Don’t attempt to modify constant strings

* lisp/bookmark.el (bookmark-bmenu-set-header):
Use copy-sequence instead of concat, for clarity.
Also, the byte-compiler optimizes (concat "a" "b") into "ab".
* lisp/button.el (make-text-button):
* test/lisp/erc/erc-track-tests.el (erc-track--erc-faces-in):
* test/lisp/password-cache-tests.el:
(password-cache-tests-add-and-remove)
(password-cache-tests-read-from-cache)
(password-cache-tests-in-cache-p, password-cache-tests-read)
(password-cache-tests-reset)
(password-cache-tests-add/expires-key)
(password-cache-tests-no-password-cache):
Don’t attempt to modify constant strings.
* lisp/progmodes/elisp-mode.el (elisp--xref-format)
(elisp--xref-format-extra):
Don’t attempt to modify constant strings via put-text-property.
* test/lisp/emacs-lisp/cl-macs-tests.el (cl-macs-loop-across-ref):
Don’t attempt to modify constant vectors or strings.

4 files changed, 9 insertions, 11 deletions

diff --git a/lisp/bookmark.el b/lisp/bookmark.el
index 0fa77ed3224..5bb16981711 100644
--- a/lisp/bookmark.el
+++ b/lisp/bookmark.el
@@ -1723,7 +1723,7 @@ deletion, or > if it is flagged for displaying."
 ;; according to `bookmark-bookmarks-timestamp'.
 (defun bookmark-bmenu-set-header ()
   "Set the immutable header line."
-  (let ((header (concat "%% " "Bookmark")))
+  (let ((header (copy-sequence "%% Bookmark")))
     (when bookmark-bmenu-toggle-filenames
       (setq header (concat header
                            (make-string (- bookmark-bmenu-file-column
diff --git a/lisp/button.el b/lisp/button.el
index 3a6a6de774c..f969a03cb02 100644
--- a/lisp/button.el
+++ b/lisp/button.el
@@ -349,7 +349,7 @@ Also see `insert-text-button'."
          (or (plist-member properties 'type)
              (plist-member properties :type))))
     (when (stringp beg)
-      (setq object beg beg 0 end (length object)))
+      (setq object (copy-sequence beg) beg 0 end (length object)))
     ;; Disallow setting the `category' property directly.
     (when (plist-get properties 'category)
       (error "Button `category' property may not be set directly"))
diff --git a/lisp/password-cache.el b/lisp/password-cache.el
index 5e5f3240bc3..86d802f283c 100644
--- a/lisp/password-cache.el
+++ b/lisp/password-cache.el
@@ -31,7 +31,7 @@
 ;; ;; Minibuffer prompt for password.
 ;;  => "foo"
 ;;
-;; (password-cache-add "test" "foo")
+;; (password-cache-add "test" (copy-sequence "foo"))
 ;;  => nil
 
 ;; (password-read "Password? " "test")
diff --git a/lisp/progmodes/elisp-mode.el b/lisp/progmodes/elisp-mode.el
index b737134f90c..d37eb8c152d 100644
--- a/lisp/progmodes/elisp-mode.el
+++ b/lisp/progmodes/elisp-mode.el
@@ -655,18 +655,16 @@ functions are annotated with \"<f>\" via the
 ;; WORKAROUND: This is nominally a constant, but the text properties
 ;; are not preserved thru dump if use defconst.  See bug#21237.
 (defvar elisp--xref-format
-  (let ((str "(%s %s)"))
-    (put-text-property 1 3 'face 'font-lock-keyword-face str)
-    (put-text-property 4 6 'face 'font-lock-function-name-face str)
-    str))
+  #("(%s %s)"
+    1 3 (face font-lock-keyword-face)
+    4 6 (face font-lock-function-name-face)))
 
 ;; WORKAROUND: This is nominally a constant, but the text properties
 ;; are not preserved thru dump if use defconst.  See bug#21237.
 (defvar elisp--xref-format-extra
-  (let ((str "(%s %s %s)"))
-    (put-text-property 1 3 'face 'font-lock-keyword-face str)
-    (put-text-property 4 6 'face 'font-lock-function-name-face str)
-    str))
+  #("(%s %s %s)"
+    1 3 (face font-lock-keyword-face)
+    4 6 (face font-lock-function-name-face)))
 
 (defvar find-feature-regexp);; in find-func.el