commit cdbbc2081ed2da3a641926e76341ed413fb5b9f9 (HEAD, refs/remotes/origin/master)
Author: Stefan Kangas <stefankangas@gmail.com>
Date:   Sat Aug 8 01:20:01 2020 +0200

    Use lexical-binding in saveplace.el and add tests
    
    * lisp/saveplace.el: Use lexical-binding.
    (save-place-to-alist): Doc fix.
    * test/lisp/saveplace-tests.el:
    * test/lisp/saveplace-resources/saveplace: New files.

diff --git a/lisp/saveplace.el b/lisp/saveplace.el
index 46738ab03d..d420bfb4e9 100644
--- a/lisp/saveplace.el
+++ b/lisp/saveplace.el
@@ -1,4 +1,4 @@
-;;; saveplace.el --- automatically save place in files
+;;; saveplace.el --- automatically save place in files  -*- lexical-binding:t -*-
 
 ;; Copyright (C) 1993-1994, 2001-2020 Free Software Foundation, Inc.
 
@@ -42,7 +42,6 @@
   "Automatically save place in files."
   :group 'data)
 
-
 (defvar save-place-alist nil
   "Alist of saved places to go back to when revisiting files.
 Each element looks like (FILENAME . POSITION);
@@ -175,10 +174,11 @@ file:
 (declare-function dired-get-filename "dired" (&optional localp no-error-if-not-filep))
 
 (defun save-place-to-alist ()
-  ;; put filename and point in a cons box and then cons that onto the
-  ;; front of the save-place-alist, if save-place-mode is non-nil.
-  ;; Otherwise, just delete that file from the alist.
-  ;; first check to make sure alist has been loaded in from the master
+  "Add current buffer filename and position to `save-place-alist'.
+Put filename and point in a cons box and then cons that onto the
+front of the `save-place-alist', if `save-place-mode' is non-nil.
+Otherwise, just delete that file from the alist."
+  ;; First check to make sure alist has been loaded in from the master
   ;; file.  If not, do so, then feel free to modify the alist.  It
   ;; will be saved again when Emacs is killed.
   (or save-place-loaded (load-save-place-alist-from-file))
diff --git a/test/lisp/saveplace-resources/saveplace b/test/lisp/saveplace-resources/saveplace
new file mode 100644
index 0000000000..3f3f6d501d
--- /dev/null
+++ b/test/lisp/saveplace-resources/saveplace
@@ -0,0 +1,4 @@
+;;; -*- coding: utf-8 -*-
+(("/home/skangas/.emacs.d/cache/recentf" . 1306)
+ ("/home/skangas/wip/emacs/"
+  (dired-filename . "/home/skangas/wip/emacs/COPYING")))
diff --git a/test/lisp/saveplace-tests.el b/test/lisp/saveplace-tests.el
new file mode 100644
index 0000000000..ae7749fe93
--- /dev/null
+++ b/test/lisp/saveplace-tests.el
@@ -0,0 +1,103 @@
+;;; saveplace-tests.el --- Tests for saveplace.el  -*- lexical-binding:t -*-
+
+;; Copyright (C) 2019-2020 Free Software Foundation, Inc.
+
+;; Author: Stefan Kangas <stefankangas@gmail.com>
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs is free software: you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; GNU Emacs is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+(require 'ert)
+(require 'saveplace)
+
+(defvar saveplace-tests-dir
+  (file-truename
+   (expand-file-name "saveplace-resources"
+                     (file-name-directory (or load-file-name
+                                              buffer-file-name)))))
+
+(ert-deftest saveplace-test-save-place-to-alist/dir ()
+  (save-place-mode)
+  (let* ((save-place-alist nil)
+         (save-place-loaded t)
+         (loc saveplace-tests-dir))
+    (save-window-excursion
+      (dired loc)
+      (save-place-to-alist)
+      (should (equal save-place-alist
+                     `((,(concat loc "/")
+                        (dired-filename . ,(concat loc "/saveplace")))))))))
+
+(ert-deftest saveplace-test-save-place-to-alist/file ()
+  (save-place-mode)
+  (let* ((tmpfile (make-temp-file "emacs-test-saveplace-"))
+         (save-place-alist nil)
+         (save-place-loaded t)
+         (loc tmpfile)
+         (pos 4))
+    (unwind-protect
+        (save-window-excursion
+          (find-file loc)
+          (insert "abc") ; must insert something
+          (save-place-to-alist)
+          (should (equal save-place-alist (list (cons tmpfile pos)))))
+      (delete-file tmpfile))))
+
+(ert-deftest saveplace-test-forget-unreadable-files ()
+  (save-place-mode)
+  (let* ((save-place-loaded t)
+         (tmpfile (make-temp-file "emacs-test-saveplace-"))
+         (alist-orig (list (cons "/this/file/does/not/exist" 10)
+                           (cons tmpfile 1917)))
+         (save-place-alist alist-orig))
+    (unwind-protect
+        (progn
+          (save-place-forget-unreadable-files)
+          (should (equal save-place-alist (cdr alist-orig))))
+      (delete-file tmpfile))))
+
+(ert-deftest saveplace-test-place-alist-to-file ()
+  (save-place-mode)
+  (let* ((tmpfile (make-temp-file "emacs-test-saveplace-"))
+         (tmpfile2 (make-temp-file "emacs-test-saveplace-"))
+         (save-place-file tmpfile)
+         (save-place-alist (list (cons tmpfile2 99))))
+    (unwind-protect
+        (progn (save-place-alist-to-file)
+               (setq save-place-alist nil)
+               (save-window-excursion
+                 (find-file save-place-file)
+                 (unwind-protect
+                     (should (string-match tmpfile2 (buffer-string)))
+                   (kill-buffer))))
+      (delete-file tmpfile)
+      (delete-file tmpfile2))))
+
+(ert-deftest saveplace-test-load-alist-from-file ()
+  (save-place-mode)
+  (let ((save-place-loaded nil)
+        (save-place-file
+         (expand-file-name "saveplace" saveplace-tests-dir))
+        (save-place-alist nil))
+    (load-save-place-alist-from-file)
+    (should (equal save-place-alist
+                   '(("/home/skangas/.emacs.d/cache/recentf" . 1306)
+                     ("/home/skangas/wip/emacs/"
+                      (dired-filename . "/home/skangas/wip/emacs/COPYING")))))))
+
+(provide 'saveplace-tests)
+;;; saveplace-tests.el ends here

commit 67ffffa66654236ded2cf121cb3139b07d2ac5c8
Author: Stefan Kangas <stefankangas@gmail.com>
Date:   Fri Aug 7 19:40:31 2020 +0200

    * lisp/scroll-lock.el: Use lexical-binding.

diff --git a/lisp/scroll-lock.el b/lisp/scroll-lock.el
index 3a6d9d3642..f20ea1bcc8 100644
--- a/lisp/scroll-lock.el
+++ b/lisp/scroll-lock.el
@@ -1,4 +1,4 @@
-;;; scroll-lock.el --- Scroll lock scrolling.
+;;; scroll-lock.el --- Scroll lock scrolling.  -*- lexical-binding:t -*-
 
 ;; Copyright (C) 2005-2020 Free Software Foundation, Inc.
 

commit 7196abecb5f5c3cc1282280d2d337b6a86761656
Author: Simen Heggestøyl <simenheg@gmail.com>
Date:   Tue Jun 16 21:32:58 2020 +0200

    Use lexical-binding in browse-url.el and add tests
    
    * lisp/net/browse-url.el: Turn on lexical-binding.
    (browse-url--mailto, browse-url--man, browse-url--browser): Use
    imperative form in docstrings.
    (browse-url-delete-temp-file): Turn comment into a proper docstring.
    
    * test/lisp/net/browse-url-tests.el: New file with tests for
    browse-url.el.

diff --git a/lisp/net/browse-url.el b/lisp/net/browse-url.el
index 7c2fde98cc..2b8d4d0ce6 100644
--- a/lisp/net/browse-url.el
+++ b/lisp/net/browse-url.el
@@ -1,4 +1,4 @@
-;;; browse-url.el --- pass a URL to a WWW browser
+;;; browse-url.el --- pass a URL to a WWW browser  -*- lexical-binding: t; -*-
 
 ;; Copyright (C) 1995-2020 Free Software Foundation, Inc.
 
