Avoid add-to-list on local variables

* lisp/gnus/nnir.el: Use lexical-binding and cl-lib.
(nnir-retrieve-headers): Use pcase.
(nnir-search-thread): Avoid add-to-list on local variables.

* lisp/gnus/smime.el: Use lexical-binding and cl-lib.
(smime-verify-region): Avoid add-to-list on local variables.

* lisp/mail/undigest.el: Use lexical-binding and cl-lib.
(rmail-digest-parse-mime, rmail-digest-rfc1153)
(rmail-digest-parse-rfc934): Avoid add-to-list on local variable.

* lisp/net/ldap.el (ldap-search): Move init into declaration.

* lisp/net/newst-backend.el (newsticker--cache-add):
Avoid add-to-list on local variables; Simplify code with `assq'.

* lisp/net/zeroconf.el: Use lexical-binding and cl-lib.
(dbus-debug): Remove declaration, unused.
(zeroconf-service-add-hook, zeroconf-service-remove-hook)
(zeroconf-service-browser-handler, zeroconf-publish-service):
Avoid add-to-list and *-hook on local variables.

* lisp/org/org-archive.el (org-all-archive-files):
* lisp/org/org-agenda.el (org-agenda-get-restriction-and-command):
Avoid add-to-list on local variables.

* lisp/org/ox-publish.el (org-publish--run-functions): New function.
(org-publish-projects): Use it to avoid run-hooks on a local variable.
(org-publish-cache-file-needs-publishing): Avoid add-to-list on
local variables.

* lisp/progmodes/ada-prj.el: Use setq instead of (set '...).
(ada-prj-load-from-file): Avoid add-to-list on local variables.

* lisp/progmodes/ada-xref.el (ada-initialize-runtime-library): Simplify.
(ada-gnat-parse-gpr, ada-parse-prj-file-1)
(ada-xref-find-in-modified-ali): Avoid add-to-list on local variables.

* lisp/progmodes/idlw-shell.el (idlwave-shell-update-bp-overlays):
Avoid add-to-list on local variables.

12 files changed, 186 insertions, 183 deletions

diff --git a/lisp/gnus/nnir.el b/lisp/gnus/nnir.el
index 536474cabc6..9640f2c746f 100644
--- a/lisp/gnus/nnir.el
+++ b/lisp/gnus/nnir.el
@@ -1,4 +1,4 @@
-;;; nnir.el --- search mail with various search engines -*- coding: utf-8 -*-
+;;; nnir.el --- Search mail with various search engines  -*- lexical-binding:t -*-
 
 ;; Copyright (C) 1998-2017 Free Software Foundation, Inc.
 
@@ -175,8 +175,7 @@
 (require 'gnus-group)
 (require 'message)
 (require 'gnus-util)
-(eval-when-compile
-  (require 'cl))
+(eval-when-compile (require 'cl-lib))
 
 ;;; Internal Variables:
 
@@ -686,18 +685,18 @@ skips all prompting."
 	       parsefunc)
 	  ;; (nnir-possibly-change-group nil server)
 	  (erase-buffer)
-	  (case (setq gnus-headers-retrieved-by
-		      (or
-		       (and
-			nnir-retrieve-headers-override-function
-			(funcall nnir-retrieve-headers-override-function
-				 artlist artgroup))
-		       (gnus-retrieve-headers artlist artgroup nil)))
-	    (nov
+	  (pcase (setq gnus-headers-retrieved-by
+                       (or
+                        (and
+                         nnir-retrieve-headers-override-function
+                         (funcall nnir-retrieve-headers-override-function
+                                  artlist artgroup))
+                        (gnus-retrieve-headers artlist artgroup nil)))
+	    ('nov
 	     (setq parsefunc 'nnheader-parse-nov))
-	    (headers
+	    ('headers
 	     (setq parsefunc 'nnheader-parse-head))
-	    (t (error "Unknown header type %s while requesting articles \
+	    (_ (error "Unknown header type %s while requesting articles \
                     of group %s" gnus-headers-retrieved-by artgroup)))
 	  (goto-char (point-min))
 	  (while (not (eobp))
@@ -831,7 +830,7 @@ skips all prompting."
   (nnir-possibly-change-group group server)
   (let (mlist)
     (dolist (action actions)
-      (destructuring-bind (range action marks) action
+      (cl-destructuring-bind (range action marks) action
         (let ((articles-by-group (nnir-categorize
                                   (gnus-uncompress-range range)
                                   nnir-article-group nnir-article-number)))
@@ -839,7 +838,9 @@ skips all prompting."
             (push (list
 		   (car artgroup)
 		   (list (gnus-compress-sequence
-			  (sort (cadr artgroup) '<)) action marks)) mlist)))))
+			  (sort (cadr artgroup) '<))
+                         action marks))
+                  mlist)))))
     (dolist (request (nnir-categorize  mlist car cadr))
       (gnus-request-set-mark (car request) (cadr request)))))
 
