisppath=/etc/emacs:/usr/local/share/emacs/26.3/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/26.3/site-lisp:/usr/share/emacs/site-lisp
 --with-sound=alsa --without-gconf --with-mailutils --with-x=yes
 --with-x-toolkit=gtk3 --with-toolkit-scroll-bars 'CFLAGS=-g -O2
 -fdebug-prefix-map=/build/emacs-n8pPyG/emacs-26.3+1=. -fstack-protector-strong
 -Wformat -Werror=format-security -Wall' 'CPPFLAGS=-Wdate-time
 -D_FORTIFY_SOURCE=2' LDFLAGS=-Wl,-z,relro'

Configured features:
XPM JPEG TIFF GIF PNG RSVG IMAGEMAGICK SOUND GPM DBUS GSETTINGS GLIB
NOTIFY ACL LIBSELINUX GNUTLS LIBXML2 FREETYPE M17N_FLT LIBOTF XFT ZLIB
TOOLKIT_SCROLL_BARS GTK3 X11 XDBE XIM THREADS LIBSYSTEMD LCMS2

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

Major mode: mu4e:view

Minor modes in effect:
  visual-fill-column-mode: t
  TeX-PDF-mode: t
  global-magit-file-mode: t
  diff-auto-refine-mode: t
  magit-auto-revert-mode: t
  global-git-commit-mode: t
  async-bytecomp-package-mode: t
  shell-dirtrack-mode: t
  desktop-save-mode: t
  show-paren-mode: t
  global-edit-server-edit-mode: t
  tooltip-mode: t
  global-eldoc-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  buffer-read-only: t
  column-number-mode: t
  line-number-mode: t
  visual-line-mode: t
  transient-mark-mode: t

Load-path shadows:
~/software/OCaml/dune/editor-integration/emacs/dune-flymake hides 
/home/trch/.opam/4.08.1/share/emacs/site-lisp/dune-flymake
~/software/OCaml/dune/editor-integration/emacs/dune hides 
/home/trch/.opam/4.08.1/share/emacs/site-lisp/dune
/home/trch/.emacs.d/elpa/debian-el-20181020.1513/deb-view hides 
/usr/share/emacs/site-lisp/elpa/debian-el-37/deb-view
/home/trch/.emacs.d/elpa/debian-el-20181020.1513/debian-bug hides 
/usr/share/emacs/site-lisp/elpa/debian-el-37/debian-bug
/home/trch/.emacs.d/elpa/debian-el-20181020.1513/apt-utils hides 
/usr/share/emacs/site-lisp/elpa/debian-el-37/apt-utils
/home/trch/.emacs.d/elpa/debian-el-20181020.1513/preseed hides 
/usr/share/emacs/site-lisp/elpa/debian-el-37/preseed
/home/trch/.emacs.d/elpa/debian-el-20181020.1513/apt-sources hides 
/usr/share/emacs/site-lisp/elpa/debian-el-37/apt-sources
/home/trch/.emacs.d/elpa/debian-el-20181020.1513/debian-autoloads hides 
/usr/share/emacs/site-lisp/elpa/debian-el-37/debian-autoloads
/home/trch/.emacs.d/elpa/debian-el-20181020.1513/debian-el hides 
/usr/share/emacs/site-lisp/elpa/debian-el-37/debian-el
/home/trch/.emacs.d/elpa/debian-el-20181020.1513/debian-el-autoloads hides 
/usr/share/emacs/site-lisp/elpa/debian-el-37/debian-el-autoloads
/home/trch/.emacs.d/elpa/debian-el-20181020.1513/gnus-BTS hides 
/usr/share/emacs/site-lisp/elpa/debian-el-37/gnus-BTS
/home/trch/.emacs.d/elpa/debian-el-20181020.1513/debian-el-pkg hides 
/usr/share/emacs/site-lisp/elpa/debian-el-37/debian-el-pkg
/home/trch/.emacs.d/elpa/debian-el-20181020.1513/deb-view hides 
/usr/share/emacs/site-lisp/elpa-src/debian-el-37/deb-view
/home/trch/.emacs.d/elpa/debian-el-20181020.1513/apt-utils hides 
/usr/share/emacs/site-lisp/elpa-src/debian-el-37/apt-utils
/home/trch/.emacs.d/elpa/debian-el-20181020.1513/preseed hides 
/usr/share/emacs/site-lisp/elpa-src/debian-el-37/preseed
/home/trch/.emacs.d/elpa/debian-el-20181020.1513/debian-bug hides 
/usr/share/emacs/site-lisp/elpa-src/debian-el-37/debian-bug
/home/trch/.emacs.d/elpa/debian-el-20181020.1513/apt-sources hides 
/usr/share/emacs/site-lisp/elpa-src/debian-el-37/apt-sources
/home/trch/.emacs.d/elpa/debian-el-20181020.1513/debian-autoloads hides 
/usr/share/emacs/site-lisp/elpa-src/debian-el-37/debian-autoloads
/home/trch/.emacs.d/elpa/debian-el-20181020.1513/debian-el hides 
/usr/share/emacs/site-lisp/elpa-src/debian-el-37/debian-el
/home/trch/.emacs.d/elpa/debian-el-20181020.1513/debian-el-autoloads hides 
/usr/share/emacs/site-lisp/elpa-src/debian-el-37/debian-el-autoloads
/home/trch/.emacs.d/elpa/debian-el-20181020.1513/gnus-BTS hides 
/usr/share/emacs/site-lisp/elpa-src/debian-el-37/gnus-BTS
/home/trch/.emacs.d/elpa/debian-el-20181020.1513/debian-el-pkg hides 
/usr/share/emacs/site-lisp/elpa-src/debian-el-37/debian-el-pkg
/home/trch/.emacs.d/elpa/let-alist-1.0.6/let-alist hides 
/usr/share/emacs/26.3/lisp/emacs-lisp/let-alist