@@ -587,7 +587,7 @@ process), or nil (we don't know)."
       kind)))
 
 (defun browse-url--mailto (url &rest args)
-  "Calls `browse-url-mailto-function' with URL and ARGS."
+  "Call `browse-url-mailto-function' with URL and ARGS."
   (funcall browse-url-mailto-function url args))
 
 (defun browse-url--browser-kind-mailto (url)
@@ -596,7 +596,7 @@ process), or nil (we don't know)."
               #'browse-url--browser-kind-mailto)
 
 (defun browse-url--man (url &rest args)
-  "Calls `browse-url-man-function' with URL and ARGS."
+  "Call `browse-url-man-function' with URL and ARGS."
   (funcall browse-url-man-function url args))
 
 (defun browse-url--browser-kind-man (url)
@@ -605,7 +605,7 @@ process), or nil (we don't know)."
               #'browse-url--browser-kind-man)
 
 (defun browse-url--browser (url &rest args)
-  "Calls `browse-url-browser-function' with URL and ARGS."
+  "Call `browse-url-browser-function' with URL and ARGS."
   (funcall browse-url-browser-function url args))
 
 (defun browse-url--browser-kind-browser (url)
@@ -819,8 +819,8 @@ narrowed."
       (browse-url-of-file file-name))))
 
 (defun browse-url-delete-temp-file (&optional temp-file-name)
-  ;; Delete browse-url-temp-file-name from the file system
-  ;; If optional arg TEMP-FILE-NAME is non-nil, delete it instead
+  "Delete `browse-url-temp-file-name' from the file system.
+If optional arg TEMP-FILE-NAME is non-nil, delete it instead."
   (let ((file-name (or temp-file-name browse-url-temp-file-name)))
     (if (and file-name (file-exists-p file-name))
 	(delete-file file-name))))
diff --git a/test/lisp/net/browse-url-tests.el b/test/lisp/net/browse-url-tests.el
new file mode 100644
index 0000000000..b2b27d2ae7
--- /dev/null
+++ b/test/lisp/net/browse-url-tests.el
@@ -0,0 +1,119 @@
+;;; browse-url-tests.el --- Tests for browse-url.el  -*- lexical-binding: t; -*-
+
+;; Copyright (C) 2020 Free Software Foundation, Inc.
+
+;; Author: Simen Heggestøyl <simenheg@gmail.com>
+;; Keywords:
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs is free software: you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; GNU Emacs is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;;
+
+;;; Code:
+
+(require 'browse-url)
+(require 'ert)
+
+(ert-deftest browse-url-tests-browser-kind ()
+  (should (eq (browse-url--browser-kind #'browse-url-w3 "gnu.org")
+              'internal))
+  (should
+   (eq (browse-url--browser-kind #'browse-url-firefox "gnu.org")
+       'external)))
+
+(ert-deftest browse-url-tests-non-html-file-url-p ()
+  (should (browse-url--non-html-file-url-p "file://foo.txt"))
+  (should-not (browse-url--non-html-file-url-p "file://foo.html")))
+
+(ert-deftest browse-url-tests-select-handler-mailto ()
+  (should (eq (browse-url-select-handler "mailto:foo@bar.org")
+              'browse-url--mailto))
+  (should (eq (browse-url-select-handler "mailto:foo@bar.org"
+                                         'internal)
+              'browse-url--mailto))
+  (should-not (browse-url-select-handler "mailto:foo@bar.org"
+                                         'external)))
+
+(ert-deftest browse-url-tests-select-handler-man ()
+  (should (eq (browse-url-select-handler "man:ls") 'browse-url--man))
+  (should (eq (browse-url-select-handler "man:ls" 'internal)
+              'browse-url--man))
+  (should-not (browse-url-select-handler "man:ls" 'external)))
+
+(ert-deftest browse-url-tests-select-handler-file ()
+  (should (eq (browse-url-select-handler "file://foo.txt")
+              'browse-url-emacs))
+  (should (eq (browse-url-select-handler "file://foo.txt" 'internal)
+              'browse-url-emacs))
+  (should-not (browse-url-select-handler "file://foo.txt" 'external)))
+
+(ert-deftest browse-url-tests-url-encode-chars ()
+  (should (equal (browse-url-url-encode-chars "foobar" "[ob]")
+                 "f%6F%6F%62ar")))
+
+(ert-deftest browse-url-tests-encode-url ()
+  (should (equal (browse-url-encode-url "") ""))
+  (should (equal (browse-url-encode-url "a b c") "a b c"))
+  (should (equal (browse-url-encode-url "\"a\" \"b\"")
+                 "\"a%22\"b\""))
+  (should (equal (browse-url-encode-url "(a) (b)") "(a%29(b)"))
+  (should (equal (browse-url-encode-url "a$ b$") "a%24b$")))
+
+(ert-deftest browse-url-tests-url-at-point ()
+  (with-temp-buffer
+    (insert "gnu.org")
+    (should (equal (browse-url-url-at-point) "http://gnu.org"))))
+
+(ert-deftest browse-url-tests-file-url ()
+  (should (equal (browse-url-file-url "/foo") "file:///foo"))
+  (should (equal (browse-url-file-url "/foo:") "ftp://foo/"))
+  (should (equal (browse-url-file-url "/ftp@foo:") "ftp://foo/"))
+  (should (equal (browse-url-file-url "/anonymous@foo:")
+                 "ftp://foo/")))
+
+(ert-deftest browse-url-tests-delete-temp-file ()
+  (let ((browse-url-temp-file-name
+         (make-temp-file "browse-url-tests-")))
+    (browse-url-delete-temp-file)
+    (should-not (file-exists-p browse-url-temp-file-name)))
+  (let ((file (make-temp-file "browse-url-tests-")))
+    (browse-url-delete-temp-file file)
+    (should-not (file-exists-p file))))
+
+(ert-deftest browse-url-tests-add-buttons ()
+  (with-temp-buffer
+    (insert "Visit https://gnu.org")
+    (goto-char (point-min))
+    (browse-url-add-buttons)
+    (goto-char (- (point-max) 1))
+    (should (eq (get-text-property (point) 'face)
+                'browse-url-button))
+    (should (get-text-property (point) 'browse-url-data))))
+
+(ert-deftest browse-url-tests-button-copy ()
+  (with-temp-buffer
+    (insert "Visit https://gnu.org")
+    (goto-char (point-min))
+    (browse-url-add-buttons)
+    (should-error (browse-url-button-copy))
+    (goto-char (- (point-max) 1))
+    (browse-url-button-copy)
+    (should (equal (car kill-ring) "https://gnu.org"))))
+
+(provide 'browse-url-tests)
+;;; browse-url-tests.el ends here

commit 3e39aa6cfa6822b535d597b3e59abfea38610a48
Author: Stefan Kangas <stefankangas@gmail.com>
Date:   Fri Aug 7 14:42:41 2020 +0200

    Remove support for Mosaic from browse-url
    
    * lisp/net/browse-url.el (browse-url-mosaic-program)
    (browse-url-mosaic-arguments, browse-url-mosaic-pidfile)
    (browse-url-CCI-port, browse-url-CCI-host)
    (browse-url-default-browser, browse-url-mosaic, browse-url-cci):
    Remove support for the Mosaic browser, which saw its last release in
    1997, or 23 years ago.
    
    * etc/NEWS: Announce its removal.

diff --git a/etc/NEWS b/etc/NEWS
index dcd8ea6a9b..850b166069 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -547,6 +547,9 @@ either an internal or external browser.
 
 *** Support for the conkeror browser is now obsolete.
 
+*** Support for the Mosaic browser has been removed.
+This support has been obsolete since 25.1.
+
 ** SHR
 
 ---
diff --git a/lisp/net/browse-url.el b/lisp/net/browse-url.el
index 8892e800cd..7c2fde98cc 100644
--- a/lisp/net/browse-url.el
+++ b/lisp/net/browse-url.el
@@ -425,25 +425,6 @@ Passing an interactive argument to \\[browse-url], or specific browser
 commands reverses the effect of this variable."
   :type 'boolean)
 
-(defcustom browse-url-mosaic-program "xmosaic"
-  "The name by which to invoke Mosaic (or mMosaic)."
-  :type 'string
-  :version "20.3")
-
-(make-obsolete-variable 'browse-url-mosaic-program nil "25.1")
-
-(defcustom browse-url-mosaic-arguments nil
-  "A list of strings to pass to Mosaic as arguments."
-  :type '(repeat (string :tag "Argument")))
-
-(make-obsolete-variable 'browse-url-mosaic-arguments nil "25.1")
-
-(defcustom browse-url-mosaic-pidfile "~/.mosaicpid"
-  "The name of the pidfile created by Mosaic."
-  :type 'string)
-
-(make-obsolete-variable 'browse-url-mosaic-pidfile nil "25.1")
-
 (defcustom browse-url-conkeror-program "conkeror"
   "The name by which to invoke Conkeror."
   :type 'string
@@ -498,22 +479,6 @@ Used by the `browse-url-of-file' command."
   "Hook run after `browse-url-of-file' has asked a browser to load a file."
   :type 'hook)
 
-(defcustom browse-url-CCI-port 3003
-  "Port to access XMosaic via CCI.
-This can be any number between 1024 and 65535 but must correspond to
-the value set in the browser."
-  :type 'integer)
-
-(make-obsolete-variable 'browse-url-CCI-port nil "25.1")
-
-(defcustom browse-url-CCI-host "localhost"
-  "Host to access XMosaic via CCI.
-This should be the host name of the machine running XMosaic with CCI
-enabled.  The port number should be set in `browse-url-CCI-port'."
-  :type 'string)
-
-(make-obsolete-variable 'browse-url-CCI-host nil "25.1")
-
 (defvar browse-url-temp-file-name nil)
 (make-variable-buffer-local 'browse-url-temp-file-name)
 
@@ -1075,8 +1040,6 @@ instead of `browse-url-new-window-flag'."
 ;;;    ((executable-find browse-url-galeon-program) 'browse-url-galeon)
     ((executable-find browse-url-kde-program) 'browse-url-kde)
 ;;;    ((executable-find browse-url-netscape-program) 'browse-url-netscape)
-;;;    ((executable-find browse-url-mosaic-program) 'browse-url-mosaic)
-;;;    ((executable-find browse-url-conkeror-program) 'browse-url-conkeror)
     ((executable-find browse-url-chrome-program) 'browse-url-chrome)
     ((executable-find browse-url-xterm-program) 'browse-url-text-xterm)
     ((locate-library "w3") 'browse-url-w3)
@@ -1444,93 +1407,6 @@ used instead of `browse-url-new-window-flag'."
 