@@ -872,7 +873,7 @@ skips all prompting."
 		     (when (gnus-member-of-range (cdr art) read) (car art)))
 		   articleids))))
 	(dolist (mark marks)
-	  (destructuring-bind (type . range) mark
+	  (cl-destructuring-bind (type . range) mark
 	    (gnus-add-marked-articles
 	     group type
 	     (delq nil
@@ -955,7 +956,7 @@ details on the language and supported extensions."
   (save-excursion
     (let ((qstring (cdr (assq 'query query)))
           (server (cadr (gnus-server-to-method srv)))
-          (defs (caddr (gnus-server-to-method srv)))
+          (defs (nth 2 (gnus-server-to-method srv)))
           (criteria (or (cdr (assq 'criteria query))
                         (cdr (assoc nnir-imap-default-search-key
                                     nnir-imap-search-arguments))))
@@ -1056,13 +1057,13 @@ In future the following will be added to the language:
    ;; Composite term: or expression
    ((eq (car-safe expr) 'or)
     (format "OR %s %s"
-	    (nnir-imap-expr-to-imap criteria (second expr))
-	    (nnir-imap-expr-to-imap criteria (third expr))))
+	    (nnir-imap-expr-to-imap criteria (nth 1 expr))
+	    (nnir-imap-expr-to-imap criteria (nth 2 expr))))
    ;; Composite term: just the fax, mam
    ((eq (car-safe expr) 'not)
-    (format "NOT (%s)" (nnir-imap-query-to-imap criteria (rest expr))))
+    (format "NOT (%s)" (nnir-imap-query-to-imap criteria (cdr expr))))
    ;; Composite term: just expand it all.
-   ((and (not (null expr)) (listp expr))
+   ((consp expr)
     (format "(%s)" (nnir-imap-query-to-imap criteria expr)))
    ;; Complex value, give up for now.
    (t (error "Unhandled input: %S" expr))))
@@ -1223,8 +1224,8 @@ Windows NT 4.0."
              (exitstatus
               (progn
                 (message "%s args: %s" nnir-swish++-program
-                         (mapconcat 'identity (cddddr cp-list) " ")) ;; ???
-                (apply 'call-process cp-list))))
+                         (mapconcat #'identity (nthcdr 4 cp-list) " ")) ;; ???
+                (apply #'call-process cp-list))))
         (unless (or (null exitstatus)
                     (zerop exitstatus))
           (nnheader-report 'nnir "Couldn't run swish++: %s" exitstatus)
@@ -1259,7 +1260,7 @@ Windows NT 4.0."
       (message "Massaging swish++ output...done")
 
       ;; Sort by score
-      (apply 'vector
+      (apply #'vector
              (sort artlist
                    (function (lambda (x y)
                                (> (nnir-artitem-rsv x)
@@ -1310,8 +1311,8 @@ Tested with swish-e-2.0.1 on Windows NT 4.0."
              (exitstatus
               (progn
                 (message "%s args: %s" nnir-swish-e-program
-                         (mapconcat 'identity (cddddr cp-list) " "))
-                (apply 'call-process cp-list))))
+                         (mapconcat #'identity (nthcdr 4 cp-list) " "))
+                (apply #'call-process cp-list))))
         (unless (or (null exitstatus)
                     (zerop exitstatus))
           (nnheader-report 'nnir "Couldn't run swish-e: %s" exitstatus)
@@ -1354,7 +1355,7 @@ Tested with swish-e-2.0.1 on Windows NT 4.0."
       (message "Massaging swish-e output...done")
 
       ;; Sort by score
-      (apply 'vector
+      (apply #'vector
              (sort artlist
                    (function (lambda (x y)
                                (> (nnir-artitem-rsv x)
@@ -1387,8 +1388,8 @@ Tested with swish-e-2.0.1 on Windows NT 4.0."
              (exitstatus
               (progn
                 (message "%s args: %s" nnir-hyrex-program
-                         (mapconcat 'identity (cddddr cp-list) " "))
-                (apply 'call-process cp-list))))
+                         (mapconcat #'identity (nthcdr 4 cp-list) " "))
+                (apply #'call-process cp-list))))
         (unless (or (null exitstatus)
                     (zerop exitstatus))
           (nnheader-report 'nnir "Couldn't run hyrex-search: %s" exitstatus)
@@ -1421,7 +1422,7 @@ Tested with swish-e-2.0.1 on Windows NT 4.0."
 		      (string-to-number score))
 	      artlist))
       (message "Massaging hyrex-search output...done.")
-      (apply 'vector
+      (apply #'vector
 	     (sort artlist
                    (function (lambda (x y)
                                (if (string-lessp (nnir-artitem-group x)
@@ -1467,8 +1468,8 @@ Tested with Namazu 2.0.6 on a GNU/Linux system."
              (exitstatus
               (progn
                 (message "%s args: %s" nnir-namazu-program
-                         (mapconcat 'identity (cddddr cp-list) " "))
-                (apply 'call-process cp-list))))
+                         (mapconcat #'identity (nthcdr 4 cp-list) " "))
+                (apply #'call-process cp-list))))
         (unless (or (null exitstatus)
                     (zerop exitstatus))
           (nnheader-report 'nnir "Couldn't run namazu: %s" exitstatus)
@@ -1495,7 +1496,7 @@ Tested with Namazu 2.0.6 on a GNU/Linux system."
 	  (nnir-add-result group article score prefix server artlist)))
 
       ;; sort artlist by score
-      (apply 'vector
+      (apply #'vector
              (sort artlist
                    (function (lambda (x y)
                                (> (nnir-artitem-rsv x)
@@ -1543,8 +1544,8 @@ actually)."
              (exitstatus
               (progn
                 (message "%s args: %s" nnir-notmuch-program
-                         (mapconcat 'identity (cddddr cp-list) " ")) ;; ???
-                (apply 'call-process cp-list))))
+                         (mapconcat #'identity (nthcdr 4 cp-list) " ")) ;; ???
+                (apply #'call-process cp-list))))
         (unless (or (null exitstatus)
                     (zerop exitstatus))
           (nnheader-report 'nnir "Couldn't run notmuch: %s" exitstatus)
@@ -1639,7 +1640,7 @@ actually)."
 			    (art (string-to-number (car (last path)))))
 		       (while (string= "." (car path))
 			 (setq path (cdr path)))
-		       (let ((group (mapconcat 'identity
+		       (let ((group (mapconcat #'identity
 					       ;; Replace cl-func:
 					       ;; (subseq path 0 -1)
 					       (let ((end (1- (length path)))
@@ -1707,7 +1708,7 @@ actually)."
 		      (string-to-number (match-string 2 xref)) xscore)
 		     artlist)))))
 	    (forward-line 1)))
-	(apply 'vector (nreverse (delete-dups artlist)))))
+	(apply #'vector (nreverse (delete-dups artlist)))))
 
 ;;; Util Code:
 
@@ -1719,8 +1720,8 @@ actually)."
 
