Backport commit 7d0dc3183 from Emacs

* lisp/ob-lilypond.el (org-babel-lilypond-compile-lilyfile):
Remove always-nil variable `arg-2`.

* lisp/ol-gnus.el (org-gnus-store-link):
Remove always-nil variables `newsgroup` and `xarchive`.

* lisp/ol.el (org-store-link):
Remove always-nil variable `description`.

* lisp/org-clock.el (org-clock-special-range):
Remove always-nil variables `m1` and `m`.

* lisp/org-crypt.el (org--matcher-tags-todo-only): Declare var.

* lisp/org-protocol.el (org-protocol-open-source):
Remove always-nil variable `result`.

* lisp/ox-odt.el (org-odt-format-label):
Remove always-nil variable `short-caption`.
(org-odt-link--inline-formula):
Remove always-nil variables `width` and `height`.

* lisp/ox.el (org-export--missing-definitions):
Remove always-nil variable `seen`.

* lisp/: Delete some always-nil variables
7d0dc31833d471a6f86e947d3165d3fd1452a184
Stefan Monnier
Thu Mar 11 13:07:37 2021 -0500

lisp/ob-lilypond.el

@@ -220,7 +220,7 @@ If error in compilation, attempt to mark the error in lilypond org file."
 FILE-NAME is full path to lilypond (.ly) file."
   (message "Compiling LilyPond...")
   (let ((arg-1 org-babel-lilypond-ly-command) ;program
-        (arg-2 nil)                    ;infile
+        ;; (arg-2 nil)                    ;infile
         (arg-3 "*lilypond*")           ;buffer
 	(arg-4 t)                      ;display
 	(arg-5 (if org-babel-lilypond-gen-png  "--png"  "")) ;&rest...
@@ -231,10 +231,10 @@ FILE-NAME is full path to lilypond (.ly) file."
         (arg-10 (concat "--output=" (file-name-sans-extension file-name)))
         (arg-11 file-name))
     (if test
-        `(,arg-1 ,arg-2 ,arg-3 ,arg-4 ,arg-5 ,arg-6
+        `(,arg-1 ,nil ,arg-3 ,arg-4 ,arg-5 ,arg-6 ;; arg-2
                  ,arg-7 ,arg-8 ,arg-9 ,arg-10 ,arg-11)
       (call-process
-       arg-1 arg-2 arg-3 arg-4 arg-5 arg-6
+       arg-1 nil arg-3 arg-4 arg-5 arg-6 ;; arg-2
        arg-7 arg-8 arg-9 arg-10 arg-11))))
 
 (defun org-babel-lilypond-check-for-compile-error (file-name &optional test)

lisp/ol-gnus.el

@@ -198,11 +198,11 @@ If `org-store-link' was called with a prefix arg the meaning of
 	       (to (mail-fetch-field "To"))
 	       (from (mail-fetch-field "From"))
 	       (subject (mail-fetch-field "Subject"))
-	       newsgroup xarchive)	;those are always nil for gcc
+	       ) ;; newsgroup xarchive	;those are always nil for gcc
 	   (unless gcc (error "Can not create link: No Gcc header found"))
 	   (org-link-store-props :type "gnus" :from from :subject subject
 				 :message-id id :group gcc :to to)
-	   (let ((link (org-gnus-article-link gcc newsgroup id xarchive))
+	   (let ((link (org-gnus-article-link gcc nil id nil)) ;;newsgroup xarchive
 		 (description (org-link-email-description)))
 	     (org-link-add-props :link link :description description)
 	     link)))))))

lisp/ol.el

@@ -1467,7 +1467,7 @@ non-nil."
 	    (move-beginning-of-line 2)
 	    (set-mark (point)))))
     (setq org-store-link-plist nil)
-    (let (link cpltxt desc description search custom-id agenda-link)
+    (let (link cpltxt desc search custom-id agenda-link) ;; description
       (cond
        ;; Store a link using an external link type, if any function is
        ;; available. If more than one can generate a link from current
@@ -1598,7 +1598,7 @@ non-nil."
 		      'org-create-file-search-functions))
 	(setq link (concat "file:" (abbreviate-file-name buffer-file-name)
 			   "::" search))
-	(setq cpltxt (or description link)))
+	(setq cpltxt (or link))) ;; description
 