 (function-put 'browse-url-gnome-moz 'browse-url-browser-kind 'external)
 
-;; --- Mosaic ---
-
-;;;###autoload
-(defun browse-url-mosaic (url &optional new-window)
-  "Ask the XMosaic WWW browser to load URL.
-
-Default to the URL around or before point.  The strings in variable
-`browse-url-mosaic-arguments' are also passed to Mosaic and the
-program is invoked according to the variable
-`browse-url-mosaic-program'.
-
-When called interactively, if variable `browse-url-new-window-flag' is
-non-nil, load the document in a new Mosaic window, otherwise use a
-random existing one.  A non-nil interactive prefix argument reverses
-the effect of `browse-url-new-window-flag'.
-
-When called non-interactively, optional second argument NEW-WINDOW is
-used instead of `browse-url-new-window-flag'."
-  (declare (obsolete nil "25.1"))
-  (interactive (browse-url-interactive-arg "Mosaic URL: "))
-  (let ((pidfile (expand-file-name browse-url-mosaic-pidfile))
-	pid)
-    (if (file-readable-p pidfile)
-        (with-temp-buffer
-          (insert-file-contents pidfile)
-	  (setq pid (read (current-buffer)))))
-    (if (and (integerp pid) (zerop (signal-process pid 0))) ; Mosaic running
-        (progn
-          (with-temp-buffer
-            (insert (if (browse-url-maybe-new-window new-window)
-                        "newwin\n"
-                      "goto\n")
-                    url "\n")
-            (with-file-modes ?\700
-              (if (file-exists-p
-                   (setq pidfile (format "/tmp/Mosaic.%d" pid)))
-                  (delete-file pidfile))
-              ;; https://debbugs.gnu.org/17428.  Use O_EXCL.
-              (write-region nil nil pidfile nil 'silent nil 'excl)))
-	  ;; Send signal SIGUSR to Mosaic
-	  (message "Signaling Mosaic...")
-	  (signal-process pid 'SIGUSR1)
-	  ;; Or you could try:
-	  ;; (call-process "kill" nil 0 nil "-USR1" (int-to-string pid))
-	  (message "Signaling Mosaic...done"))
-      ;; Mosaic not running - start it
-      (message "Starting %s..." browse-url-mosaic-program)
-      (apply 'start-process "xmosaic" nil browse-url-mosaic-program
-	     (append browse-url-mosaic-arguments (list url)))
-      (message "Starting %s...done" browse-url-mosaic-program))))
-
-(function-put 'browse-url-mosaic 'browse-url-browser-kind 'external)
-
-;; --- Mosaic using CCI ---
-
-;;;###autoload
-(defun browse-url-cci (url &optional new-window)
-  "Ask the XMosaic WWW browser to load URL.
-Default to the URL around or before point.
-
-This function only works for XMosaic version 2.5 or later.  You must
-select `CCI' from XMosaic's File menu, set the CCI Port Address to the
-value of variable `browse-url-CCI-port', and enable `Accept requests'.
-
-When called interactively, if variable `browse-url-new-window-flag' is
-non-nil, load the document in a new browser window, otherwise use a
-random existing one.  A non-nil interactive prefix argument reverses
-the effect of `browse-url-new-window-flag'.
-
-When called non-interactively, optional second argument NEW-WINDOW is
-used instead of `browse-url-new-window-flag'."
-  (declare (obsolete nil "25.1"))
-  (interactive (browse-url-interactive-arg "Mosaic URL: "))
-  (open-network-stream "browse-url" " *browse-url*"
-		       browse-url-CCI-host browse-url-CCI-port)
-  ;; Todo: start browser if fails
-  (process-send-string "browse-url"
-		       (concat "get url (" url ") output "
-			       (if (browse-url-maybe-new-window new-window)
-				   "new"
-				 "current")
-			       "\r\n"))
-  (process-send-string "browse-url" "disconnect\r\n")
-  (delete-process "browse-url"))
-
-(function-put 'browse-url-cci 'browse-url-browser-kind 'external)
-
 ;; --- Conkeror ---
 ;;;###autoload
 (defun browse-url-conkeror (url &optional new-window)

commit d0ad6306727067936c9c8717dfc4e3aae5774902
Author: Lars Ingebrigtsen <larsi@gnus.org>
Date:   Fri Aug 7 14:07:14 2020 +0200

    Fix fontification of %d in strings in cperl-mode
    
    * lisp/progmodes/cperl-mode.el (cperl-init-faces): Don't fontify
    directives like %d in strings as hashes (bug#22867).

diff --git a/lisp/progmodes/cperl-mode.el b/lisp/progmodes/cperl-mode.el
index 5ecd5668b3..6122caf518 100644
--- a/lisp/progmodes/cperl-mode.el
+++ b/lisp/progmodes/cperl-mode.el
@@ -5753,7 +5753,7 @@ indentation and initial hashes.  Behaves usually outside of comment."
 	      (if (eq (char-after (match-beginning 2)) ?%)
 		  'cperl-hash-face
 		'cperl-array-face)
-	      t)			; arrays and hashes
+	      nil)			; arrays and hashes
 	     ("\\(\\([$@]+\\)[a-zA-Z_:][a-zA-Z0-9_:]*\\)[ \t]*\\([[{]\\)"
 	      1
 	      (if (= (- (match-end 2) (match-beginning 2)) 1)

commit 7ed61d6193629fa88d348221db3f1df7130a8bd3
Author: Stefan Kangas <stefankangas@gmail.com>
Date:   Fri Aug 7 13:54:50 2020 +0200

    Make more erc function aliases obsolete
    
    * lisp/erc/erc-compat.el (erc-propertize, erc-view-mode-enter)
    (erc-function-arglist, erc-delete-dups)
    (erc-replace-regexp-in-string): Make these aliases obsolete.
    
    * lisp/erc/erc-capab.el (erc-capab-identify-add-prefix)
    (erc-capab-identify-remove/set-identified-flag):
    * lisp/erc/erc-dcc.el (erc-dcc-chat-parse-output)
    (erc-dcc-unquote-filename, pcomplete/erc-mode/DCC):
    * lisp/erc/erc-list.el (erc-list-menu-mode, erc-list-button)
    (erc-list-make-string):
    * lisp/erc/erc-log.el (erc-log-standardize-name):
    * lisp/erc/erc-match.el (erc-log-matches-make-buffer):
    * lisp/erc/erc-networks.el (erc-server-select):
    * lisp/erc/erc.el (erc-message-english-PART)
    (erc-update-mode-line-buffer, erc-format-my-nick)
    (erc-format-@nick, erc-get-user-mode-prefix, erc-display-prompt)
    (erc-part-reason-zippy, erc-quit-reason-zippy, erc-get-arglist)
    (erc-toggle-debug-irc-protocol, erc-log-irc-protocol)
    (erc-migrate-modules): Adjust callers.

diff --git a/lisp/erc/erc-capab.el b/lisp/erc/erc-capab.el
index fc45725f78..4afe6a7614 100644
--- a/lisp/erc/erc-capab.el
+++ b/lisp/erc/erc-capab.el
@@ -170,11 +170,11 @@ PARSED is an `erc-parsed' response struct."
                (string-match "^\\([-\\+]\\)\\(.+\\)$" msg))
       (setf (erc-response.contents parsed)
             (if erc-capab-identify-mode
-                (erc-propertize (match-string 2 msg)
-                                'erc-identified
-                                (if (string= (match-string 1 msg) "+")
-                                    1
-                                  0))
+                (propertize (match-string 2 msg)
+                            'erc-identified
+                            (if (string= (match-string 1 msg) "+")
+                                1
+                              0))
               (match-string 2 msg)))
       nil)))
 
@@ -190,9 +190,9 @@ PARSED is an `erc-parsed' response struct."
                  ;; assuming the first use of `nickname' is the sender's nick
                  (re-search-forward (regexp-quote nickname) nil t))
         (goto-char (match-beginning 0))
-        (insert (erc-propertize erc-capab-identify-prefix
-                                'font-lock-face
-                                'erc-capab-identify-unidentified))))))
+        (insert (propertize erc-capab-identify-prefix
+                            'font-lock-face
+                            'erc-capab-identify-unidentified))))))
 
 (defun erc-capab-identify-get-unidentified-nickname (parsed)
   "Return the nickname of the user if unidentified.
diff --git a/lisp/erc/erc-compat.el b/lisp/erc/erc-compat.el
index 388728b04a..d71221b267 100644
--- a/lisp/erc/erc-compat.el
+++ b/lisp/erc/erc-compat.el
@@ -43,12 +43,12 @@ Return the same string, if the encoding operation is trivial.
 See `erc-encoding-coding-alist'."
   (encode-coding-string s coding-system t))
 
-(defalias 'erc-propertize 'propertize)
-(defalias 'erc-view-mode-enter 'view-mode-enter)
+(define-obsolete-function-alias 'erc-propertize #'propertize "28.1")
+(define-obsolete-function-alias 'erc-view-mode-enter #'view-mode-enter "28.1")
 (autoload 'help-function-arglist "help-fns")
-(defalias 'erc-function-arglist 'help-function-arglist)
-(defalias 'erc-delete-dups 'delete-dups)
-(defalias 'erc-replace-regexp-in-string 'replace-regexp-in-string)
+(define-obsolete-function-alias 'erc-function-arglist #'help-function-arglist "28.1")
+(define-obsolete-function-alias 'erc-delete-dups #'delete-dups "28.1")
+(define-obsolete-function-alias 'erc-replace-regexp-in-string #'replace-regexp-in-string "28.1")
 
 (defun erc-set-write-file-functions (new-val)
   (set (make-local-variable 'write-file-functions) new-val))
diff --git a/lisp/erc/erc-dcc.el b/lisp/erc/erc-dcc.el
index 8ccceec459..bf98eb818f 100644
--- a/lisp/erc/erc-dcc.el
+++ b/lisp/erc/erc-dcc.el
@@ -423,7 +423,7 @@ where FOO is one of CLOSE, GET, SEND, LIST, CHAT, etc."
                      #'(lambda (elt)
                          (eq (plist-get elt :type) 'CHAT))
                      erc-dcc-list)))
-     ('close (erc-delete-dups
+     ('close (delete-dups
               (mapcar (lambda (elt) (symbol-name (plist-get elt :type)))
                       erc-dcc-list)))
      ('get (mapcar #'erc-dcc-nick
@@ -636,8 +636,8 @@ that subcommand."
 
