Enable fido-mode' and do not set the initial-buffer-choice' option

README.org

@@ -209,6 +209,7 @@ of [[info:emacs#Saving Customizations][saving customizations (info)]].
  ;; Known problem: EasyPG fails to save files encrypted with GnuPG v2.4.1.
  ;; Darwin: brew install gnupg@2.2
  epg-pinentry-mode 'loopback
+ fido-mode t
  global-hl-line-mode t
  global-hl-line-sticky-flag t
  history-delete-duplicates t
@@ -216,7 +217,6 @@ of [[info:emacs#Saving Customizations][saving customizations (info)]].
  indent-tabs-mode nil
  inhibit-startup-buffer-menu t
  inhibit-startup-screen t
- initial-buffer-choice t
  initial-scratch-message ""
  isearch-lazy-count t
  kill-ring-max 300
@@ -1520,19 +1520,17 @@ configures =company= after ensuring the =company= installation.
 #+caption: Setup =company=.
 #+name: lst:setup-company
 #+begin_src emacs-lisp -n :results silent
-(when (and (ensure-package-installation 'company)
-           (fboundp 'company-mode))
+(when (ensure-package-installation 'company)
   ;; https://github.com/purcell/emacs.d/issues/778
   (setopt company-transformers '(company-sort-by-occurrence))
-  (dolist (symbol '(LaTeX-mode-hook
-                    org-mode-hook
-                    emacs-lisp-mode-hook
-                    lisp-interaction-mode-hook
-                    lisp-mode-hook
-                    python-mode-hook
-                    ielm-mode-hook
-                    sly-mrepl-mode-hook))
-    (add-hook symbol #'company-mode)))
+  (add-hook 'LaTeX-mode-hook #'company-mode)
+  (add-hook 'org-mode-hook #'company-mode)
+  (add-hook 'emacs-lisp-mode-hook #'company-mode)
+  (add-hook 'lisp-interaction-mode-hook #'company-mode)
+  (add-hook 'lisp-mode-hook #'company-mode)
+  (add-hook 'python-mode-hook #'company-mode)
+  (add-hook 'ielm-mode-hook #'company-mode)
+  (add-hook 'sly-mrepl-mode-hook #'company-mode))
 #+end_src
 
 * [[info:emacs#Search][Search and replace (info)]]
@@ -1705,7 +1703,7 @@ regexp strings.
 #+caption: Ensure =xr= installation.
 #+name: lst:ensure-xr-installation
 #+begin_src emacs-lisp -n :results silent
-(when (ensure-package-installation 'xr) t)
+(ensure-package-installation 'xr)
 #+end_src
 
 * [[info:emacs#Version Control][Version Control (info)]]
@@ -1857,8 +1855,7 @@ Listing [[lst:configure-nov]] configures [[https://depp.brause.cc/nov.el/][nov.e
 #+caption: Configure =nov=.
 #+name: lst:configure-nov
 #+begin_src emacs-lisp -n :results silent
-(when (and (ensure-package-installation 'nov)
-           (fboundp 'nov-mode))
+(when (ensure-package-installation 'nov)
   (add-to-list 'auto-mode-alist `(,(rx ".epub" eos) . nov-mode)))
 #+end_src
 
@@ -1881,8 +1878,7 @@ file.
 #+caption: Setup =pdf-tools=.
 #+name: lst:setup-pdf-tools
 #+begin_src emacs-lisp -n :results silent
-(when (and (ensure-package-installation 'pdf-tools)
-           (fboundp 'pdf-loader-install))
+(when (ensure-package-installation 'pdf-tools)
   ;; Use `pdf-loader-install' for faster startup than with `pdf-tools-install'.
   (pdf-loader-install)
 
@@ -2149,9 +2145,7 @@ list detailing and motivating each listing:
             "\\documentclass[preview]{standalone}\n")))
 