        ((and (buffer-file-name (buffer-base-buffer)) (derived-mode-p 'org-mode))
 	(org-with-limited-levels

lisp/org-clock.el

@@ -2239,7 +2239,7 @@ have priority."
 		  ((>= month 7) 3)
 		  ((>= month 4) 2)
 		  (t 1)))
-	 m1 h1 d1 month1 y1 shiftedy shiftedm shiftedq)
+	 h1 d1 month1 y1 shiftedy shiftedm shiftedq) ;; m1
     (cond
      ((string-match "\\`[0-9]+\\'" skey)
       (setq y (string-to-number skey) month 1 d 1 key 'year))
@@ -2342,7 +2342,7 @@ have priority."
 		  (`interactive (org-read-date nil t nil "Range end? "))
 		  (`untilnow (current-time))
 		  (_ (encode-time 0
-				  (or m1 m)
+				  m ;; (or m1 m)
 				  (or h1 h)
 				  (or d1 d)
 				  (or month1 month)
@@ -2389,7 +2389,7 @@ the currently selected interval size."
 	(user-error "Line needs a :block definition before this command works")
       (let* ((b (match-beginning 1)) (e (match-end 1))
 	     (s (match-string 1))
-	     block shift ins y mw d date wp m)
+	     block shift ins y mw d date wp) ;; m
 	(cond
 	 ((equal s "yesterday") (setq s "today-1"))
 	 ((equal s "lastweek") (setq s "thisweek-1"))
@@ -2414,7 +2414,7 @@ the currently selected interval size."
 	  (cond
 	   (d (setq ins (format-time-string
 			 "%Y-%m-%d"
-			 (encode-time 0 0 0 (+ d n) m y))))
+			 (encode-time 0 0 0 (+ d n) nil y)))) ;; m
 	   ((and wp (string-match "w\\|W" wp) mw (> (length wp) 0))
 	    (require 'cal-iso)
 	    (setq date (calendar-gregorian-from-absolute

lisp/org-crypt.el

@@ -284,6 +284,8 @@ Assume `epg-context' is set."
 	 nil)))
     (_ nil)))
 
+(defvar org--matcher-tags-todo-only)
+
 ;;;###autoload
 (defun org-encrypt-entries ()
   "Encrypt all top-level entries in the current buffer."

lisp/org-protocol.el

@@ -535,7 +535,7 @@ The location for a browser's bookmark should look like this:
         encodeURIComponent(location.href)"
   ;; As we enter this function for a match on our protocol, the return value
   ;; defaults to nil.
-  (let ((result nil)
+  (let (;; (result nil)
 	(f (org-protocol-sanitize-uri
 	    (plist-get (org-protocol-parse-parameters fname nil '(:url))
 		       :url))))
@@ -586,7 +586,7 @@ The location for a browser's bookmark should look like this:
               (if (file-exists-p the-file)
                   (message "%s: permission denied!" the-file)
                 (message "%s: no such file or directory." the-file))))))
-      result)))
+      nil))) ;; FIXME: Really?
 
 
 ;;; Core functions:

lisp/ox-odt.el

@@ -2111,7 +2111,8 @@ SHORT-CAPTION are strings."
 	 (caption (let ((c (org-export-get-caption element-or-parent)))
 		    (and c (org-export-data c info))))
 	 ;; FIXME: We don't use short-caption for now
-	 (short-caption nil))
+	 ;; (short-caption nil)
+	 )
     (when (or label caption)
       (let* ((default-category
 	       (cl-case (org-element-type element)
@@ -2159,7 +2160,7 @@ SHORT-CAPTION are strings."
 			   "<text:sequence text:ref-name=\"%s\" text:name=\"%s\" text:formula=\"ooow:%s+1\" style:num-format=\"1\">%s</text:sequence>"
 			   label counter counter seqno))
 		   (?c . ,(or caption "")))))
-	       short-caption))
+	       nil)) ;; short-caption
 	    ;; Case 2: Handle Label reference.
 	    (reference
 	     (let* ((fmt (cddr (assoc-string label-style org-odt-label-styles t)))
@@ -2362,14 +2363,14 @@ used as a communication channel."
 	 ;; If yes, note down its contents.  It will go in to frame
 	 ;; description.  This quite useful for debugging.
 	 (desc (and replaces (org-element-property :value replaces)))
-	 width height)
+	 ) ;; width height
     (cond
      ((eq embed-as 'character)
-      (org-odt--render-image/formula "InlineFormula" href width height
+      (org-odt--render-image/formula "InlineFormula" href nil nil ;; width height
 				     nil nil title desc))
      (t
       (let* ((equation (org-odt--render-image/formula
-			"CaptionedDisplayFormula" href width height
+			"CaptionedDisplayFormula" href nil nil ;; width height
 			captions nil title desc))
 	     (label
 	      (let* ((org-odt-category-map-alist

lisp/ox.el

@@ -2706,9 +2706,9 @@ a list of footnote definitions or in the widened buffer."
 	       (and (or (eq (org-element-type f) 'footnote-definition)
 			(eq (org-element-property :type f) 'inline))
 		    (org-element-property :label f)))))
-	  seen)
+	  ) ;; seen
       (dolist (l (funcall list-labels tree))
-	(cond ((member l seen))
+	(cond ;; ((member l seen))
 	      ((member l known-definitions) (push l defined))
 	      (t (push l undefined)))))
     ;; Complete MISSING-DEFINITIONS by finding the definition of every