 (defun nnir-read-parms (nnir-search-engine)
   "Reads additional search parameters according to `nnir-engines'."
-  (let ((parmspec (caddr (assoc nnir-search-engine nnir-engines))))
-    (mapcar 'nnir-read-parm parmspec)))
+  (let ((parmspec (nth 2 (assoc nnir-search-engine nnir-engines))))
+    (mapcar #'nnir-read-parm parmspec)))
 
 (defun nnir-read-parm (parmspec)
   "Reads a single search parameter.
@@ -1728,7 +1729,7 @@ actually)."
   (let ((sym (car parmspec))
         (prompt (cdr parmspec)))
     (if (listp prompt)
-	(let* ((result (apply 'gnus-completing-read prompt))
+	(let* ((result (apply #'gnus-completing-read prompt))
 	       (mapping (or (assoc result nnir-imap-search-arguments)
 			    (cons nil nnir-imap-search-other))))
 	  (cons sym (format (cdr mapping) result)))
@@ -1736,7 +1737,7 @@ actually)."
 
 (defun nnir-run-query (specs)
   "Invoke appropriate search engine function (see `nnir-engines')."
-  (apply 'vconcat
+  (apply #'vconcat
 	 (mapcar
 	  (lambda (x)
 	    (let* ((server (car x))
@@ -1796,7 +1797,8 @@ article came from is also searched."
 	  (and registry-group
 	       (gnus-method-to-server
 		(gnus-find-method-for-group registry-group)))))
-    (when registry-server (add-to-list 'server (list registry-server)))
+    (when registry-server
+      (cl-pushnew (list registry-server) server :test #'equal))
     (gnus-group-make-nnir-group nil (list
 				     (cons 'nnir-query-spec query)
 				     (cons 'nnir-group-spec server)))
diff --git a/lisp/gnus/smime.el b/lisp/gnus/smime.el
index 56c651fa7ad..e3c284f033c 100644
--- a/lisp/gnus/smime.el
+++ b/lisp/gnus/smime.el
@@ -1,4 +1,4 @@
-;;; smime.el --- S/MIME support library
+;;; smime.el --- S/MIME support library  -*- lexical-binding:t -*-
 
 ;; Copyright (C) 2000-2017 Free Software Foundation, Inc.
 
@@ -122,7 +122,7 @@
 
 (require 'password-cache)
 
-(eval-when-compile (require 'cl))
+(eval-when-compile (require 'cl-lib))
 
 (defgroup smime nil
   "S/MIME configuration."
@@ -243,13 +243,13 @@ password under `cache-key'."
 ;; OpenSSL wrappers.
 
 (defun smime-call-openssl-region (b e buf &rest args)
-  (case (apply 'call-process-region b e smime-openssl-program nil buf nil args)
+  (pcase (apply #'call-process-region b e smime-openssl-program nil buf nil args)
     (0 t)
     (1 (message "OpenSSL: An error occurred parsing the command options.") nil)
     (2 (message "OpenSSL: One of the input files could not be read.") nil)
     (3 (message "OpenSSL: An error occurred creating the PKCS#7 file or when reading the MIME message.") nil)
     (4 (message "OpenSSL: An error occurred decrypting or verifying the message.") nil)
-    (t (error "Unknown OpenSSL exitcode") nil)))
+    (_ (error "Unknown OpenSSL exitcode"))))
 
 (defun smime-make-certfiles (certfiles)
   (if certfiles
@@ -373,7 +373,7 @@ Any details (stdout and stderr) are left in the buffer specified by
     (unless CAs
       (error "No CA configured"))
     (if smime-crl-check
-	(add-to-list 'CAs smime-crl-check))
+	(cl-pushnew smime-crl-check CAs :test #'equal))
     (if (apply 'smime-call-openssl-region b e (list smime-details-buffer t)
 	       "smime" "-verify" "-out" "/dev/null" CAs)
 	t
@@ -400,7 +400,7 @@ Any details (stderr on success, stdout and stderr on error) are left
 in the buffer specified by `smime-details-buffer'."
   (smime-new-details-buffer)
   (let ((buffer (generate-new-buffer " *smime*"))
-	CAs (passphrase (smime-ask-passphrase (expand-file-name keyfile)))
+	(passphrase (smime-ask-passphrase (expand-file-name keyfile)))
 	(tmpfile (make-temp-file "smime")))
     (if passphrase
 	(setenv "GNUS_SMIME_PASSPHRASE" passphrase))
@@ -507,7 +507,7 @@ A string or a list of strings is returned."
       (let ((curkey (car keys))
 	    (otherkeys (cdr keys)))
 	(if (string= keyfile (cadr curkey))
-	    (caddr curkey)
+	    (nth 2 curkey)
 	  (smime-get-certfiles keyfile otherkeys)))))
 
 (defun smime-buffer-as-string-region (b e)
@@ -564,25 +564,29 @@ A string or a list of strings is returned."
 	  (concat "mail=" mail)
 	  host '("userCertificate") nil))
 	(retbuf (generate-new-buffer (format "*certificate for %s*" mail)))
+        ldapstr
 	cert)
-    (if (and (>= (length ldapresult) 1)
-             (> (length (cadaar ldapresult)) 0))
+    (if (and (consp ldapresult)
+             ;; FIXME: This seems to expect a format rather different from
+             ;; the list of alists described in ldap.el.
+             (setq ldapstr (cadr (caar ldapresult)))
+             (> (length ldapstr) 0))
 	(with-current-buffer retbuf
 	  ;; Certificates on LDAP servers _should_ be in DER format,
 	  ;; but there are some servers out there that distributes the
 	  ;; certificates in PEM format (with or without
 	  ;; header/footer) so we try to handle them anyway.
-	  (if (or (string= (substring (cadaar ldapresult) 0 27)
+	  (if (or (string= (substring ldapstr 0 27)
 			   "-----BEGIN CERTIFICATE-----")
-		  (string= (substring (cadaar ldapresult) 0 3)
+		  (string= (substring ldapstr 0 3)
 			   "MII"))
 	      (setq cert
 		    (replace-regexp-in-string
 		     (concat "\\(\n\\|\r\\|-----BEGIN CERTIFICATE-----\\|"
 			     "-----END CERTIFICATE-----\\)")
 		     ""
-		     (cadaar ldapresult) nil t))
-	    (setq cert (base64-encode-string (cadaar ldapresult) t)))
+		     ldapstr nil t))
+	    (setq cert (base64-encode-string ldapstr t)))
 	  (insert "-----BEGIN CERTIFICATE-----\n")
 	  (let ((i 0) (len (length cert)))
 	    (while (> (- len 64) i)
diff --git a/lisp/mail/undigest.el b/lisp/mail/undigest.el
index c9200745e06..73d7464bc13 100644
--- a/lisp/mail/undigest.el
+++ b/lisp/mail/undigest.el
@@ -1,4 +1,4 @@
-;;; undigest.el --- digest-cracking support for the RMAIL mail reader
+;;; undigest.el --- digest-cracking support for the RMAIL mail reader  -*- lexical-binding:t -*-
 
 ;; Copyright (C) 1985-1986, 1994, 1996, 2001-2017 Free Software
 ;; Foundation, Inc.
@@ -28,6 +28,7 @@
 
 ;;; Code:
 
+(eval-when-compile (require 'cl-lib))
 (require 'rmail)
 
 (defcustom rmail-forward-separator-regex
@@ -59,7 +60,8 @@ each undigestified message as markers.")
 	       (re-search-forward
 		(concat
 		 "^Content-type: multipart/digest;"
-		 "\\s-* boundary=\"?\\([^\";\n]+\\)[\";\n]") head-end t)
+		 "\\s-* boundary=\"?\\([^\";\n]+\\)[\";\n]")
+                head-end t)
 	       (search-forward (match-string 1) nil t)))
     ;; Ok, prolog separator found
     (let ((start (make-marker))
@@ -69,7 +71,8 @@ each undigestified message as markers.")
       (while (search-forward separator nil t)
 	(move-marker start (match-beginning 0))
 	(move-marker end (match-end 0))
-	(add-to-list 'result (cons (copy-marker start) (copy-marker end t))))
+	(cl-pushnew (cons (copy-marker start) (copy-marker end t))
+                    result :test #'equal))
       ;; Return the list of marker pairs
       (nreverse result))))
 
@@ -117,8 +120,8 @@ See rmail-digest-methods."
 	  (while (search-forward separator nil t)
 	    (move-marker start (match-beginning 0))
 	    (move-marker end (match-end 0))
-	    (add-to-list 'result
-			 (cons (copy-marker start) (copy-marker end t))))
+	    (cl-pushnew (cons (copy-marker start) (copy-marker end t))
+                        result :test #'equal))
 	  ;; Undo masking of separators inside digestified messages
 	  (goto-char (point-min))
 	  (while (search-forward
@@ -139,7 +142,8 @@ See rmail-digest-methods."
       (while (search-forward separator nil t)
 	(move-marker start (match-beginning 0))
 	(move-marker end (match-end 0))
-	(add-to-list 'result (cons (copy-marker start) (copy-marker end t))))
+	(cl-pushnew (cons (copy-marker start) (copy-marker end t))
+                    result :test #'equal))
       ;; Undo masking of separators inside digestified messages
       (goto-char (point-min))
       (while (search-forward "\n- -" nil t)
diff --git a/lisp/net/ldap.el b/lisp/net/ldap.el
index f4910b1dc77..d5303387663 100644
--- a/lisp/net/ldap.el
+++ b/lisp/net/ldap.el
@@ -470,18 +470,17 @@ Additional search parameters can be specified through
   (or host
       (setq host ldap-default-host)
       (error "No LDAP host specified"))
-  (let ((host-plist (cdr (assoc host ldap-host-parameters-alist)))
-	result)
-    (setq result (ldap-search-internal `(host ,host
+  (let* ((host-plist (cdr (assoc host ldap-host-parameters-alist)))
+         (result (ldap-search-internal `(host ,host
 					 filter ,filter
                                          attributes ,attributes
                                          attrsonly ,attrsonly
                                          withdn ,withdn
-                                         ,@host-plist)))
+                                         ,@host-plist))))
     (if ldap-ignore-attribute-codings
 	result
       (mapcar (lambda (record)
-		(mapcar 'ldap-decode-attribute record))
+		(mapcar #'ldap-decode-attribute record))
 	      result))))
 
 (defun ldap-password-read (host)
diff --git a/lisp/net/newst-backend.el b/lisp/net/newst-backend.el
index 30a9e54b73e..f38c72a26b0 100644
--- a/lisp/net/newst-backend.el
+++ b/lisp/net/newst-backend.el
@@ -2124,15 +2124,12 @@ which the item got."
       (setq item (list title desc link time age position preformatted-contents
                        preformatted-title extra-elements))
       ;;(newsticker--debug-msg "Adding item %s" item)
-      (catch 'found
-        (mapc (lambda (this-feed)
-                (when (eq (car this-feed) feed-name-symbol)
-                  (setcdr this-feed (nconc (cdr this-feed) (list item)))
-                  (throw 'found this-feed)))
-              data)
-        ;; the feed is not contained
-        (add-to-list 'data (list feed-name-symbol item) t))))
-  data)
+      (let ((this-feed (assq feed-name-symbol data)))
+        (if this-feed
+            (setcdr this-feed (nconc (cdr this-feed) (list item)))
+          ;; The feed is not contained.
+          (setq data (append data (list (list feed-name-symbol item)))))))
+    data))
 
