[elpa] externals/auctex b326502 05/23: Don't use `add-to-list' on lexical vars

[Tassilo Horn]

branch: externals/auctex
commit b326502954199d5f4339f09e82dfd1dcb32ca1d6
Author: Ikumi Keita <ikumi@ikumi.que.jp>
Commit: Ikumi Keita <ikumi@ikumi.que.jp>

    Don't use `add-to-list' on lexical vars
    
    * tex.el (TeX-view-program-list, TeX-view-program-selection):
    (TeX-add-to-alist):
    Don't use `add-to-list' on lexical scope variables.
    * tests/tex/utility.el (TeX-adding-to-alist): New test.
    (): Enable lexical binding.  Update copyright year.
---
 tests/tex/utility.el | 31 +++++++++++++++++++++++++++++--
 tex.el               | 14 ++++++++------
 2 files changed, 37 insertions(+), 8 deletions(-)

diff --git a/tests/tex/utility.el b/tests/tex/utility.el
index 92442ba..ac0a8aa 100644
--- a/tests/tex/utility.el
+++ b/tests/tex/utility.el
@@ -1,6 +1,6 @@
-;;; utility.el --- tests for AUCTeX utility functions
+;;; utility.el --- tests for AUCTeX utility functions -*- lexical-binding: t; 
-*-
 
-;; Copyright (C) 2017 Free Software Foundation, Inc.
+;; Copyright (C) 2017, 2021 Free Software Foundation, Inc.
 
 ;; This file is part of AUCTeX.
 
@@ -28,4 +28,31 @@
   (should (TeX-delete-duplicate-strings '("nil")))
   (should (TeX-delete-dups-by-car '(("nil" . 1)))))
 
+;; `TeX-add-to-alist' needs dynamic scope variable as its first
+;; argument.
+(defvar TeX-dummy-alist nil)
+
+(ert-deftest TeX-adding-to-alist ()
+  "Check whether `TeX-add-to-alist' works as expected."
+  (TeX-add-to-alist 'TeX-dummy-alist '((a 1)))
+  (should (equal TeX-dummy-alist '((a 1))))
+
+  (TeX-add-to-alist 'TeX-dummy-alist '((b 2 3)))
+  (should (equal TeX-dummy-alist '((a 1) (b 2 3))))
+
+  ;; Append new value(s) of the same key. The target cons is moved to
+  ;; the last of the alist.
+  (TeX-add-to-alist 'TeX-dummy-alist '((a 4)))
+  (should (equal TeX-dummy-alist '((b 2 3) (a 1 4))))
+
+  ;; Adding the same value again should not create duplicated
+  ;; elements.
+  (TeX-add-to-alist 'TeX-dummy-alist '((a 1)))
+  (should (equal TeX-dummy-alist '((b 2 3) (a 1 4))))
+
+  ;; A value which is the same as the key should be included in the
+  ;; result.
+  (TeX-add-to-alist 'TeX-dummy-alist '((a a)))
+  (should (equal TeX-dummy-alist '((b 2 3) (a 1 4 a)))))
+
 ;;; utility.el ends here
diff --git a/tex.el b/tex.el
index 8469dd0..915702f 100644
--- a/tex.el
+++ b/tex.el
@@ -1365,7 +1365,7 @@ restarting Emacs."
                      ,(let (list)
                         ;; Build the list of available predicates.
                         (mapc (lambda (spec)
-                                (add-to-list 'list `(const ,(car spec))))
+                                (cl-pushnew `(const ,(car spec)) list :test 
#'equal))
                               (append TeX-view-predicate-list
                                       TeX-view-predicate-list-builtin))
                         ;; Sort the list alphabetically.
@@ -1421,7 +1421,7 @@ are evaluated positively is chosen."
                 ;; Offer list of defined predicates.
                 ,(let (list)
                    (mapc (lambda (spec)
-                           (add-to-list 'list `(const ,(car spec))))
+                           (cl-pushnew `(const ,(car spec)) list :test 
#'equal))
                          (append TeX-view-predicate-list
                                  TeX-view-predicate-list-builtin))
                    (setq list (sort list
@@ -1437,8 +1437,8 @@ are evaluated positively is chosen."
                 (group (choice :tag "Viewer"
                                ,@(let (list)
                                    (mapc (lambda (spec)
-                                           (add-to-list 'list
-                                                        `(const ,(car spec))))
+                                           (cl-pushnew `(const ,(car spec))
+                                                       list :test #'equal))
                                          (append TeX-view-program-list
                                                  
TeX-view-program-list-builtin))
                                    (sort list
@@ -4713,9 +4713,11 @@ element to ALIST-VAR."
             (set alist-var (delete old-element (symbol-value alist-var)))
             ;; Append to `old-element' the values of the current element of
             ;; NEW-ALIST.
-            (mapc (lambda (elt) (add-to-list 'old-element elt t))
+            (mapc (lambda (elt)
+                    (unless (member elt (cdr old-element))
+                      (setq old-element (append old-element (list elt)))))
                   (cdr new-element))
-            (set alist-var (add-to-list alist-var old-element t)))
+            (add-to-list alist-var old-element t))
         (add-to-list alist-var new-element t)))
     ;; Next element of NEW-ALIST.
     (setq new-alist (cdr new-alist))))