Don’t attempt to modify constant conses

From a patch privately suggested by Mattias Engdegård on 2020-05-11
in a followup to Bug#40671.
* admin/charsets/cp51932.awk:
* admin/charsets/eucjp-ms.awk:
Generate code that does not modify constant conses.
* doc/misc/emacs-mime.texi (Encoding Customization):
* lisp/emacs-lisp/byte-opt.el (byte-compile-side-effect-free-ops):
* lisp/frameset.el (frameset-persistent-filter-alist):
* lisp/gnus/gnus-sum.el (gnus-article-mode-line-format-alist):
Use append instead of nconc.
* lisp/language/japanese.el (japanese-ucs-cp932-to-jis-map)
(jisx0213-to-unicode):
Use mapcar instead of mapc.
* lisp/language/lao-util.el (lao-transcription-consonant-alist)
(lao-transcription-vowel-alist):
* lisp/language/tibetan.el (tibetan-subjoined-transcription-alist):
Use copy-sequence.
* test/src/fns-tests.el (fns-tests-nreverse):
(fns-tests-sort, fns-tests-collate-sort)
(fns-tests-string-version-lessp, fns-tests-mapcan):
Use copy-sequence, vector, and list.

2 files changed, 15 insertions, 12 deletions

diff --git a/admin/charsets/cp51932.awk b/admin/charsets/cp51932.awk
index 6aac98815b5..c3555095249 100644
--- a/admin/charsets/cp51932.awk
+++ b/admin/charsets/cp51932.awk
@@ -43,13 +43,14 @@ BEGIN {
 
 END {
   print ")))";
-  print "  (mapc #'(lambda (x)";
-  print "           (setcar x (decode-char 'japanese-jisx0208 (car x))))";
-  print "       map)";
+  print "  (setq map (mapcar (lambda (x)";
+  print "                     (cons (decode-char 'japanese-jisx0208 (car x))";
+  print "                           (cdr x)))";
+  print "                   map))";
   print "  (define-translation-table 'cp51932-decode map)";
-  print "  (mapc #'(lambda (x)";
-  print "           (let ((tmp (car x)))";
-  print "             (setcar x (cdr x)) (setcdr x tmp)))";
+  print "  (mapc (lambda (x)";
+  print "         (let ((tmp (car x)))";
+  print "           (setcar x (cdr x)) (setcdr x tmp)))";
   print "       map)";
   print "  (define-translation-table 'cp51932-encode map))";
   print "";
diff --git a/admin/charsets/eucjp-ms.awk b/admin/charsets/eucjp-ms.awk
index 0c9f94d0f48..f6a6748ce51 100644
--- a/admin/charsets/eucjp-ms.awk
+++ b/admin/charsets/eucjp-ms.awk
@@ -93,15 +93,17 @@ function write_entry (unicode) {
 
 END {
   print ")))";
-  print "  (mapc #'(lambda (x)";
+  print "  (setq map";
+  print "    (mapcar";
+  print "       (lambda (x)";
   print "           (let ((code (logand (car x) #x7F7F)))";
   print "             (if (integerp (cdr x))";
-  print "                 (setcar x (decode-char 'japanese-jisx0208 code))";
-  print "               (setcar x (decode-char 'japanese-jisx0212 code))";
-  print "               (setcdr x (cadr x)))))";
-  print "       map)";
+  print "                 (cons (decode-char 'japanese-jisx0208 code) (cdr x))";
+  print "               (cons (decode-char 'japanese-jisx0212 code)"
+  print "                     (cadr x)))))";
+  print "       map))";
   print "  (define-translation-table 'eucjp-ms-decode map)";
-  print "  (mapc #'(lambda (x)";
+  print "  (mapc (lambda (x)";
   print "           (let ((tmp (car x)))";
   print "             (setcar x (cdr x)) (setcdr x tmp)))";
   print "       map)";