bug#51437: 29.0.50; The annotated example of a complete working Flymake backend does not work with narrowed buffers

[Rudolf Adamkovič]

I have found (yet another) problem with the annotated example of a complete 
"working" Flymake backend.

When checking a narrowed buffer with errors outside of the narrowed region, I 
get:

┌────
│ error in process sentinel: flymake--highlight-line: Wrong type argument: 
integer-or-marker-p, nil
│ error in process sentinel: Wrong type argument: integer-or-marker-p, nil
└────

Looks like `flymake-diag-region' returns `(nil . nil)' and 
`flymake-make-diagnostic' does not like that.

TL;DR The official example does not work correctly with narrowed buffers.

Rudy


In GNU Emacs 29.0.50 (build 6, x86_64-apple-darwin20.6.0, NS appkit-2022.60 
Version 11.5.1 (Build 20G80))
 of 2021-10-24 built on Workstation.local
Repository revision: aea4af5119fdf130f1df7190478a23c6777f92a2
Repository branch: master
Windowing system distributor 'Apple', version 10.3.2022
System Description:  macOS 11.5.1

Configured using:
 'configure --with-json
 
PKG_CONFIG_PATH=/usr/local/Cellar/zlib/1.2.11/lib/pkgconfig:/usr/local/lib/pkgconfig:/opt/X11/lib/pkgconfig'

Configured features:
ACL DBUS GIF GLIB GMP GNUTLS JPEG JSON LCMS2 LIBXML2 MODULES NOTIFY
KQUEUE NS PDUMPER PNG RSVG THREADS TIFF TOOLKIT_SCROLL_BARS WEBP XIM
ZLIB

Important settings:
  value of $LANG: en_US.UTF-8
  locale-coding-system: utf-8-unix

Major mode: Message[Notmuch]

Minor modes in effect:
  flymake-mode: t
  which-key-mode: t
  corfu-global-mode: t
  corfu-mode: t
  vertico-mode: t
  marginalia-mode: t
  global-diff-hl-mode: t
  diff-hl-mode: t
  yas-global-mode: t
  yas-minor-mode: t
  global-hl-todo-mode: t
  hl-todo-mode: t
  savehist-mode: t
  global-subword-mode: t
  subword-mode: t
  save-place-mode: t
  global-auto-revert-mode: t
  delete-selection-mode: t
  mml-mode: t
  tooltip-mode: t
  global-eldoc-mode: t
  eldoc-mode: t
  show-paren-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
  size-indication-mode: t
  column-number-mode: t
  line-number-mode: t
  auto-fill-function: yas--auto-fill
  global-visual-line-mode: t
  visual-line-mode: t
  transient-mark-mode: t
  abbrev-mode: t

Load-path shadows:
/Users/salutis/.emacs.d/elpa/transient-20211025.1800/transient hides 
/Users/salutis/src/emacs/nextstep/Emacs.app/Contents/Resources/lisp/transient