 (define-inline erc-dcc-unquote-filename (filename)
   (inline-quote
-   (erc-replace-regexp-in-string "\\\\\\\\" "\\"
-                                 (erc-replace-regexp-in-string "\\\\\"" "\"" ,filename t t) t t)))
+   (replace-regexp-in-string "\\\\\\\\" "\\"
+                             (replace-regexp-in-string "\\\\\"" "\"" ,filename t t) t t)))
 
 (defun erc-dcc-handle-ctcp-send (proc query nick login host to)
   "This is called if a CTCP DCC SEND subcommand is sent to the client.
@@ -1193,8 +1193,8 @@ other client."
         (setq posn (match-end 0))
         (erc-display-message
          nil nil proc
-         'dcc-chat-privmsg ?n (erc-propertize erc-dcc-from 'font-lock-face
-                                              'erc-nick-default-face) ?m line))
+         'dcc-chat-privmsg ?n (propertize erc-dcc-from 'font-lock-face
+                                          'erc-nick-default-face) ?m line))
       (setq erc-dcc-unprocessed-output (substring str posn)))))
 
 (defun erc-dcc-chat-buffer-killed ()
diff --git a/lisp/erc/erc-list.el b/lisp/erc/erc-list.el
index 5faeabb721..036d7733ed 100644
--- a/lisp/erc/erc-list.el
+++ b/lisp/erc/erc-list.el
@@ -71,13 +71,13 @@
 (defun erc-list-make-string (channel users topic)
   (concat
    channel
-   (erc-propertize " "
-		   'display (list 'space :align-to erc-list-nusers-column)
-		   'face 'fixed-pitch)
+   (propertize " "
+	       'display (list 'space :align-to erc-list-nusers-column)
+	       'face 'fixed-pitch)
    users
-   (erc-propertize " "
-		   'display (list 'space :align-to erc-list-topic-column)
-		   'face 'fixed-pitch)
+   (propertize " "
+	       'display (list 'space :align-to erc-list-topic-column)
+	       'face 'fixed-pitch)
    topic))
 
 ;; Insert a record into the list buffer.
@@ -143,19 +143,19 @@
 
 ;; Helper function that makes a buttonized column header.
 (defun erc-list-button (title column)
-  (erc-propertize title
-		  'column-number column
-		  'help-echo "mouse-1: sort by column"
-		  'mouse-face 'header-line-highlight
-		  'keymap erc-list-menu-sort-button-map))
+  (propertize title
+	      'column-number column
+	      'help-echo "mouse-1: sort by column"
+	      'mouse-face 'header-line-highlight
+	      'keymap erc-list-menu-sort-button-map))
 
 (define-derived-mode erc-list-menu-mode special-mode "ERC-List"
   "Major mode for editing a list of irc channels."
   (setq header-line-format
 	(concat
-	 (erc-propertize " "
-			 'display '(space :align-to 0)
-			 'face 'fixed-pitch)
+	 (propertize " "
+		     'display '(space :align-to 0)
+		     'face 'fixed-pitch)
 	 (erc-list-make-string (erc-list-button "Channel" 1)
 			       (erc-list-button "# Users" 2)
 			       "Topic")))
diff --git a/lisp/erc/erc-log.el b/lisp/erc/erc-log.el
index 1bad6d16c8..e2c066da9b 100644
--- a/lisp/erc/erc-log.el
+++ b/lisp/erc/erc-log.el
@@ -334,7 +334,7 @@ This will not work with full paths, only names.
 
 Any unsafe characters in the name are replaced with \"!\".  The
 filename is downcased."
-  (downcase (erc-replace-regexp-in-string
+  (downcase (replace-regexp-in-string
 	     "[/\\]" "!" (convert-standard-filename filename))))
 
 (defun erc-current-logfile (&optional buffer)
diff --git a/lisp/erc/erc-match.el b/lisp/erc/erc-match.el
index 0e98f2bc61..6e87a183fc 100644
--- a/lisp/erc/erc-match.el
+++ b/lisp/erc/erc-match.el
@@ -577,9 +577,9 @@ See `erc-log-match-format'."
     (with-current-buffer buffer
       (unless buffer-already
 	(insert " == Type \"q\" to dismiss messages ==\n")
-	(erc-view-mode-enter nil (lambda (buffer)
-				   (when (y-or-n-p "Discard messages? ")
-				     (kill-buffer buffer)))))
+	(view-mode-enter nil (lambda (buffer)
+			       (when (y-or-n-p "Discard messages? ")
+				 (kill-buffer buffer)))))
       buffer)))
 
 (defun erc-log-matches-come-back (proc parsed)
diff --git a/lisp/erc/erc-networks.el b/lisp/erc/erc-networks.el
index 415fb53fee..8551cdd1de 100644
--- a/lisp/erc/erc-networks.el
+++ b/lisp/erc/erc-networks.el
@@ -812,7 +812,7 @@ As an example:
   (let* ((completion-ignore-case t)
 	 (net (intern
 	       (completing-read "Network: "
-				(erc-delete-dups
+				(delete-dups
 				 (mapcar (lambda (x)
 					   (list (symbol-name (nth 1 x))))
 					 erc-server-alist)))))
diff --git a/lisp/erc/erc.el b/lisp/erc/erc.el
index 62aa76d25c..404a4c0997 100644
--- a/lisp/erc/erc.el
+++ b/lisp/erc/erc.el
@@ -1863,7 +1863,7 @@ buffer rather than a server buffer.")
   ;; modify `transforms' to specify what needs to be changed
   ;; each item is in the format '(old . new)
   (let ((transforms '((pcomplete . completion))))
-    (erc-delete-dups
+    (delete-dups
      (mapcar (lambda (m) (or (cdr (assoc m transforms)) m))
              mods))))
 
@@ -2316,7 +2316,7 @@ and appears in face `erc-input-face' in the buffer."
                             (setq result (concat result network-name
                                                  " << " line "\n")))
                           result)
-                      (erc-propertize
+                      (propertize
                        (concat network-name " >> " string
                                (if (/= ?\n
                                        (aref string
@@ -2339,7 +2339,7 @@ If ARG is non-nil, show the *erc-protocol* buffer."
   (interactive "P")
   (let* ((buf (get-buffer-create "*erc-protocol*")))
     (with-current-buffer buf
-      (erc-view-mode-enter)
+      (view-mode-enter)
       (when (null (current-local-map))
         (let ((inhibit-read-only t))
           (insert (erc-make-notice "This buffer displays all IRC protocol traffic exchanged with each server.\n"))
@@ -2773,7 +2773,7 @@ See also `erc-server-send'."
 
 (defun erc-get-arglist (fun)
   "Return the argument list of a function without the parens."
-  (let ((arglist (format "%S" (erc-function-arglist fun))))
+  (let ((arglist (format "%S" (help-function-arglist fun))))
     (if (string-match "\\`(\\(.*\\))\\'" arglist)
         (match-string 1 arglist)
       arglist)))
@@ -3558,7 +3558,7 @@ If S is non-nil, it will be used as the quit reason."
 If S is non-nil, it will be used as the quit reason."
   (or s
       (if (fboundp 'yow)
-          (erc-replace-regexp-in-string "\n" "" (yow))
+          (replace-regexp-in-string "\n" "" (yow))
         (erc-quit/part-reason-default))))
 
 (make-obsolete 'erc-quit-reason-zippy "it will be removed." "24.4")
@@ -3585,7 +3585,7 @@ If S is non-nil, it will be used as the part reason."
 If S is non-nil, it will be used as the quit reason."
   (or s
       (if (fboundp 'yow)
-          (erc-replace-regexp-in-string "\n" "" (yow))
+          (replace-regexp-in-string "\n" "" (yow))
         (erc-quit/part-reason-default))))
 
 (make-obsolete 'erc-part-reason-zippy "it will be removed." "24.4")
@@ -4001,13 +4001,13 @@ If FACE is non-nil, it will be used to propertize the prompt.  If it is nil,
         ;; Do not extend the text properties when typing at the end
         ;; of the prompt, but stuff typed in front of the prompt
         ;; shall remain part of the prompt.
-        (setq prompt (erc-propertize prompt
-                                     'start-open t ; XEmacs
-                                     'rear-nonsticky t ; Emacs
-                                     'erc-prompt t
-                                     'field t
-                                     'front-sticky t
-                                     'read-only t))
+        (setq prompt (propertize prompt
+                                 'start-open t ; XEmacs
+                                 'rear-nonsticky t ; Emacs
+                                 'erc-prompt t
+                                 'field t
+                                 'front-sticky t
+                                 'read-only t))
         (erc-put-text-property 0 (1- (length prompt))
                                'font-lock-face (or face 'erc-prompt-face)
                                prompt)
@@ -4390,15 +4390,15 @@ See also `erc-format-nick-function'."
 (defun erc-get-user-mode-prefix (user)
   (when user
     (cond ((erc-channel-user-owner-p user)
-           (erc-propertize "~" 'help-echo "owner"))
+           (propertize "~" 'help-echo "owner"))
           ((erc-channel-user-admin-p user)
-           (erc-propertize "&" 'help-echo "admin"))
+           (propertize "&" 'help-echo "admin"))
           ((erc-channel-user-op-p user)
-           (erc-propertize "@" 'help-echo "operator"))
+           (propertize "@" 'help-echo "operator"))
           ((erc-channel-user-halfop-p user)
-           (erc-propertize "%" 'help-echo "half-op"))
+           (propertize "%" 'help-echo "half-op"))
           ((erc-channel-user-voice-p user)
-           (erc-propertize "+" 'help-echo "voice"))
+           (propertize "+" 'help-echo "voice"))
           (t ""))))
 
 (defun erc-format-@nick (&optional user _channel-data)
@@ -4409,7 +4409,7 @@ prefix.  Use CHANNEL-DATA to determine op and voice status.  See
 also `erc-format-nick-function'."
   (when user
     (let ((nick (erc-server-user-nickname user)))
-      (concat (erc-propertize
+      (concat (propertize
                (erc-get-user-mode-prefix nick)
                'font-lock-face 'erc-nick-prefix-face)
 	      nick))))
@@ -4422,12 +4422,12 @@ also `erc-format-nick-function'."
              (nick (erc-current-nick))
              (mode (erc-get-user-mode-prefix nick)))
         (concat
-         (erc-propertize open 'font-lock-face 'erc-default-face)
-         (erc-propertize mode 'font-lock-face 'erc-my-nick-prefix-face)
-         (erc-propertize nick 'font-lock-face 'erc-my-nick-face)
-         (erc-propertize close 'font-lock-face 'erc-default-face)))
+         (propertize open 'font-lock-face 'erc-default-face)
+         (propertize mode 'font-lock-face 'erc-my-nick-prefix-face)
+         (propertize nick 'font-lock-face 'erc-my-nick-face)
+         (propertize close 'font-lock-face 'erc-default-face)))
     (let ((prefix "> "))
-      (erc-propertize prefix 'font-lock-face 'erc-default-face))))
+      (propertize prefix 'font-lock-face 'erc-default-face))))
 
 (defun erc-echo-notice-in-default-buffer (s parsed buffer _sender)
   "Echos a private notice in the default buffer, namely the
@@ -6489,16 +6489,16 @@ if `erc-away' is non-nil."
                                     (fill-region (point-min) (point-max))
                                     (buffer-string))))
                    (setq header-line-format
-                         (erc-replace-regexp-in-string
+                         (replace-regexp-in-string
                           "%"
                           "%%"
                           (if face
-                              (erc-propertize header 'help-echo help-echo
-                                              'face face)
-                            (erc-propertize header 'help-echo help-echo))))))
+                              (propertize header 'help-echo help-echo
+                                          'face face)
+                            (propertize header 'help-echo help-echo))))))
                 (t (setq header-line-format
                          (if face
-                             (erc-propertize header 'face face)
+                             (propertize header 'face face)
                            header)))))))
     (force-mode-line-update)))
 
@@ -6765,7 +6765,7 @@ functions."
               nick user host channel
               (if (not (string= reason ""))
                   (format ": %s"
-                          (erc-replace-regexp-in-string "%" "%%" reason))
+                          (replace-regexp-in-string "%" "%%" reason))
                 "")))))
 
 

commit b44a5d849e2d29bf91abe9015105cc71da458b1f
Author: Stephen Leake <stephen_leake@stephe-leake.org>
Date:   Fri Aug 7 04:43:18 2020 -0700

    * lisp/files.el (auto-mode-alist): delete ada-mode; now in GNU ELPA only

diff --git a/lisp/files.el b/lisp/files.el
index 742fd78df1..1909669346 100644
--- a/lisp/files.el
+++ b/lisp/files.el
@@ -2683,8 +2683,6 @@ since only a single case-insensitive search through the alist is made."
      ("\\.p\\'" . pascal-mode)
      ("\\.pas\\'" . pascal-mode)
      ("\\.\\(dpr\\|DPR\\)\\'" . delphi-mode)
-     ("\\.ad[abs]\\'" . ada-mode)
-     ("\\.ad[bs]\\.dg\\'" . ada-mode)
      ("\\.\\([pP]\\([Llm]\\|erl\\|od\\)\\|al\\)\\'" . perl-mode)
      ("Imakefile\\'" . makefile-imake-mode)
      ("Makeppfile\\(?:\\.mk\\)?\\'" . makefile-makepp-mode) ; Put this before .mk

commit 1545f28a98e143f027bd9cf69a2f0d323ad49ed3
Author: Lars Ingebrigtsen <larsi@gnus.org>
Date:   Fri Aug 7 13:36:50 2020 +0200

    Add some documentation for widget-describe and button-describe
    
    * doc/emacs/help.texi (Key Help): Document button-describe and
    widget-describe.
    
    * lisp/button.el (push-button): Mention button-describe.
    
    * lisp/cus-edit.el (Custom-newline): Mention widget-describe (bug#139).

diff --git a/doc/emacs/help.texi b/doc/emacs/help.texi
index 167c32c4d2..06ad5a583d 100644
--- a/doc/emacs/help.texi
+++ b/doc/emacs/help.texi
@@ -220,6 +220,16 @@ documentation string of the command it runs.
 command is not on any key, that means you must use @kbd{M-x} to run
 it.  @kbd{C-h w} runs the command @code{where-is}.
 
+@findex button-describe
+@findex widget-describe
+  Some modes in Emacs use various buttons (@pxref{Buttons,,,elisp, The
+Emacs Lisp Reference Manual}) and widgets
+(@pxref{Introduction,,,widget, Emacs Widgets}) that can be clicked to
+perform some action.  To find out what function is ultimately invoked
+by these buttons, Emacs provides the @code{button-describe} and
+@code{widget-describe} commands, that should be run with point over
+the button.
+
 @node Name Help
 @section Help by Command or Variable Name
 
diff --git a/etc/NEWS b/etc/NEWS
index 201c0b58cd..dcd8ea6a9b 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -123,8 +123,8 @@ horizontal movements now stop at the edge of the board.
 setting the variable 'auto-save-visited-mode' buffer-locally to nil.
 
 ** New commands to describe buttons and widgets have been added.
-'describe-widget' (on a widget) will pop up a help buffer and give a
-description of the properties.  Likewise 'describe-button' does the
+'widget-describe' (on a widget) will pop up a help buffer and give a
+description of the properties.  Likewise 'button-describe' does the
 same for a button.
 
 
diff --git a/lisp/button.el b/lisp/button.el
index 941b9fe720..03ab59b109 100644
--- a/lisp/button.el
+++ b/lisp/button.el
@@ -464,8 +464,12 @@ see).
 POS defaults to point, except when `push-button' is invoked
 interactively as the result of a mouse-event, in which case, the
 mouse event is used.
+
 If there's no button at POS, do nothing and return nil, otherwise
-return t."
+return t.
+
+To get a description of what function will called when pushing a
+butting, use the `button-describe' command."
   (interactive
    (list (if (integerp last-command-event) (point) last-command-event)))
   (if (and (not (integerp pos)) (eventp pos))
diff --git a/lisp/cus-edit.el b/lisp/cus-edit.el
index 1942f25e89..16695967df 100644
--- a/lisp/cus-edit.el
+++ b/lisp/cus-edit.el
@@ -4841,7 +4841,10 @@ The format is suitable for use with `easy-menu-define'."
   (error "You can't edit this part of the Custom buffer"))
 
 (defun Custom-newline (pos &optional event)
-  "Invoke button at POS, or refuse to allow editing of Custom buffer."
+  "Invoke button at POS, or refuse to allow editing of Custom buffer.
+
+To see what function the widget will call, use the
+`widget-describe' command."
   (interactive "@d")
   (let ((button (get-char-property pos 'button)))
     ;; If there is no button at point, then use the one at the start

commit 95b60c84b3bbed262d0af75bc69d4df9cb2cd9eb
Author: Mauro Aranda <maurooaranda@gmail.com>
Date:   Fri Aug 7 13:14:41 2020 +0200

    Add new commands to describe buttons and widgets
    
    * lisp/help-fns.el (describe-widget-functions): New variable, used by
    describe-widget.
    (describe-widget): New command, to display information about a widget.
    * lisp/button.el (button-describe): New command, for describing a button.
    (button--describe): Helper function for button-describe.
    * lisp/wid-edit.el (widget-describe): New command, for describing a
    widget.
    (widget--resolve-parent-action): Helper function, to allow
    widget-describe to display more useful information (bug#139).

diff --git a/etc/NEWS b/etc/NEWS
index 7429d392e4..201c0b58cd 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -122,6 +122,11 @@ horizontal movements now stop at the edge of the board.
 ** Autosaving via 'auto-save-visited-mode' can now be inhibited by
 setting the variable 'auto-save-visited-mode' buffer-locally to nil.
 