 (defun newsticker--cache-remove (data feed-symbol age)
   "Remove all entries from DATA in the feed FEED-SYMBOL with AGE.
diff --git a/lisp/net/zeroconf.el b/lisp/net/zeroconf.el
index 3db65c624eb..37816bb8881 100644
--- a/lisp/net/zeroconf.el
+++ b/lisp/net/zeroconf.el
@@ -1,4 +1,4 @@
-;;; zeroconf.el --- Service browser using Avahi.
+;;; zeroconf.el --- Service browser using Avahi.  -*- lexical-binding:t -*-
 
 ;; Copyright (C) 2008-2017 Free Software Foundation, Inc.
 
@@ -99,10 +99,7 @@
 
 ;;; Code:
 
-;;  Pacify byte-compiler.  D-Bus support in the Emacs core can be
-;; disabled with configuration option "--without-dbus".  Declare used
-;; subroutines and variables of `dbus' therefore.
-(defvar dbus-debug)
+(eval-when-compile (require 'cl-lib))
 
 (require 'dbus)
 
@@ -296,7 +293,7 @@ The key of an entry is a service type.")
 (defun zeroconf-service-add-hook (type event function)
   "Add FUNCTION to the hook of service type TYPE.
 
-EVENT must be either :new or :removed, indicating whether
+EVENT must be either `:new' or `:removed', indicating whether
 FUNCTION shall be called when a new service has been newly
 detected, or removed.
 
@@ -320,15 +317,13 @@ The attributes of SERVICE can be retrieved via the functions
 
   (cond
    ((equal event :new)
-    (let ((l-hook (gethash type zeroconf-service-added-hooks-hash nil)))
-      (add-hook 'l-hook function)
-      (puthash type l-hook zeroconf-service-added-hooks-hash)
-      (dolist (service (zeroconf-list-services type))
-	(funcall function service))))
+    (cl-pushnew function (gethash type zeroconf-service-added-hooks-hash)
+                :test #'equal)
+    (dolist (service (zeroconf-list-services type))
+      (funcall function service)))
    ((equal event :removed)
-    (let ((l-hook (gethash type zeroconf-service-removed-hooks-hash nil)))
-      (add-hook 'l-hook function)
-      (puthash type l-hook zeroconf-service-removed-hooks-hash)))
+    (cl-pushnew function (gethash type zeroconf-service-removed-hooks-hash)
+                :test #'equal))
    (t (error "EVENT must be either `:new' or `:removed'"))))
 
 (defun zeroconf-service-remove-hook (type event function)
@@ -336,16 +331,13 @@ The attributes of SERVICE can be retrieved via the functions
 
 EVENT must be either :new or :removed and has to match the event
 type used when registering FUNCTION."
-  (let* ((table (cond
-		 ((equal event :new)
-		  zeroconf-service-added-hooks-hash)
-		 ((equal event :removed)
-		  zeroconf-service-removed-hooks-hash)
-		 (t (error "EVENT must be either `:new' or `:removed'"))))
-	 (l-hook (gethash type table nil)))
-    (remove-hook 'l-hook function)
-    (if l-hook
-	(puthash type l-hook table)
+  (let* ((table (pcase event
+                  (:new zeroconf-service-added-hooks-hash)
+                  (:removed zeroconf-service-removed-hooks-hash)
+                  (_ (error "EVENT must be either `:new' or `:removed'"))))
+	 (functions (remove function (gethash type table))))
+    (if functions
+	(puthash type functions table)
       (remhash type table))))
 
 (defun zeroconf-get-host ()
@@ -580,13 +572,13 @@ DOMAIN is nil, the local domain is used."
      ((string-equal (dbus-event-member-name last-input-event) "ItemNew")
       ;; Add new service.
       (puthash key val zeroconf-services-hash)
-      (run-hook-with-args 'ahook val))
+      (dolist (f ahook) (funcall f val)))
 
      ((string-equal (dbus-event-member-name last-input-event) "ItemRemove")
       ;; Remove the service.
       (remhash key zeroconf-services-hash)
       (remhash key zeroconf-resolved-services-hash)
-      (run-hook-with-args 'rhook val)))))
+      (dolist (f rhook) (funcall f val))))))
 
 (defun zeroconf-register-service-resolver (name type)
   "Register a service resolver at the Avahi daemon."
@@ -653,7 +645,7 @@ For the description of arguments, see `zeroconf-resolved-services-hash'."
 
     ;; The TXT field has the signature "as".  Transform to "aay".
     (dolist (elt txt)
-      (add-to-list 'result (dbus-string-to-byte-array elt)))
+      (cl-pushnew (dbus-string-to-byte-array elt) result :test #'equal))
 
     ;; Add the service.
     (dbus-call-method
diff --git a/lisp/org/org-agenda.el b/lisp/org/org-agenda.el
index e119d9ffeb1..c870ddd4e43 100644
--- a/lisp/org/org-agenda.el
+++ b/lisp/org/org-agenda.el
@@ -2928,7 +2928,7 @@ L   Timeline for current buffer         #   List stuck projects (!=configure)
 		  type (nth 2 entry)
 		  match (nth 3 entry))
 	    (if (> (length key) 1)
-		(add-to-list 'prefixes (string-to-char key))
+		(pushnew (string-to-char key) prefixes :test #'equal)
 	      (setq line
 		    (format
 		     "%-4s%-14s"
diff --git a/lisp/org/org-archive.el b/lisp/org/org-archive.el
index a7afa19c0f9..39a6581046a 100644
--- a/lisp/org/org-archive.el
+++ b/lisp/org/org-archive.el
@@ -29,6 +29,7 @@
 ;;; Code:
 