Features:
(shadow emacsbug ox-md ox-odt rng-loc rng-uri rng-parse rng-match rng-dt
rng-util rng-pttrn nxml-parse nxml-ns nxml-enc xmltok nxml-util ox-latex
ox-icalendar org-agenda org-refile ox-html table ox-ascii ox-publish ox
sort bbdb-message sendmail fortune mail-extr notmuch notmuch-tree
notmuch-jump notmuch-hello notmuch-show notmuch-print notmuch-crypto
notmuch-mua notmuch-message notmuch-draft notmuch-maildir-fcc
notmuch-address notmuch-company notmuch-parser notmuch-wash coolj
notmuch-query goto-addr icalendar diary-lib diary-loaddefs notmuch-tag
crm notmuch-lib notmuch-version notmuch-compat pcase hl-line vc-mtn
vc-hg vc-bzr vc-src vc-sccs vc-svn vc-cvs vc-rcs sh-script smie
executable flymake-proc flymake project warnings org-indent image-file
image-converter disp-table char-fold cursor-sensor paredit edmacro bbdb
bbdb-site timezone modus-vivendi-theme modus-operandi-theme modus-themes
which-key corfu orderless consult-vertico vertico marginalia consult
recentf tree-widget kmacro pdf-loader diff-hl log-view pcvs-util vc-dir
ewoc vc diminish yasnippet hl-todo finder-inf org-clock oc-csl citeproc
citeproc-itemgetters citeproc-biblatex citeproc-bibtex parsebib
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citeproc-formatters citeproc-number rst compile citeproc-proc
citeproc-disamb citeproc-itemdata citeproc-generic-elements
citeproc-macro citeproc-choose citeproc-date citeproc-context
citeproc-prange citeproc-style citeproc-locale citeproc-term f
citeproc-rt citeproc-lib citeproc-s s let-alist queue dash savehist
ls-lisp cap-words superword subword saveplace autorevert filenotify
delsel elfeed-link elfeed-show elfeed-search elfeed-csv elfeed
elfeed-curl elfeed-log xml-query bookmark pp elfeed-db elfeed-lib vc-git
diff-mode vc-dispatcher org-element avl-tree generator ol-eww eww xdg
url-queue thingatpt mm-url ol-rmail ol-mhe ol-irc ol-info ol-gnus
nnselect gnus-search eieio-opt speedbar ezimage dframe gnus-art mm-uu
mml2015 mm-view mml-smime smime dig gnus-sum shr kinsoku svg dom
gnus-group gnus-undo gnus-start gnus-dbus dbus xml gnus-cloud nnimap
nnmail mail-source utf7 netrc nnoo parse-time gnus-spec gnus-int
gnus-range message rmc puny rfc822 mml mml-sec epa derived epg rfc6068
epg-config mm-decode mm-bodies mm-encode mail-parse rfc2231 mailabbrev
gmm-utils mailheader gnus-win gnus nnheader gnus-util rmail
rmail-loaddefs rfc2047 rfc2045 ietf-drums text-property-search
mail-utils mm-util mail-prsvr wid-edit ol-docview doc-view jka-compr
image-mode exif dired dired-loaddefs ol-bibtex ol-bbdb ol-w3m ol-doi
org-link-doi cl-extra help-mode org ob ob-tangle ob-ref ob-lob ob-table
ob-exp org-macro org-footnote org-src ob-comint org-pcomplete pcomplete
comint ansi-color ring org-list org-faces org-entities noutline outline
easy-mmode org-version ob-emacs-lisp ob-core ob-eval org-table oc-basic
bibtex iso8601 time-date ol rx org-keys oc org-compat advice org-macs
org-loaddefs format-spec find-func cal-menu calendar cal-loaddefs
tex-site slime-autoloads info package browse-url url url-proxy
url-privacy url-expand url-methods url-history url-cookie url-domsuf
url-util mailcap url-handlers url-parse auth-source cl-seq eieio
eieio-core cl-macs eieio-loaddefs password-cache json map url-vars seq
gv subr-x byte-opt bytecomp byte-compile cconv cl-loaddefs cl-lib
iso-transl tooltip eldoc paren electric uniquify ediff-hook vc-hooks
lisp-float-type elisp-mode 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 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 emoji-zwj 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 dbusbind kqueue cocoa ns
lcms2 multi-tty make-network-process emacs)

Memory information:
((conses 16 743594 65968)
 (symbols 48 42843 9)
 (strings 32 222286 7052)
 (string-bytes 1 6344437)
 (vectors 16 82119)
 (vector-slots 8 1722047 63625)
 (floats 8 399 286)
 (intervals 56 15568 1600)
 (buffers 992 26))

-- 
"Logic is a science of the necessary laws of thought, without which no 
employment of the understanding and the reason takes place." -- Immanuel Kant, 
1785

Rudolf Adamkovič <salutis@me.com>
Studenohorská 25
84103 Bratislava
Slovakia

[he/him]