+** New commands to describe buttons and widgets have been added.
+'describe-widget' (on a widget) will pop up a help buffer and give a
+description of the properties.  Likewise 'describe-button' does the
+same for a button.
+
 
 * Changes in Specialized Modes and Packages in Emacs 28.1
 
diff --git a/lisp/button.el b/lisp/button.el
index d9c36a0375..941b9fe720 100644
--- a/lisp/button.el
+++ b/lisp/button.el
@@ -555,6 +555,51 @@ Returns the button found."
   (interactive "p\nd\nd")
   (forward-button (- n) wrap display-message no-error))
 
+(defun button--describe (properties)
+  "Describe a button's PROPERTIES (an alist) in a *Help* buffer.
+This is a helper function for `button-describe', in order to be possible to
+use `help-setup-xref'.
+
+Each element of PROPERTIES should be of the form (PROPERTY . VALUE)."
+  (help-setup-xref (list #'button--describe properties)
+                   (called-interactively-p 'interactive))
+  (with-help-window (help-buffer)
+    (with-current-buffer (help-buffer)
+      (insert (format-message "This button's type is `%s'."
+                              (alist-get 'type properties)))
+      (dolist (prop '(action mouse-action))
+        (let ((name (symbol-name prop))
+              (val (alist-get prop properties)))
+          (when (functionp val)
+            (insert "\n\n"
+                    (propertize (capitalize name) 'face 'bold)
+                    "\nThe " name " of this button is")
+            (if (symbolp val)
+                (progn
+                  (insert (format-message " `%s',\nwhich is " val))
+                  (describe-function-1 val))
+              (insert "\n")
+              (princ val))))))))
+
+(defun button-describe (&optional button-or-pos)
+  "Display a buffer with information about the button at point.
+
+When called from Lisp, pass BUTTON-OR-POS as the button to describe, or a
+buffer position where a button is present.  If BUTTON-OR-POS is nil, the
+button at point is the button to describe."
+  (interactive "d")
+  (let* ((button (cond ((integer-or-marker-p button-or-pos)
+                        (button-at button-or-pos))
+                       ((null button-or-pos) (button-at (point)))
+                       ((overlayp button-or-pos) button-or-pos)))
+         (props (and button
+                     (mapcar (lambda (prop)
+                               (cons prop (button-get button prop)))
+                             '(type action mouse-action)))))
+    (when props
+      (button--describe props)
+      t)))
+
 (provide 'button)
 
 ;;; button.el ends here
diff --git a/lisp/help-fns.el b/lisp/help-fns.el
index b953647063..5a99103f6a 100644
--- a/lisp/help-fns.el
+++ b/lisp/help-fns.el
@@ -1769,6 +1769,50 @@ documentation for the major and minor modes of that buffer."
   ;; For the sake of IELM and maybe others
   nil)
 
+;; Widgets.
+
+(defvar describe-widget-functions
+  '(button-describe widget-describe)
+  "A list of functions for `describe-widget' to call.
+Each function should take one argument, a buffer position, and return
+non-nil if it described a widget at that position.")
+
+;;;###autoload
+(defun describe-widget (&optional pos)
+  "Display a buffer with information about a widget.
+You can use this command to describe buttons (e.g., the links in a *Help*
+buffer), editable fields of the customization buffers, etc.
+
+Interactively, click on a widget to describe it, or hit RET to describe the
+widget at point.
+
+When called from Lisp, POS may be a buffer position or a mouse position list.
+
+Calls each function of the list `describe-widget-functions' in turn, until
+one of them returns non-nil."
+  (interactive
+   (list
+    (let ((key
+           (read-key
+            "Click on a widget, or hit RET to describe the widget at point")))
+      (cond ((eq key ?\C-m) (point))
+            ((and (mouse-event-p key)
+                  (eq (event-basic-type key) 'mouse-1)
+                  (equal (event-modifiers key) '(click)))
+             (event-end key))
+            ((eq key ?\C-g) (signal 'quit nil))
+            (t (user-error "You didn't specify a widget"))))))
+  (let (buf)
+    ;; Allow describing a widget in a different window.
+    (when (posnp pos)
+      (setq buf (window-buffer (posn-window pos))
+            pos (posn-point pos)))
+    (with-current-buffer (or buf (current-buffer))
+      (unless (cl-some (lambda (fun) (when (fboundp fun) (funcall fun pos)))
+                       describe-widget-functions)
+        (message "No widget found at that position")))))
+
+
 ;;; Replacements for old lib-src/ programs.  Don't seem especially useful.
 
 ;; Replaces lib-src/digest-doc.c.
diff --git a/lisp/wid-edit.el b/lisp/wid-edit.el
index 284fd1d6cb..ea7e266e0d 100644
--- a/lisp/wid-edit.el
+++ b/lisp/wid-edit.el
@@ -577,6 +577,63 @@ respectively."
       (if (and widget (funcall function widget maparg))
 	  (setq overlays nil)))))
 
+(defun widget-describe (&optional widget-or-pos)
+  "Describe the widget at point.
+Displays a buffer with information about the widget (e.g., its actions) as well
+as a link to browse all the properties of the widget.
+
+This command resolves the indirection of widgets running the action of its
+parents, so the real action executed can be known.
+
+When called from Lisp, pass WIDGET-OR-POS as the widget to describe,
+or a buffer position where a widget is present.  If WIDGET-OR-POS is nil,
+the widget at point is the widget to describe."
+  (interactive "d")
+  (require 'wid-browse) ; The widget-browse widget.
+  (let ((widget (if (widgetp widget-or-pos)
+                    widget-or-pos
+                  (widget-at widget-or-pos)))
+        props)
+    (when widget
+      (help-setup-xref (list #'widget-describe widget)
+                       (called-interactively-p 'interactive))
+      (setq props (list (cons 'action (widget--resolve-parent-action widget))
+                        (cons 'mouse-down-action
+                              (widget-get widget :mouse-down-action))))
+      (with-help-window (help-buffer)
+        (with-current-buffer (help-buffer)
+          (widget-insert "This widget's type is ")
+          (widget-create 'widget-browse :format "%[%v%]\n%d"
+                         :doc (get (car widget) 'widget-documentation)
+                         :help-echo "Browse this widget's properties"
+                         widget)
+          (dolist (action '(action mouse-down-action))
+            (let ((name (symbol-name action))
+                  (val (alist-get action props)))
+              (when (functionp val)
+                (widget-insert "\n\n" (propertize (capitalize name) 'face 'bold)
+                               "'\nThe " name " of this widget is")
+                (if (symbolp val)
+                    (progn (widget-insert " ")
+                           (widget-create 'function-link :value val
+                                          :button-prefix "" :button-suffix ""
+                                          :help-echo "Describe this function"))
+                  (widget-insert "\n")
+                  (princ val)))))))
+      (widget-setup)
+      t)))
+
+(defun widget--resolve-parent-action (widget)
+  "Resolve the real action of WIDGET up its inheritance chain.
+Follow the WIDGET's parents, until its :action is no longer
+`widget-parent-action', and return its value."
+  (let ((action (widget-get widget :action))
+        (parent (widget-get widget :parent)))
+    (while (eq action 'widget-parent-action)
+      (setq parent (widget-get parent :parent)
+            action (widget-get parent :action)))
+    action))
+
 ;;; Images.
 
 (defcustom widget-image-directory (file-name-as-directory

commit c32d6b21b81bed54d9738816c9164157ab6165c3
Author: Eli Zaretskii <eliz@gnu.org>
Date:   Fri Aug 7 14:03:24 2020 +0300

    Fix documentation of 'missing-newline-at-eof'
    
    * doc/emacs/display.texi (Useless Whitespace):
    * etc/NEWS (missing-newline-at-eof): Improve wording and
    punctuation.

diff --git a/doc/emacs/display.texi b/doc/emacs/display.texi
index 5778d95b4d..75ef520d62 100644
--- a/doc/emacs/display.texi
+++ b/doc/emacs/display.texi
@@ -1335,7 +1335,7 @@ customize the variable @code{whitespace-line-column}.
 Highlight newlines.
 
 @item missing-newline-at-eof
-Highlight the final character in a buffer unless it's a newline
+Highlight the final character if the buffer doesn't end with a newline
 character.
 
 @item empty
diff --git a/etc/NEWS b/etc/NEWS
index 002a078f84..7429d392e4 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -459,10 +459,10 @@ The new default value is 2000000 (2 megabytes).
 ** Whitespace mode
 
 +++
-*** A new style has been added: 'missing-newline-at-eof'
-If present in 'whitespace-style' (and it is now by default), the final
-character in the buffer will be highlighted unless it's a newline
-character.
+*** New style 'missing-newline-at-eof'.
+If present in 'whitespace-style' (as it is by default), the final
+character in the buffer will be highlighted if the buffer doesn't end
+with a newline.
 
 ** Texinfo
 

commit 2e4c63664d75de46b21d8853f187fc1116cb8240
Author: Lars Ingebrigtsen <larsi@gnus.org>
Date:   Fri Aug 7 12:56:13 2020 +0200

    Buffer-menu-select doc string clarification
    
    * lisp/buff-menu.el (Buffer-menu-select): Document that it removed
    the marks (bug#6491).

diff --git a/lisp/buff-menu.el b/lisp/buff-menu.el
index 655a76a713..9fe0dbae38 100644
--- a/lisp/buff-menu.el
+++ b/lisp/buff-menu.el
@@ -488,8 +488,9 @@ Buffers marked with \\<Buffer-menu-mode-map>`\\[Buffer-menu-delete]' are deleted
 (defun Buffer-menu-select ()
   "Select this line's buffer; also, display buffers marked with `>'.
 You can mark buffers with the \\<Buffer-menu-mode-map>`\\[Buffer-menu-mark]' command.
+
 This command deletes and replaces all the previously existing windows
-in the selected frame."
+in the selected frame, and will remove any marks."
   (interactive)
   (let* ((this-buffer (Buffer-menu-buffer t))
 	 (menu-buffer (current-buffer))

commit 92a0667f6b4c71c12c61206b49c575b24ca991f8
Author: Eli Zaretskii <eliz@gnu.org>
Date:   Fri Aug 7 13:54:39 2020 +0300

    ; * lisp/arc-mode.el (archive-copy-file): Doc fix.

diff --git a/lisp/arc-mode.el b/lisp/arc-mode.el
index 97213ab9e1..ae85fc55ad 100644
--- a/lisp/arc-mode.el
+++ b/lisp/arc-mode.el
@@ -1041,7 +1041,9 @@ return nil.  Otherwise point is returned."
     next))
 