 (require 'org)
+(eval-when-compile (require 'cl))
 
 (declare-function org-inlinetask-remove-END-maybe "org-inlinetask" ())
 (declare-function org-datetree-find-date-create "org-datetree" (date &optional keep-restriction))
@@ -163,11 +164,11 @@ archive file is."
 	  (setq file (org-extract-archive-file
 		      (org-match-string-no-properties 2)))
 	  (and file (> (length file) 0) (file-exists-p file)
-	       (add-to-list 'files file)))))
+	       (pushnew file files :test #'equal)))))
     (setq files (nreverse files))
     (setq file (org-extract-archive-file))
     (and file (> (length file) 0) (file-exists-p file)
-	 (add-to-list 'files file))
+	 (pushnew file files :test #'equal))
     files))
 
 (defun org-extract-archive-file (&optional location)
diff --git a/lisp/org/ox-publish.el b/lisp/org/ox-publish.el
index fdab9ac46e6..4ebc073990e 100644
--- a/lisp/org/ox-publish.el
+++ b/lisp/org/ox-publish.el
@@ -662,6 +662,13 @@ See `org-publish-projects'."
 	 filename pub-dir publishing-function base-dir)))
     (unless no-cache (org-publish-write-cache-file))))
 
+(defun org-publish--run-functions (functions)
+  (cond
+   ((null functions) nil)
+   ((functionp functions) (funcall functions))
+   ((consp functions) (mapc #'funcall functions))
+   (t (error "Neither a function nor a list: %S" functions))))
+
 (defun org-publish-projects (projects)
   "Publish all files belonging to the PROJECTS alist.
 If `:auto-sitemap' is set, publish the sitemap too.  If
@@ -690,7 +697,7 @@ If `:auto-sitemap' is set, publish the sitemap too.  If
 	    (theindex
 	     (expand-file-name "theindex.org"
 			       (plist-get project-plist :base-directory))))
-       (when preparation-function (run-hooks 'preparation-function))
+       (org-publish--run-functions preparation-function)
        (if sitemap-p (funcall sitemap-function project sitemap-filename))
        ;; Publish all files from PROJECT excepted "theindex.org".  Its
        ;; publishing will be deferred until "theindex.inc" is
@@ -704,7 +711,7 @@ If `:auto-sitemap' is set, publish the sitemap too.  If
 	 (org-publish-index-generate-theindex
 	  project (plist-get project-plist :base-directory))
 	 (org-publish-file theindex project t))
-       (when completion-function (run-hooks 'completion-function))
+       (org-publish--run-functions completion-function)
        (org-publish-write-cache-file)))
    (org-publish-expand-projects projects)))
 
@@ -1171,9 +1178,13 @@ the file including them will be republished as well."
 	(goto-char (point-min))
 	(while (re-search-forward
 		"^#\\+INCLUDE:[ \t]+\"\\([^\t\n\r\"]*\\)\"[ \t]*.*$" nil t)
-	  (let* ((included-file (expand-file-name (match-string 1))))
-	    (add-to-list 'included-files-ctime
-			 (org-publish-cache-ctime-of-src included-file) t))))
+	  (let* ((included-file (expand-file-name (match-string 1)))
+                 (ctime (org-publish-cache-ctime-of-src included-file)))
+            (unless (member ctime included-files-ctime)
+              ;; FIXME: The original code insisted on appending this ctime
+              ;; to the end of the list, even tho the order seems irrelevant.
+              (setq included-files-ctime
+                    (append included-files-ctime (list ctime)))))))
       (unless visiting (kill-buffer buf)))
     (if (null pstamp) t
       (let ((ctime (org-publish-cache-ctime-of-src filename)))
diff --git a/lisp/progmodes/ada-prj.el b/lisp/progmodes/ada-prj.el
index a49e5168b2e..f1b90875044 100644
--- a/lisp/progmodes/ada-prj.el
+++ b/lisp/progmodes/ada-prj.el
@@ -24,17 +24,13 @@
 
 ;;; Commentary:
 
-;;; This package provides a set of functions to easily edit the project
-;;; files used by the ada-mode.
-;;; The only function publicly available here is `ada-customize'.
-;;; See the documentation of the Ada mode for more information on the project
-;;; files.
-;;; Internally, a project file is represented as a property list, with each
-;;; field of the project file matching one property of the list.
-
-
-;;; History:
-;;
+;; This package provides a set of functions to easily edit the project
+;; files used by the ada-mode.
+;; The only function publicly available here is `ada-customize'.
+;; See the documentation of the Ada mode for more information on the project
+;; files.
+;; Internally, a project file is represented as a property list, with each
+;; field of the project file matching one property of the list.
 