 (with-eval-after-load 'ob-lisp
-  ;; Default to `sly-eval' whenever feasible:
-  (when (and (package-installed-p 'sly)
-             (fboundp 'sly-eval))
+  (when (package-installed-p 'sly)
     (setopt org-babel-lisp-eval-fn #'sly-eval)))
 #+end_src
 
@@ -3889,9 +3883,7 @@ it for this buffer is by typing {{{kbd(C-c C-e t U)}}} to export the it to a
 #+caption: Configure =writegood-mode=.
 #+name: lst:configure-writegood-mode
 #+begin_src emacs-lisp -n :results silent
-(when (and (ensure-package-installation 'writegood-mode)
-           (fboundp 'writegood-mode))
-
+(when (ensure-package-installation 'writegood-mode)
   (add-hook 'after-init-hook
             (defun on-after-change-mode-hook-enable-writegood-mode ()
               (add-hook 'after-change-major-mode-hook
@@ -3921,15 +3913,7 @@ true in case document headlines contain links.  The code in listing
 #+name: lst:setup-which-function-mode
 #+begin_src emacs-lisp -n :results silent
 (with-eval-after-load 'which-func
-  (setopt which-func-modes
-          '(emacs-lisp-mode org-mode pdf-view-mode)))
-
-;; It looks like `python-mode' does nothing when it is an element of
-;; `which-func-modes'.
-
-;; (setopt which-func-modes t)
-
-;; (setopt which-func-display 'header) ;; AFAIU, fails on my system.
+  (setopt which-func-modes '(emacs-lisp-mode org-mode pdf-view-mode)))
 #+end_src
 
 #+caption[Define functions for ~which-func-functions~]:
@@ -4114,79 +4098,6 @@ Call `widen' after an `user-error'."
       (widen))))
 #+end_src
 
-#+caption: Real sessions for ~eval-buffer~ in ~org-src~ buffers.
-#+begin_src org -n :tangle eval-buffer-in-org-src-buffers.org
-,#+title:  Sessions for ~eval-buffer~ in ~org-src~ buffers
-,#+property: :tangle none
-
-,* Real sessions in ~org-src-mode~ buffers
-
-,#+header: :wrap "src text"
-,#+begin_src python :results output :session
-print("Hello *Python*!")
-,#+end_src
-
-,#+RESULTS:
-,#+begin_src text
-Hello *Python*!
-,#+end_src
-
-,#+header: :wrap "src text"
-,#+begin_src python :results output :session Python
-print("Hello *Python*!")
-,#+end_src
-
-,#+RESULTS:
-,#+begin_src text
-Hello *Python*!
-,#+end_src
-
-,#+header: :wrap "src text"
-,#+begin_src python :results output :session snake
-print("Hello *snake*!")
-,#+end_src
-
-,#+RESULTS:
-,#+begin_src text
-Hello *snake*!
-,#+end_src
-#+end_src
-
-#+caption: Fake sessions for ~eval-buffer~ in ~org-src~ buffers.
-#+begin_src org -n :tangle eval-buffer-in-org-src-buffers.org
-,* Fake sessions in ~org-src-mode~ buffers
-
-,#+header: :wrap "src text"
-,#+begin_src python :results output :session none
-print("Hello *none*!")
-,#+end_src
-
-,#+RESULTS:
-,#+begin_src text
-Hello *none*!
-,#+end_src
-
-,#+header: :wrap "src text"
-,#+begin_src python :results output :session :default
-print("Hello *Python* with `:default' unseen!")
-,#+end_src
-
-,#+RESULTS:
-,#+begin_src text
-Hello *Python* with `:default' unseen!
-,#+end_src
-
-,#+header: :wrap "src text"
-,#+begin_src python :results output :session ":default"
-print("Hello *Python* with `*:default*' seen!")
-,#+end_src
-
-,#+RESULTS:
-,#+begin_src text
-Hello *Python* with `*:default*' seen!
-,#+end_src
-#+end_src
-
 ** [[https://github.com/lassik/emacs-format-all-the-code#readme][Format-all]]
 :PROPERTIES:
 :CUSTOM_ID: sec:format-all