Reproduce denote PR #715: denote: link previews abort org-mode startup inside a silo

matrix.sh

#!/bin/sh
# Reproduce the per-commit table in comment.md by running repro-715.sh against
# four builds of denote: upstream, each commit of PR #715 alone, and both.
#
#   sh matrix.sh /path/to/denote-repo
#
# Each build is a throwaway git worktree at the pre-PR upstream tip with the
# relevant denote.el hunks applied.  Only denote.el is applied, not the test
# files, so the two commits can be taken in isolation without conflicting.
# Every worktree is removed on exit, so nothing is left registered in the repo.

set -eu

REPO=$(cd "${1:?usage: matrix.sh /path/to/denote-repo}" && pwd)
HERE=$(cd "$(dirname "$0")" && pwd)

BASE=1004f73        # upstream tip immediately before the PR
DIRLOCAL=2fe3bcd    # Honor unapplied dir-local denote-directory
NILGUARD=d9d1257    # Do not attempt a preview for unresolvable denote links

W=$(mktemp -d "${TMPDIR:-/tmp}/denote-715-matrix.XXXXXX")

# One init directory for all four runs, so Org is byte-compiled once.
DENOTE_715_EMACSD="$W/emacs.d"
export DENOTE_715_EMACSD

cleanup() {
    for d in "$W"/*; do
        [ -d "$d" ] && git -C "$REPO" worktree remove --force "$d" 2>/dev/null || true
    done
    rm -rf "$W"
    git -C "$REPO" worktree prune
}
trap cleanup EXIT

build() {
    name=$1; shift
    git -C "$REPO" worktree add --detach "$W/$name" "$BASE" >/dev/null 2>&1
    for sha in "$@"; do
        git -C "$REPO" show "$sha" -- denote.el | git -C "$W/$name" apply -
    done
}

build base
build nilguard "$NILGUARD"
build dirlocal "$DIRLOCAL"
build both "$NILGUARD" "$DIRLOCAL"

for name in base nilguard dirlocal both; do
    echo "################ $name ################"
    sh "$HERE/repro-715.sh" "$W/$name" | sed -n '3,$p'
    echo
done

repro-715.sh

#!/bin/sh
# Reproduce the failure fixed by denote PR #715.
#
#   sh repro-715.sh /path/to/denote-checkout
#
# Everything lives in a throwaway directory: a pristine init directory whose
# only package is Org, and a two-file silo.  Your own configuration, your own
# package directory and your own notes are never read or written.
#
# Two preconditions are load-bearing, and either one alone hides the bug:
#
#   1. Org >= 9.8.  The `:preview' link parameter that denote registers
#      `denote-link-preview-file' on first shipped in Org 9.8 (released
#      2026-02-21).  On the Org bundled with every released Emacs -- 9.7.x --
#      denote's preview function is never called and there is nothing to see.
#      Stock package.el pulls a current Org from GNU ELPA below.
#
#   2. A graphical frame.  `org-link-preview-file' opens with
#      (when (display-graphic-p) ...), so under --batch the preview is skipped
#      and the run looks perfectly clean.  The probe therefore opens a real
#      frame and exits on its own.

set -eu

DENOTE=${1:?usage: repro-715.sh /path/to/denote-checkout}
DENOTE=$(cd "$DENOTE" && pwd)

T=$(mktemp -d "${TMPDIR:-/tmp}/denote-715.XXXXXX")
trap 'rm -rf "$T"' EXIT

# --------------------------------------------------------------------------
# A pristine init directory.  Stock package.el, GNU ELPA, nothing else.
#
# Set DENOTE_715_EMACSD to reuse one init directory across several runs; Org is
# then installed and byte-compiled only once.  Left unset, the init directory
# lives and dies with this run.
# --------------------------------------------------------------------------
ED=${DENOTE_715_EMACSD:-"$T/emacs.d"}
mkdir -p "$ED"
[ -f "$ED/init.el" ] || cat > "$ED/init.el" <<'EOF'
;;; init.el --- get a current Org from GNU ELPA -*- lexical-binding: t -*-
(require 'package)
(setq package-archives '(("gnu" . "https://elpa.gnu.org/packages/"))
      package-install-upgrade-built-in t)
(package-initialize)
(unless (assq 'org package-alist)
  (package-refresh-contents)
  (package-install 'org))
EOF