 ;;; Code:
 
@@ -45,7 +41,8 @@
 (require 'ada-xref)
 
 (eval-when-compile
-   (require 'ada-mode))
+  (require 'ada-mode))
+(eval-when-compile (require 'cl-lib))
 
 ;; ----- Buffer local variables -------------------------------------------
 
@@ -125,7 +122,7 @@ If the current value of FIELD is the default value, return an empty string."
   (let ((file-name (or (plist-get ada-prj-current-values 'filename)
 		       (read-file-name "Save project as: ")))
 	output)
-    (set 'output
+    (setq output
 	 (concat
 
 	  ;;  Save the fields that do not depend on the current buffer
@@ -176,7 +173,7 @@ If the current value of FIELD is the default value, return an empty string."
     (kill-buffer "*Edit Ada Mode Project*")
 
     ;; automatically set the new project file as the active one
-    (set 'ada-prj-default-project-file file-name)
+    (setq ada-prj-default-project-file file-name)
 
     ;; force Emacs to reread the project files
     (ada-reread-prj-file file-name)
@@ -195,12 +192,12 @@ One item per line should be found in the file."
       (widen)
       (goto-char (point-min))
       (while (not (eobp))
-	(set 'line (buffer-substring-no-properties (point) (point-at-eol)))
-	(add-to-list 'list line)
+	(setq line (buffer-substring-no-properties (point) (point-at-eol)))
+	(cl-pushnew line list :test #'equal)
 	(forward-line 1))
       (kill-buffer nil)
       (set-buffer buffer)
-      (set 'ada-prj-current-values
+      (setq ada-prj-current-values
 	   (plist-put ada-prj-current-values
 		      symbol
 		      (append (plist-get ada-prj-current-values symbol)
@@ -215,8 +212,8 @@ One item per line should be found in the file."
       (if (file-directory-p (car subdirs))
 	  (let ((sub (ada-prj-subdirs-of (car subdirs))))
 	    (if sub
-		(set 'dirlist (append sub dirlist)))))
-      (set 'subdirs (cdr subdirs)))
+		(setq dirlist (append sub dirlist)))))
+      (setq subdirs (cdr subdirs)))
     dirlist))
 
 (defun ada-prj-load-directory (field &optional file-name)
@@ -227,9 +224,9 @@ If FILE-NAME is nil, ask the user for the name."
   ;;  the user to select a directory
   (let ((use-dialog-box nil))
     (unless file-name
-      (set 'file-name (read-directory-name "Root directory: " nil nil t))))
+      (setq file-name (read-directory-name "Root directory: " nil nil t))))
 
-  (set 'ada-prj-current-values
+  (setq ada-prj-current-values
        (plist-put ada-prj-current-values
 		  field
 		  (append (plist-get ada-prj-current-values field)
@@ -551,7 +548,7 @@ converted to a directory name."
 Remaining args DUMMY are ignored.
 Save the change in `ada-prj-current-values' so that selecting
 another page and coming back keeps the new value."
-  (set 'ada-prj-current-values
+  (setq ada-prj-current-values
        (plist-put ada-prj-current-values
 		  (widget-get widget ':prj-field)
 		  (widget-value widget))))
@@ -621,7 +618,7 @@ AFTER-TEXT is inserted just after the widget."
 	(inhibit-read-only t)
 	widget)
     (unless value
-      (set 'value
+      (setq value
 	   (if is-list  '() "")))
     (widget-insert text)
     (widget-insert ":")
@@ -649,7 +646,7 @@ AFTER-TEXT is inserted just after the widget."
 			 "Load Recursive Directory")
 	  (widget-insert "\n           ${build_dir}\n")))
 
-    (set 'widget
+    (setq widget
 	 (if is-list
 	     (if (< (length value) 15)
 		 (widget-create 'editable-list
diff --git a/lisp/progmodes/ada-xref.el b/lisp/progmodes/ada-xref.el
index 4da81da7854..4e196505b6c 100644
--- a/lisp/progmodes/ada-xref.el
+++ b/lisp/progmodes/ada-xref.el
@@ -25,19 +25,14 @@
 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
 
 ;;; Commentary:
-;;; This Package provides a set of functions to use the output of the
-;;; cross reference capabilities of the GNAT Ada compiler
-;;; for lookup and completion in Ada mode.
-;;;
-;;; If a file *.`adp' exists in the ada-file directory, then it is
-;;; read for configuration information.  It is read only the first
-;;; time a cross-reference is asked for, and is not read later.
 
-;;; You need Emacs >= 20.2 to run this package
-
-
-;;; History:
+;; This Package provides a set of functions to use the output of the
+;; cross reference capabilities of the GNAT Ada compiler
+;; for lookup and completion in Ada mode.
 ;;
+;; If a file *.`adp' exists in the ada-file directory, then it is
+;; read for configuration information.  It is read only the first
+;; time a cross-reference is asked for, and is not read later.
 
 ;;; Code:
 
@@ -47,6 +42,7 @@
 (require 'comint)
 (require 'find-file)
 (require 'ada-mode)
+(eval-when-compile (require 'cl-lib))
 
 ;; ------ User variables
 (defcustom ada-xref-other-buffer t
@@ -318,9 +314,9 @@ CROSS-PREFIX is the prefix to use for the `gnatls' command."
 		(forward-line 1)
 		(while (not (looking-at "^$"))
 		  (back-to-indentation)
-		  (if (looking-at "<Current_Directory>")
-		      (add-to-list 'ada-xref-runtime-library-specs-path  ".")
-		    (add-to-list 'ada-xref-runtime-library-specs-path
+		  (add-to-list 'ada-xref-runtime-library-specs-path
+                               (if (looking-at "<Current_Directory>")
+                                   "."
 				 (buffer-substring-no-properties
 				  (point)
 				  (point-at-eol))))
@@ -332,9 +328,9 @@ CROSS-PREFIX is the prefix to use for the `gnatls' command."
 		(forward-line 1)
 		(while (not (looking-at "^$"))
 		  (back-to-indentation)
-		  (if (looking-at "<Current_Directory>")
-		      (add-to-list 'ada-xref-runtime-library-ali-path ".")
-		    (add-to-list 'ada-xref-runtime-library-ali-path
+		  (add-to-list 'ada-xref-runtime-library-ali-path
+                               (if (looking-at "<Current_Directory>")
+                                   "."
 				 (buffer-substring-no-properties
 				  (point)
 				  (point-at-eol))))
@@ -380,12 +376,12 @@ Assumes environment variable ADA_PROJECT_PATH is set properly."
 	  (forward-line 1) ; first directory in list
 	  (while (not (looking-at "^$")) ; terminate on blank line
 	    (back-to-indentation) ; skip whitespace
-	    (add-to-list 'src-dir
-                         (if (looking-at "<Current_Directory>")
-                             default-directory
-			   (expand-file-name
-			    (buffer-substring-no-properties
-			     (point) (line-end-position)))))
+	    (cl-pushnew (if (looking-at "<Current_Directory>")
+                            default-directory
+                          (expand-file-name
+                           (buffer-substring-no-properties
+                            (point) (line-end-position))))
+                        src-dir :test #'equal)
 	    (forward-line 1))
 