Features:
(shadow face-remap emacsbug whitespace magit-extras bug-reference
deuglify gnus-async gnus-cus gnus-demon gnus-diary nndiary gnus-draft
gnus-agent nnvirtual nntp gnus-cache nndraft nnmh gnus-dup gnus-fun
gnus-html url-queue url-cache mm-url gnus-kill gnus-logic gnus-mh
mh-comp mh-scan mh-gnus mh-e mh-compat mh-buffers mh-loaddefs
gnus-registry registry eieio-base gnus-salt gnus-score score-mode
gnus-srvr gnus-topic gnus-uu yenc gnus-vm gnus-msg eieio-opt help-fns
radix-tree misearch multi-isearch cl-print debug cus-start cus-load
visual-fill-column sort gnus-cite smiley shr-color color shr svg dom
mm-archive mail-extr qp latexenc org-rmail org-mhe org-irc org-info
org-gnus nnir org-docview org-bibtex org-bbdb org-w3m merlin-ac
auto-complete popup tuareg speedbar sb-image ezimage dframe caml-help
find-file reftex-auc preview prv-emacs tex-buf reftex-dcr reftex
reftex-loaddefs reftex-vars flyspell ispell latex latex-flymake
tex-ispell tex-style tex-mode vc-git flycheck json map elec-pair
font-latex tex dbus bibtex dune-flymake flymake-proc flymake compile
warnings dune skeleton smie merlin-cap merlin caml-types caml-emacs
magit-bookmark magit-submodule magit-obsolete magit-blame magit-stash
magit-reflog magit-bisect magit-push magit-pull magit-fetch magit-clone
magit-remote magit-commit magit-sequence magit-notes magit-worktree
magit-tag magit-merge magit-branch magit-reset magit-files magit-refs
magit-status magit magit-repos magit-apply magit-wip magit-log
which-func imenu magit-diff smerge-mode diff-mode magit-core
magit-autorevert magit-margin magit-transient magit-process magit-mode
transient git-commit magit-git magit-section magit-utils crm log-edit
pcvs-util add-log with-editor cl-extra async-bytecomp async pcase shell
subr-x dash erc-goodies erc erc-backend erc-compat twittering-mode url
url-proxy url-privacy url-expand url-methods url-history url-cookie
url-domsuf url-util xml org-mu4e org-agenda mu4e-icalendar
gnus-icalendar org-capture gnus-art mm-uu mml2015 mm-view mml-smime
smime dig mailcap gnus-sum gnus-group gnus-undo gnus-start gnus-cloud
nnimap nnmail mail-source tls gnutls utf7 netrc nnoo parse-time
gnus-spec gnus-int gnus-range gnus-win gnus nnheader wid-edit
mu4e-contrib esh-var esh-io esh-cmd esh-opt esh-ext esh-proc esh-arg
esh-groups eshell esh-module esh-mode esh-util bookmark pp mu4e desktop
frameset mu4e-org mu4e-main mu4e-view thingatpt browse-url mu4e-headers
mu4e-compose mu4e-context mu4e-draft mu4e-actions ido rfc2368 smtpmail
sendmail mu4e-mark mu4e-message flow-fill mu4e-proc mu4e-utils doc-view
jka-compr image-mode mu4e-lists hl-line mu4e-vars message rmc puny dired
dired-loaddefs rfc822 mml mml-sec gnus-util rmail rmail-loaddefs
mm-decode mm-bodies mm-encode mail-parse rfc2231 rfc2047 rfc2045
ietf-drums mailabbrev mail-utils gmm-utils mailheader mu4e-meta
adoc-mode tempo markup-faces org-element avl-tree generator org
org-macro org-footnote org-pcomplete pcomplete org-list org-faces
org-entities noutline outline easy-mmode org-version ob-emacs-lisp ob
ob-tangle org-src ob-ref ob-lob ob-table ob-keys ob-exp ob-comint comint
ansi-color ring ob-core ob-eval org-compat org-macs org-loaddefs
format-spec find-func epa-file epa derived epg cl quail help-mode
mm-util mail-prsvr autorevert filenotify edmacro kmacro paren icalendar
diary-lib diary-loaddefs cal-menu calendar cal-loaddefs edit-server
advice server finder-inf tex-site debian-el gh-common marshal
eieio-compat rx info package easymenu epg-config url-handlers url-parse
auth-source cl-seq eieio eieio-core cl-macs eieio-loaddefs
password-cache url-vars seq byte-opt gv bytecomp byte-compile cconv
cl-loaddefs cl-lib 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 move-toolbar gtk x-toolkit x
multi-tty make-network-process emacs)

Memory information:
((conses 16 719593 126093)
 (symbols 48 66071 1)
 (miscs 40 859 1407)
 (strings 32 237768 24461)
 (string-bytes 1 7204630)
 (vectors 16 80898)
 (vector-slots 8 2262372 260816)
 (floats 8 714 932)
 (intervals 56 7733 753)
 (buffers 992 112))

smime.p7s
Description: S/MIME cryptographic signature