 (defun archive-copy-file (file new-name)
-  "Copy file under point to a different location."
+  "Copy FILE to a location specified by NEW-NAME.
+Interactively, FILE is the file at point, and the function prompts
+for NEW-NAME."
   (interactive
    (let ((name (archive--file-desc-ext-file-name (archive-get-descr))))
      (list name

commit 8c4fe522860e733778531167c7ed6532840f40d4
Author: Peder O. Klingenberg <peder@klingenberg.no>
Date:   Thu Aug 6 14:32:52 2020 +0200

    * lisp/play/snake.el (snake-null-map): Quit on `q'. (Bug#42731)

diff --git a/lisp/play/snake.el b/lisp/play/snake.el
index d7c0683a05..70d80c464f 100644
--- a/lisp/play/snake.el
+++ b/lisp/play/snake.el
@@ -192,6 +192,7 @@ and then start moving it leftwards.")
 (defvar snake-null-map
   (let ((map (make-sparse-keymap 'snake-null-map)))
     (define-key map "n"		'snake-start-game)
+    (define-key map "q"         'quit-window)
     map)
   "Keymap for finished Snake games.")
 

commit 9c34b50fa17565311d1868de6a6557d128ed9206
Author: Lars Ingebrigtsen <larsi@gnus.org>
Date:   Fri Aug 7 11:59:25 2020 +0200

    Add a new command to copy a file from zip files
    
    * lisp/arc-mode.el (archive-copy-file): New command, keystroke and
    menu bar entry (bug#26192).
    (archive-extract): Refactored out code from here...
    (archive--extract-file): ... to here for use in archive-copy-file.

diff --git a/etc/NEWS b/etc/NEWS
index 64b77feb11..002a078f84 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -175,6 +175,11 @@ and variables.
 'archive-hideshow-column'.  These let you control which columns are
 displayed and which are kept hidden.
 
+---
+*** New command bound to 'C': 'archive-copy-file'
+This command extracts the file under point and writes the data to a
+file.
+
 ** Emacs Lisp mode
 
 *** The mode-line now indicates whether we're using lexical or dynamic scoping.
diff --git a/lisp/arc-mode.el b/lisp/arc-mode.el
index 901f09302e..97213ab9e1 100644
--- a/lisp/arc-mode.el
+++ b/lisp/arc-mode.el
@@ -391,6 +391,7 @@ file.  Archive and member name will be added."
     (define-key map "e" 'archive-extract)
     (define-key map "f" 'archive-extract)
     (define-key map "\C-m" 'archive-extract)
+    (define-key map "C" 'archive-copy-file)
     (define-key map "m" 'archive-mark)
     (define-key map "n" 'archive-next-line)
     (define-key map "\C-n" 'archive-next-line)
@@ -430,6 +431,9 @@ file.  Archive and member name will be added."
     (define-key map [menu-bar immediate view]
       '(menu-item "View This File" archive-view
                   :help "Display file at cursor in View Mode"))
+    (define-key map [menu-bar immediate view]
+      '(menu-item "Copy This File" archive-copy-file
+                  :help "Copy file at cursor to another location"))
     (define-key map [menu-bar immediate display]
       '(menu-item "Display in Other Window" archive-display-other-window
                   :help "Display file at cursor in another window"))
@@ -1036,6 +1040,26 @@ return nil.  Otherwise point is returned."
       (archive-goto-file short))
     next))
 
+(defun archive-copy-file (file new-name)
+  "Copy file under point to a different location."
+  (interactive
+   (let ((name (archive--file-desc-ext-file-name (archive-get-descr))))
+     (list name
+           (read-file-name (format "Copy %s to: " name)))))
+  (when (file-directory-p new-name)
+    (setq new-name (expand-file-name file new-name)))
+  (when (and (file-exists-p new-name)
+             (not (yes-or-no-p (format "%s already exists; overwrite? "
+                                       new-name))))
+    (user-error "Not overwriting %s" new-name))
+  (let* ((descr (archive-get-descr))
+         (archive (buffer-file-name))
+         (extractor (archive-name "extract"))
+         (ename (archive--file-desc-ext-file-name descr)))
+    (with-temp-buffer
+      (archive--extract-file extractor archive ename)
+      (write-region (point-min) (point-max) new-name))))
+
 (defun archive-extract (&optional other-window-p event)
   "In archive mode, extract this entry of the archive into its own buffer."
   (interactive (list nil last-input-event))
@@ -1077,26 +1101,7 @@ return nil.  Otherwise point is returned."
           (setq archive-subfile-mode descr)
 	  (setq archive-file-name-coding-system file-name-coding)
 	  (if (and
-	       (null
-		(let (;; We may have to encode the file name argument for
-		      ;; external programs.
-		      (coding-system-for-write
-		       (and enable-multibyte-characters
-			    archive-file-name-coding-system))
-		      ;; We read an archive member by no-conversion at
-		      ;; first, then decode appropriately by calling
-		      ;; archive-set-buffer-as-visiting-file later.
-		      (coding-system-for-read 'no-conversion)
-		      ;; Avoid changing dir mtime by lock_file
-		      (create-lockfiles nil))
-		  (condition-case err
-		      (if (fboundp extractor)
-			  (funcall extractor archive ename)
-			(archive-*-extract archive ename
-					   (symbol-value extractor)))
-		    (error
-		     (ding (message "%s" (error-message-string err)))
-		     nil))))
+	       (null (archive--extract-file extractor archive ename))
 	       just-created)
 	      (progn
 		(set-buffer-modified-p nil)
@@ -1129,6 +1134,27 @@ return nil.  Otherwise point is returned."
            (other-window-p (switch-to-buffer-other-window buffer))
            (t (switch-to-buffer buffer))))))
 
+(defun archive--extract-file (extractor archive ename)
+  (let (;; We may have to encode the file name argument for
+	;; external programs.
+	(coding-system-for-write
+	 (and enable-multibyte-characters
+	      archive-file-name-coding-system))
+	;; We read an archive member by no-conversion at
+	;; first, then decode appropriately by calling
+	;; archive-set-buffer-as-visiting-file later.
+	(coding-system-for-read 'no-conversion)
+	;; Avoid changing dir mtime by lock_file
+	(create-lockfiles nil))
+    (condition-case err
+	(if (fboundp extractor)
+	    (funcall extractor archive ename)
+	  (archive-*-extract archive ename
+			     (symbol-value extractor)))
+      (error
+       (ding (message "%s" (error-message-string err)))
+       nil))))
+
 (defun archive-*-extract (archive name command)
   (let* ((default-directory (file-name-as-directory archive-tmpdir))
 	 (tmpfile (expand-file-name (file-name-nondirectory name)

commit 8a9b13be10fcb95481b177cf8c873fc41e0eb8dc
Author: Lars Ingebrigtsen <larsi@gnus.org>
Date:   Fri Aug 7 11:30:55 2020 +0200

    Allow ffap to do the right thing with 'https://gnu.org'
    
    * lisp/thingatpt.el (thing-at-point-bounds-of-url-at-point): Don't
    include trailing ' in the URL, because it's more likely to be a
    punctuation character (bug#29410).

diff --git a/lisp/thingatpt.el b/lisp/thingatpt.el
index 1a15df33e5..483a2c9bd8 100644
--- a/lisp/thingatpt.el
+++ b/lisp/thingatpt.el
@@ -334,7 +334,7 @@ the bounds of a possible ill-formed URI (one lacking a scheme)."
       ;; may contain parentheses but may not contain spaces (RFC3986).
       (let* ((allowed-chars "--:=&?$+@-Z_[:alpha:]~#,%;*()!'")
 	     (skip-before "^[0-9a-zA-Z]")
-	     (skip-after  ":;.,!?")
+	     (skip-after  ":;.,!?'")
 	     (pt (point))
 	     (beg (save-excursion
 		    (skip-chars-backward allowed-chars)

commit 0facaeec1a37481536b6cef13c88d9728c2ec29b
Author: Mattias Engdegård <mattiase@acm.org>
Date:   Mon Aug 3 16:29:06 2020 +0200

    Clean up and improve compilation of arithmetic (bug#42597)
    
    * lisp/emacs-lisp/byte-opt.el (byte-optimize-associative-math)
    (byte-optimize-min-max): Transform 3-arg min/max call into two 2-arg
    calls, which is faster.
    * lisp/emacs-lisp/bytecomp.el (byte-compile-associative): Rename to...
    (byte-compile-variadic-numeric): ...this function and simplify,
    fixing incorrect comments.  The 3-arg strength reduction is now
    always done in the optimisers and is no longer needed here.
    (byte-compile-min-max): New function.
    (byte-compile-minus): Simplify, remove incorrect comment, and use
    byte-compile-variadic-numeric.
    (byte-compile-quo): Simplify and fix comment.

diff --git a/lisp/emacs-lisp/byte-opt.el b/lisp/emacs-lisp/byte-opt.el
index 0d9c449b3b..4987596bf9 100644
--- a/lisp/emacs-lisp/byte-opt.el
+++ b/lisp/emacs-lisp/byte-opt.el
@@ -648,14 +648,23 @@
 	  (setq args (cons (car rest) args)))
       (setq rest (cdr rest)))
     (if (cdr constants)
-	(if args
-	    (list (car form)
-		  (apply (car form) constants)
-		  (if (cdr args)
-		      (cons (car form) (nreverse args))
-		      (car args)))
-	    (apply (car form) constants))
-	form)))
+        (let ((const (apply (car form) (nreverse constants))))
+	  (if args
+	      (append (list (car form) const)
+                      (nreverse args))
+	    const))
+      form)))
+
+(defun byte-optimize-min-max (form)
+  "Optimize `min' and `max'."
+  (let ((opt (byte-optimize-associative-math form)))
+    (if (and (consp opt) (memq (car opt) '(min max))
+             (= (length opt) 4))
+        ;; (OP x y z) -> (OP (OP x y) z), in order to use binary byte ops.
+        (list (car opt)
+              (list (car opt) (nth 1 opt) (nth 2 opt))
+              (nth 3 opt))
+      opt)))
 
