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.

3 files changed, 12 insertions, 10 deletions

diff --git a/test/lisp/emacs-lisp/cl-macs-tests.el b/test/lisp/emacs-lisp/cl-macs-tests.el
index 983e79ac57c..24bbad0cc6b 100644
--- a/test/lisp/emacs-lisp/cl-macs-tests.el
+++ b/test/lisp/emacs-lisp/cl-macs-tests.el
@@ -425,7 +425,9 @@ collection clause."
                  '(2 3 4 5 6))))
 
 (ert-deftest cl-macs-loop-across-ref ()
-  (should (equal (cl-loop with my-vec = ["one" "two" "three"]
+  (should (equal (cl-loop with my-vec = (vector (cl-copy-seq "one")
+                                                (cl-copy-seq "two")
+                                                (cl-copy-seq "three"))
                           for x across-ref my-vec
                           do (setf (aref x 0) (upcase (aref x 0)))
                           finally return my-vec)
diff --git a/test/lisp/erc/erc-track-tests.el b/test/lisp/erc/erc-track-tests.el
index 7e924c22347..457f08cb73c 100644
--- a/test/lisp/erc/erc-track-tests.el
+++ b/test/lisp/erc/erc-track-tests.el
@@ -107,8 +107,8 @@
 
 (ert-deftest erc-track--erc-faces-in ()
   "`erc-faces-in' should pick up both 'face and 'font-lock-face properties."
-  (let ((str0 "is bold")
-        (str1 "is bold"))
+  (let ((str0 (copy-sequence "is bold"))
+        (str1 (copy-sequence "is bold")))
     ;; Turn on Font Lock mode: this initialize `char-property-alias-alist'
     ;; to '((face font-lock-face)).  Note that `font-lock-mode' don't
     ;; turn on the mode if the test is run on batch mode or if the
diff --git a/test/lisp/password-cache-tests.el b/test/lisp/password-cache-tests.el
index 01f4358fc59..55ebbfce7fe 100644
--- a/test/lisp/password-cache-tests.el
+++ b/test/lisp/password-cache-tests.el
@@ -28,31 +28,31 @@
 
 (ert-deftest password-cache-tests-add-and-remove ()
   (let ((password-data (copy-hash-table password-data)))
-    (password-cache-add "foo" "bar")
+    (password-cache-add "foo" (copy-sequence "bar"))
     (should (eq (password-in-cache-p "foo") t))
     (password-cache-remove "foo")
     (should (not (password-in-cache-p "foo")))))
 
 (ert-deftest password-cache-tests-read-from-cache ()
   (let ((password-data (copy-hash-table password-data)))
-    (password-cache-add "foo" "bar")
+    (password-cache-add "foo" (copy-sequence "bar"))
     (should (equal (password-read-from-cache "foo") "bar"))
     (should (not (password-read-from-cache nil)))))
 
 (ert-deftest password-cache-tests-in-cache-p ()
   (let ((password-data (copy-hash-table password-data)))
-    (password-cache-add "foo" "bar")
+    (password-cache-add "foo" (copy-sequence "bar"))
     (should (password-in-cache-p "foo"))
     (should (not (password-read-from-cache nil)))))
 
 (ert-deftest password-cache-tests-read ()
   (let ((password-data (copy-hash-table password-data)))
-    (password-cache-add "foo" "bar")
+    (password-cache-add "foo" (copy-sequence "bar"))
     (should (equal (password-read nil "foo") "bar"))))
 
 (ert-deftest password-cache-tests-reset ()
   (let ((password-data (copy-hash-table password-data)))
-    (password-cache-add "foo" "bar")
+    (password-cache-add "foo" (copy-sequence "bar"))
     (password-reset)
     (should (not (password-in-cache-p "foo")))))
 
@@ -60,14 +60,14 @@
   :tags '(:expensive-test)
   (let ((password-data (copy-hash-table password-data))
         (password-cache-expiry 0.01))
-    (password-cache-add "foo" "bar")
+    (password-cache-add "foo" (copy-sequence "bar"))
     (sit-for 0.1)
     (should (not (password-in-cache-p "foo")))))
 
 (ert-deftest password-cache-tests-no-password-cache ()
   (let ((password-data (copy-hash-table password-data))
         (password-cache nil))
-    (password-cache-add "foo" "bar")
+    (password-cache-add "foo" (copy-sequence "bar"))
     (should (not (password-in-cache-p "foo")))
     (should (not (password-read-from-cache "foo")))))