 	  ;;  Object path
@@ -394,12 +390,12 @@ Assumes environment variable ADA_PROJECT_PATH is set properly."
 	  (forward-line 1)
 	  (while (not (looking-at "^$"))
 	    (back-to-indentation)
-	    (add-to-list 'obj-dir
-                         (if (looking-at "<Current_Directory>")
-                             default-directory
-			   (expand-file-name
-			    (buffer-substring-no-properties
-			     (point) (line-end-position)))))
+	    (cl-pushnew (if (looking-at "<Current_Directory>")
+                            default-directory
+                          (expand-file-name
+                           (buffer-substring-no-properties
+                            (point) (line-end-position))))
+                        obj-dir :test #'equal)
 	    (forward-line 1))
 
 	  ;; Set properties
@@ -831,9 +827,9 @@ Return new value of PROJECT."
 	   ;; FIXME: strip trailing spaces
 	   ;; variable name alphabetical order
 	   ((string= (match-string 1) "ada_project_path")
-	    (add-to-list 'ada_project_path
-			 (expand-file-name
-			  (substitute-in-file-name (match-string 2)))))
+	    (cl-pushnew (expand-file-name
+                         (substitute-in-file-name (match-string 2)))
+                        ada_project_path :test #'equal))
 
 	   ((string= (match-string 1) "build_dir")
 	    (setq project
@@ -841,40 +837,40 @@ Return new value of PROJECT."
 			    (file-name-as-directory (match-string 2)))))
 
 	   ((string= (match-string 1) "casing")
-	    (add-to-list 'casing
-			 (expand-file-name (substitute-in-file-name (match-string 2)))))
+	    (cl-pushnew (expand-file-name (substitute-in-file-name (match-string 2)))
+                        casing :test #'equal))
 
 	   ((string= (match-string 1) "check_cmd")
-	    (add-to-list 'check_cmd (match-string 2)))
+	    (cl-pushnew (match-string 2) check_cmd :test #'equal))
 
 	   ((string= (match-string 1) "comp_cmd")
-	    (add-to-list 'comp_cmd (match-string 2)))
+	    (cl-pushnew (match-string 2) comp_cmd :test #'equal))
 
 	   ((string= (match-string 1) "debug_post_cmd")
-	    (add-to-list 'debug_post_cmd (match-string 2)))
+	    (cl-pushnew (match-string 2) debug_post_cmd :test #'equal))
 
 	   ((string= (match-string 1) "debug_pre_cmd")
-	    (add-to-list 'debug_pre_cmd (match-string 2)))
+	    (cl-pushnew (match-string 2) debug_pre_cmd :test #'equal))
 
 	   ((string= (match-string 1) "gpr_file")
 	    ;; expand now; path is relative to Emacs project file
 	    (setq gpr_file (expand-file-name (match-string 2))))
 
 	   ((string= (match-string 1) "make_cmd")
-	    (add-to-list 'make_cmd (match-string 2)))
+	    (cl-pushnew (match-string 2) make_cmd :test #'equal))
 
 	   ((string= (match-string 1) "obj_dir")
-	    (add-to-list 'obj_dir
-			 (file-name-as-directory
-			  (expand-file-name (match-string 2)))))
+	    (cl-pushnew (file-name-as-directory
+                         (expand-file-name (match-string 2)))
+                        obj_dir :test #'equal))
 
 	   ((string= (match-string 1) "run_cmd")
-	    (add-to-list 'run_cmd (match-string 2)))
+	    (cl-pushnew (match-string 2) run_cmd :test #'equal))
 
 	   ((string= (match-string 1) "src_dir")
-	    (add-to-list 'src_dir
-			 (file-name-as-directory
-			  (expand-file-name (match-string 2)))))
+	    (cl-pushnew (file-name-as-directory
+                         (expand-file-name (match-string 2)))
+                        src_dir :test #'equal))
 
 	   (t
 	    ;; any other field in the file is just copied
@@ -1866,8 +1862,8 @@ This function is disabled for operators, and only works for identifiers."
 		)
 	      ;; construct a list with the file names and the positions within
 	      (if (re-search-backward "^X [0-9]+ \\([a-zA-Z0-9._-]+\\)" nil t)
-		  (add-to-list
-		   'declist (list line-ali (match-string 1) line-ada col-ada))
+		  (cl-pushnew (list line-ali (match-string 1) line-ada col-ada)
+                              declist :test #'equal)
 		)
 	      )
 	    )
diff --git a/lisp/progmodes/idlw-shell.el b/lisp/progmodes/idlw-shell.el
index 689c1ade8a2..1282f08b073 100644
--- a/lisp/progmodes/idlw-shell.el
+++ b/lisp/progmodes/idlw-shell.el
@@ -3597,7 +3597,7 @@ Existing overlays are recycled, in order to minimize consumption."
       (if ov-alist
 	  (while (setq ov-list (pop ov-alist))
 	    (while (setq ov (pop (cdr ov-list)))
-	      (add-to-list 'old-buffers (overlay-buffer ov))
+	      (pushnew (overlay-buffer ov) old-buffers)
 	      (delete-overlay ov))))
 
       (setq ov-alist idlwave-shell-bp-overlays