# --------------------------------------------------------------------------
# The silo: a dir-local `denote-directory', one note, one image to preview.
# --------------------------------------------------------------------------
mkdir -p "$T/silo" "$T/elsewhere"

cat > "$T/silo/.dir-locals.el" <<EOF
((nil . ((denote-directory . "$T/silo"))))
EOF

cat > "$T/silo/20260101T000000--note__test.org" <<'EOF'
#+title:      note
#+date:       [2026-01-01 Thu 00:00]
#+filetags:   :test:
#+identifier: 20260101T000000

[[denote:20260101T000001]]
EOF

# 1x1 transparent PNG, denote-named so the identifier resolves in the silo.
printf '%s' 'iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mNk+M9QDwADhgGAWjR9awAAAABJRU5ErkJggg==' \
  | base64 -d > "$T/silo/20260101T000001--pic__test.png"

# --------------------------------------------------------------------------
# The probe.  Opens the note the way any user would and reports what happened.
# --------------------------------------------------------------------------
cat > "$T/probe.el" <<'EOF'
;;; probe.el --- open a silo note with startup link previews -*- lexical-binding: t -*-
(let* ((dir (getenv "REPRO_DIR"))
       (note (expand-file-name "silo/20260101T000000--note__test.org" dir))
       msgs)
  ;; A global `denote-directory' that is NOT the silo -- the ordinary setup of
  ;; someone who keeps a main notes directory plus silos.  Pointed at an empty
  ;; scratch directory so the run cannot create anything under $HOME.
  (setq-default denote-directory (expand-file-name "elsewhere" dir))
  (require 'denote)
  (setq org-startup-with-link-previews t)
  (ignore-errors (find-file note))
  (setq msgs (with-current-buffer "*Messages*" (buffer-string)))
  ;; Read every field in the note's own buffer, then write.  `with-temp-file'
  ;; would otherwise report on its own temp buffer.
  (let (text)
    (with-current-buffer (get-file-buffer note)
      (setq text
            (list
             (format "Org version             %s\n" (org-version))
             (format "graphical frame         %s\n" (if (display-graphic-p) "yes" "NO -- bug cannot appear"))
             (format "major mode              %s\n" major-mode)
             (format "dir-locals applied      %s\n"
                     (if (local-variable-p 'denote-directory) "yes" "NO  <-- hack-local-variables never ran"))
             (format "denote-directory        %s\n" denote-directory)
             (format "link previews rendered  %d\n"
                     (length (seq-filter (lambda (o) (overlay-get o 'org-image-overlay))
                                         (overlays-in (point-min) (point-max)))))
             (format "error in *Messages*     %s\n"
                     (if (string-match "File mode specification error.*" msgs)
                         (match-string 0 msgs)
                       "none")))))
    (with-temp-file (expand-file-name "out.txt" dir)
      (apply #'insert text))))
(kill-emacs 0)
EOF

# --------------------------------------------------------------------------
# Run.  First hop is batch and only installs Org; the second opens a frame.
# --------------------------------------------------------------------------
emacs -Q --batch --init-directory="$ED" -l "$ED/init.el" \
      --eval '(require (quote org))' >/dev/null 2>&1

REPRO_DIR="$T" emacs -Q --init-directory="$ED" -l "$ED/init.el" \
      -L "$DENOTE" -l "$T/probe.el" >/dev/null 2>&1

echo "denote                  $DENOTE"
echo "denote revision         $(git -C "$DENOTE" rev-parse --short HEAD 2>/dev/null || echo 'not a git checkout')"
cat "$T/out.txt"