 ;; Use OP to reduce any leading prefix of constant numbers in the list
 ;; (cons ACCUM ARGS) down to a single number, and return the
@@ -878,8 +887,8 @@
 (put '*   'byte-optimizer #'byte-optimize-multiply)
 (put '-   'byte-optimizer #'byte-optimize-minus)
 (put '/   'byte-optimizer #'byte-optimize-divide)
-(put 'max 'byte-optimizer #'byte-optimize-associative-math)
-(put 'min 'byte-optimizer #'byte-optimize-associative-math)
+(put 'max 'byte-optimizer #'byte-optimize-min-max)
+(put 'min 'byte-optimizer #'byte-optimize-min-max)
 
 (put '=   'byte-optimizer #'byte-optimize-binary-predicate)
 (put 'eq  'byte-optimizer #'byte-optimize-binary-predicate)
diff --git a/lisp/emacs-lisp/bytecomp.el b/lisp/emacs-lisp/bytecomp.el
index 8f76a3abb9..7ae8749ab4 100644
--- a/lisp/emacs-lisp/bytecomp.el
+++ b/lisp/emacs-lisp/bytecomp.el
@@ -3580,10 +3580,10 @@ If it is nil, then the handler is \"byte-compile-SYMBOL.\""
 (byte-defop-compiler (% byte-rem)	2)
 (byte-defop-compiler aset		3)
 
-(byte-defop-compiler max		byte-compile-associative)
-(byte-defop-compiler min		byte-compile-associative)
-(byte-defop-compiler (+ byte-plus)	byte-compile-associative)
-(byte-defop-compiler (* byte-mult)	byte-compile-associative)
+(byte-defop-compiler max		byte-compile-min-max)
+(byte-defop-compiler min		byte-compile-min-max)
+(byte-defop-compiler (+ byte-plus)	byte-compile-variadic-numeric)
+(byte-defop-compiler (* byte-mult)	byte-compile-variadic-numeric)
 
 ;;####(byte-defop-compiler move-to-column	1)
 (byte-defop-compiler-1 interactive byte-compile-noop)
@@ -3730,30 +3730,36 @@ discarding."
   (if byte-compile--for-effect (setq byte-compile--for-effect nil)
     (byte-compile-out 'byte-constant (nth 1 form))))
 
-;; Compile a function that accepts one or more args and is right-associative.
-;; We do it by left-associativity so that the operations
-;; are done in the same order as in interpreted code.
-;; We treat the one-arg case, as in (+ x), like (* x 1).
-;; in order to convert markers to numbers, and trigger expected errors.
-(defun byte-compile-associative (form)
+;; Compile a pure function that accepts zero or more numeric arguments
+;; and has an opcode for the binary case.
+;; Single-argument calls are assumed to be numeric identity and are
+;; compiled as (* x 1) in order to convert markers to numbers and
+;; trigger type errors.
+(defun byte-compile-variadic-numeric (form)
+  (pcase (length form)
+    (1
+     ;; No args: use the identity value for the operation.
+     (byte-compile-constant (eval form)))
+    (2
+     ;; One arg: compile (OP x) as (* x 1). This is identity for
+     ;; all numerical values including -0.0, infinities and NaNs.
+     (byte-compile-form (nth 1 form))
+     (byte-compile-constant 1)
+     (byte-compile-out (get '* 'byte-opcode) 0))
+    (3
+     (byte-compile-form (nth 1 form))
+     (byte-compile-form (nth 2 form))
+     (byte-compile-out (get (car form) 'byte-opcode) 0))
+    (_
+     ;; >2 args: compile as a single function call.
+     (byte-compile-normal-call form))))
+
+(defun byte-compile-min-max (form)
+  "Byte-compile calls to `min' or `max'."
   (if (cdr form)
-      (let ((opcode (get (car form) 'byte-opcode))
-	    args)
-	(if (and (< 3 (length form))
-		 (memq opcode (list (get '+ 'byte-opcode)
-				    (get '* 'byte-opcode))))
-	    ;; Don't use binary operations for > 2 operands, as that
-	    ;; may cause overflow/truncation in float operations.
-	    (byte-compile-normal-call form)
-	  (setq args (copy-sequence (cdr form)))
-	  (byte-compile-form (car args))
-	  (setq args (cdr args))
-	  (or args (setq args '(1)
-			 opcode (get '* 'byte-opcode)))
-	  (dolist (arg args)
-	    (byte-compile-form arg)
-	    (byte-compile-out opcode 0))))
-    (byte-compile-constant (eval form))))
+      (byte-compile-variadic-numeric form)
+    ;; No args: warn and emit code that raises an error when executed.
+    (byte-compile-normal-call form)))
 
 
 ;; more complicated compiler macros
@@ -3768,7 +3774,7 @@ discarding."
 (byte-defop-compiler indent-to)
 (byte-defop-compiler insert)
 (byte-defop-compiler-1 function byte-compile-function-form)
-(byte-defop-compiler-1 - byte-compile-minus)
+(byte-defop-compiler (- byte-diff) byte-compile-minus)
 (byte-defop-compiler (/ byte-quo) byte-compile-quo)
 (byte-defop-compiler nconc)
 
@@ -3835,30 +3841,17 @@ discarding."
 	  ((byte-compile-normal-call form)))))
 
 (defun byte-compile-minus (form)
-  (let ((len (length form)))
-    (cond
-     ((= 1 len) (byte-compile-constant 0))
-     ((= 2 len)
-      (byte-compile-form (cadr form))
-      (byte-compile-out 'byte-negate 0))
-     ((= 3 len)
-      (byte-compile-form (nth 1 form))
-      (byte-compile-form (nth 2 form))
-      (byte-compile-out 'byte-diff 0))
-     ;; Don't use binary operations for > 2 operands, as that may
-     ;; cause overflow/truncation in float operations.
-     (t (byte-compile-normal-call form)))))
+  (if (/= (length form) 2)
+      (byte-compile-variadic-numeric form)
+    (byte-compile-form (cadr form))
+    (byte-compile-out 'byte-negate 0)))
 
 (defun byte-compile-quo (form)
-  (let ((len (length form)))
-    (cond ((< len 2)
-	   (byte-compile-subr-wrong-args form "1 or more"))
-	  ((= len 3)
-	   (byte-compile-two-args form))
-	  (t
-	   ;; Don't use binary operations for > 2 operands, as that
-	   ;; may cause overflow/truncation in float operations.
-	   (byte-compile-normal-call form)))))
+  (if (= (length form) 3)
+      (byte-compile-two-args form)
+    ;; N-ary `/' is not the left-reduction of binary `/' because if any
+    ;; argument is a float, then everything is done in floating-point.
+    (byte-compile-normal-call form)))
 
 (defun byte-compile-nconc (form)
   (let ((len (length form)))

commit 204273c3b9f0a77459661790aa929f86067a9ab1
Author: Mattias Engdegård <mattiase@acm.org>
Date:   Mon Aug 3 15:29:41 2020 +0200

    Fix byte-compilation of (+ -0.0) (bug#42597)
    
    * lisp/emacs-lisp/bytecomp.el (byte-compile-associative):
    Translate numerical identity expressions, such as (+ x) and (* x),
    into (* x 1) since the previous translation (+ x 0) gets it wrong
    for x = -0.0.
    * test/lisp/emacs-lisp/bytecomp-tests.el
    (byte-opt-testsuite-arith-data): Add test cases.

diff --git a/lisp/emacs-lisp/bytecomp.el b/lisp/emacs-lisp/bytecomp.el
index 22e648e44b..8f76a3abb9 100644
--- a/lisp/emacs-lisp/bytecomp.el
+++ b/lisp/emacs-lisp/bytecomp.el
@@ -3733,7 +3733,7 @@ discarding."
 ;; Compile a function that accepts one or more args and is right-associative.
 ;; We do it by left-associativity so that the operations
 ;; are done in the same order as in interpreted code.
-;; We treat the one-arg case, as in (+ x), like (+ x 0).
+;; We treat the one-arg case, as in (+ x), like (* x 1).
 ;; in order to convert markers to numbers, and trigger expected errors.
 (defun byte-compile-associative (form)
   (if (cdr form)
@@ -3748,8 +3748,8 @@ discarding."
 	  (setq args (copy-sequence (cdr form)))
 	  (byte-compile-form (car args))
 	  (setq args (cdr args))
-	  (or args (setq args '(0)
-			 opcode (get '+ 'byte-opcode)))
+	  (or args (setq args '(1)
+			 opcode (get '* 'byte-opcode)))
 	  (dolist (arg args)
 	    (byte-compile-form arg)
 	    (byte-compile-out opcode 0))))
diff --git a/test/lisp/emacs-lisp/bytecomp-tests.el b/test/lisp/emacs-lisp/bytecomp-tests.el
index c235dd43fc..894914300a 100644
--- a/test/lisp/emacs-lisp/bytecomp-tests.el
+++ b/test/lisp/emacs-lisp/bytecomp-tests.el
@@ -47,6 +47,11 @@
     (let ((a 1.0))				   (/ 3 a 2))
     (let ((a most-positive-fixnum) (b 2.0))	   (* a 2 b))
     (let ((a 3) (b 2))				   (/ a b 1.0))
+    (let ((a -0.0)) (+ a))
+    (let ((a -0.0)) (- a))
+    (let ((a -0.0)) (* a))
+    (let ((a -0.0)) (min a))
+    (let ((a -0.0)) (max a))
     (/ 3 -1)
     (+ 4 3 2 1)
     (+ 4 3 2.0 1)