From afa5e0470c4346dbc8609de5ed51440ffb09ef36 Mon Sep 17 00:00:00 2001
From: Gerard Vermeulen <gerard.vermeulen@posteo.net>
Date: Sat, 3 Feb 2024 14:20:11 +0100
Subject: [PATCH] Add `org-ctags-disable' function to undo calling
 `org-ctags-enable'

---
 README.org | 42 +++++++++++++++++++++++++++---------------
 1 file changed, 27 insertions(+), 15 deletions(-)

diff --git a/README.org b/README.org
index 8a5634f..f9944a3 100644
--- a/README.org
+++ b/README.org
@@ -181,9 +181,6 @@ Try to load [[https://github.com/emacscollective/no-littering][no-littering]] as
 
 (require 'no-littering nil 'noerror)
 
-;; Else: Add `(tags-file-name nil)' to outermost `let*' in `org-return'.
-(setq org-modules nil)
-
 (provide 'early-init)
 ;; Emacs looks for "Local variables:" after the last "?\n?\f".
 
@@ -2283,8 +2280,8 @@ of the [[info:org#Top][Org (info)]] manual.
 I have split the initial [[https://orgmode.org/][Org-mode]] setup over several listings.  Here, follows a
 list detailing and motivating each listing:
 1. Listing [[lst:set-org-options]] handles basic [[https://orgmode.org/][Org-mode]] options.
-2. Listing [[lst:kill-org-ctags]] tries to disable ~org-ctags~ functionality without
-   side-effects.
+2. Listing [[lst:undo-org-ctags]] undoes ~org-ctags~.  See [[https://list.orgmode.org/87mt43agk6.fsf@localhost/][org-ctags land grab]] for
+   more information.
 3. Listing [[lst:setup-org-babel]] sets ~ob-core~, ~ob-latex~, and ~ob-lisp~ options.
    See [[info:org#Working with Source Code][working with source code (info)]] for Org Babel information.
 4. Listing [[lst:fake-org-babel-functions]] adds =org-babel-execute:<LANGUAGE>=
@@ -2350,9 +2347,6 @@ list detailing and motivating each listing:
                    ("\\.mm\\'" . default)
                    ("\\.x?html?\\'" . default)
                    ("\\.pdf\\'" . emacs))
-   ;; Up to here `org-modules' is nil thanks to my `early-init.el'.
-   ;; If not `org-ctags' gets loaded, which does not work on my system
-   ;; and confuses `org-return'.
    org-modules '(ol-bibtex
                  ol-doi
                  ol-eww
@@ -2363,15 +2357,33 @@ list detailing and motivating each listing:
    org-use-property-inheritance t))
 #+end_src
 
-#+caption[Kill =org-ctags=]:
-#+caption: Kill =org-ctags=.
-#+name: lst:kill-org-ctags
+#+caption[Undo calling =org-ctags-enable= ]:
+#+caption: Undo calling =org-ctags-enable=.
+#+name: lst:undo-org-ctags
 #+begin_src emacs-lisp -n :results silent
 (with-eval-after-load 'org-ctags
-  ;; This is not enough, since `org-execute-file-search-in-bibtex'
-  ;; may be a member of `org-execute-file-search-function'.
-  ;; Does this trigger `org-ctags'? Why? How to fix this?
-  (setq org-execute-file-search-functions nil))
+  ;; See also `org-link-search-must-match-exact-headline' for link searches.
+  ;; Undo calling `org-ctags-enable'.  For what may cause `org-ctags'
+  ;; loading, see: https://list.orgmode.org/87mt43agk6.fsf@localhost/
+  (defun org-ctags-disable ()
+    "Undo calling `org-ctags-enable'."
+    (put 'org-mode 'find-tag-default-function nil)
+    (setq org-ctags-enabled-p nil)
+    ;; Use the `:options' list from the `org-ctags-open-link-functions' code.
+    (let ((options '(org-ctags-find-tag
+		     org-ctags-ask-rebuild-tags-file-then-find-tag
+		     org-ctags-rebuild-tags-file-then-find-tag
+		     org-ctags-ask-append-topic
+		     org-ctags-append-topic
+		     org-ctags-ask-visit-buffer-or-file
+		     org-ctags-visit-buffer-or-file
+		     org-ctags-fail-silently))
+	  (fns org-open-link-functions))
+      (dolist (fn options)
+        (setq fns (delq fn fns)))
+      ;; Reset `org-open-link-functions' after removal of prepended functions.
+      (setq org-open-link-functions fns)))
+  (org-ctags-disable))
 #+end_src
 
 #+caption[Set =org-babel= options]: