Improve the optional translation of quotes

Fix several problems with the recently-added custom variable
help-quote-translation where the code would quote inconsistently
in help buffers.  Add support for quoting 'like this', which
is common in other GNU programs in ASCII environments.  Change
help-quote-translation to use more mnemonic values: values are now the
initial quoting char, e.g., (setq help-quote-translation ?`) gets the
traditional Emacs help-buffer quoting style `like this'.  Change the
default behavior of substitute-command-keys to match what's done in
set-locale-environment, i.e., quote ‘like this’ if displayable,
'like this' otherwise.
* doc/lispref/help.texi (Keys in Documentation): Document
new behavior of substitute-command-keys, and document
help-quote-translation.
* doc/lispref/tips.texi (Documentation Tips):
Mention the effect of help-quote-translation.
* etc/NEWS: Mention new behavior of substitute-command-keys,
and merge help-quote-translation news into it.
When talking about doc strings, mention new ways to type quotes.
* lisp/cedet/mode-local.el (overload-docstring-extension):
Revert my recent change to this function, which shouldn't be
needed as the result is a doc string.
* lisp/cedet/mode-local.el (mode-local-print-binding)
(mode-local-describe-bindings-2):
* lisp/cedet/srecode/srt-mode.el (srecode-macro-help):
* lisp/cus-theme.el (describe-theme-1):
* lisp/descr-text.el (describe-text-properties-1, describe-char):
* lisp/emacs-lisp/cl-generic.el (cl--generic-describe):
* lisp/emacs-lisp/eieio-opt.el (eieio-help-class)
(eieio-help-constructor):
* lisp/emacs-lisp/package.el (describe-package-1):
* lisp/faces.el (describe-face):
* lisp/help-fns.el (help-fns--key-bindings)
(help-fns--compiler-macro, help-fns--parent-mode)
(help-fns--obsolete, help-fns--interactive-only)
(describe-function-1, describe-variable):
* lisp/help.el (describe-mode):
Use substitute-command-keys to ensure a more-consistent quoting
style in help buffers.
* lisp/cus-start.el (standard):
Document new help-quote-translation behavior.
* lisp/emacs-lisp/lisp-mode.el (lisp-fdefs):
* lisp/help-mode.el (help-xref-symbol-regexp, help-xref-info-regexp)
(help-xref-url-regexp):
* lisp/international/mule-cmds.el (help-xref-mule-regexp-template):
* lisp/wid-edit.el (widget-documentation-link-regexp):
Also match 'foo', in case we're in a help buffer generated when
help-quote-translation is ?'.
* src/doc.c: Include disptab.h, for DISP_CHAR_VECTOR.
(LEFT_SINGLE_QUOTATION_MARK, uLSQM0, uLSQM1, uLSQM2, uRSQM0)
(uRSQM1, uRSQM2, LSQM, RSQM): New constants.
(Fsubstitute_command_keys): Document and implement new behavior.
(Vhelp_quote_translation): Document new behavior.

4 files changed, 20 insertions, 19 deletions

diff --git a/lisp/emacs-lisp/cl-generic.el b/lisp/emacs-lisp/cl-generic.el
index 96b86aa21cc..5923e4db996 100644
--- a/lisp/emacs-lisp/cl-generic.el
+++ b/lisp/emacs-lisp/cl-generic.el
@@ -876,11 +876,11 @@ Can only be used from within the lexical body of a primary or around method."
                                    (cl--generic-method-specializers method)))
                    (file (find-lisp-object-file-name met-name 'cl-defmethod)))
               (when file
-                (insert " in ‘")
+                (insert (substitute-command-keys " in ‘"))
                 (help-insert-xref-button (help-fns-short-filename file)
                                          'help-function-def met-name file
                                          'cl-defmethod)
-                (insert "’.\n")))
+                (insert (substitute-command-keys "’.\n"))))
             (insert "\n" (or (nth 2 info) "Undocumented") "\n\n")))))))
 
 ;;; Support for (head <val>) specializers.
diff --git a/lisp/emacs-lisp/eieio-opt.el b/lisp/emacs-lisp/eieio-opt.el
index 11d99849a97..6cd6813956a 100644
--- a/lisp/emacs-lisp/eieio-opt.el
+++ b/lisp/emacs-lisp/eieio-opt.el
@@ -90,11 +90,11 @@ If CLASS is actually an object, then also display current values of that object.
 	  " class")
   (let ((location (find-lisp-object-file-name class 'eieio-defclass)))
     (when location
-      (insert " in ‘")
+      (insert (substitute-command-keys " in ‘"))
       (help-insert-xref-button
        (help-fns-short-filename location)
        'eieio-class-def class location 'eieio-defclass)
-      (insert "’")))
+      (insert (substitute-command-keys "’"))))
   (insert ".\n")
   ;; Parents
   (let ((pl (eieio-class-parents class))
@@ -103,10 +103,10 @@ If CLASS is actually an object, then also display current values of that object.
       (insert " Inherits from ")
       (while (setq cur (pop pl))
 	(setq cur (eieio--class-name cur))
-	(insert "‘")
+	(insert (substitute-command-keys "‘"))
 	(help-insert-xref-button (symbol-name cur)
 				 'help-function cur)
-	(insert (if pl "’, " "’")))
+	(insert (substitute-command-keys (if pl "’, " "’"))))
       (insert ".\n")))
   ;; Children
   (let ((ch (eieio-class-children class))
@@ -114,10 +114,10 @@ If CLASS is actually an object, then also display current values of that object.
     (when ch
       (insert " Children ")
       (while (setq cur (pop ch))
-	(insert "‘")
+	(insert (substitute-command-keys "‘"))
 	(help-insert-xref-button (symbol-name cur)
 				 'help-function cur)
-	(insert (if ch "’, " "’")))
+	(insert (substitute-command-keys (if ch "’, " "’"))))
       (insert ".\n")))
   ;; System documentation
   (let ((doc (documentation-property class 'variable-documentation)))
@@ -130,9 +130,9 @@ If CLASS is actually an object, then also display current values of that object.
     (when generics
       (insert (propertize "Specialized Methods:\n\n" 'face 'bold))
       (dolist (generic generics)
-        (insert "‘")
+        (insert (substitute-command-keys "‘"))
         (help-insert-xref-button (symbol-name generic) 'help-function generic)
-        (insert "’")
+        (insert (substitute-command-keys "’"))
 	(pcase-dolist (`(,qualifiers ,args ,doc)
                        (eieio-method-documentation generic class))
           (insert (format " %s%S\n" qualifiers args)
@@ -245,11 +245,11 @@ are not abstract."
 	(setq location
 	      (find-lisp-object-file-name ctr def)))
       (when location
-	(insert " in ‘")
+	(insert (substitute-command-keys " in ‘"))
 	(help-insert-xref-button
 	 (help-fns-short-filename location)
 	 'eieio-class-def ctr location 'eieio-defclass)
-	(insert "’"))
+	(insert (substitute-command-keys "’")))
       (insert ".\nCreates an object of class " (symbol-name ctr) ".")
       (goto-char (point-max))
       (if (autoloadp def)
diff --git a/lisp/emacs-lisp/lisp-mode.el b/lisp/emacs-lisp/lisp-mode.el
index ab01a109b7a..72a23cfdfc6 100644
--- a/lisp/emacs-lisp/lisp-mode.el
+++ b/lisp/emacs-lisp/lisp-mode.el
@@ -403,8 +403,8 @@
          ;; Words inside \\[] tend to be for `substitute-command-keys'.
          ("\\\\\\\\\\[\\(\\(?:\\sw\\|\\s_\\)+\\)\\]"
           (1 font-lock-constant-face prepend))
-         ;; Words inside ‘’ and `' tend to be symbol names.
-         ("[`‘]\\(\\(?:\\sw\\|\\s_\\)\\(?:\\sw\\|\\s_\\)+\\)['’]"
+         ;; Words inside ‘’ and '' and `' tend to be symbol names.
+         ("['`‘]\\(\\(?:\\sw\\|\\s_\\)\\(?:\\sw\\|\\s_\\)+\\)['’]"
           (1 font-lock-constant-face prepend))
          ;; Constant values.
          ("\\_<:\\(?:\\sw\\|\\s_\\)+\\_>" 0 font-lock-builtin-face)
@@ -452,8 +452,8 @@
          ;; Erroneous structures.
          (,(concat "(" cl-errs-re "\\_>")
            (1 font-lock-warning-face))
-         ;; Words inside ‘’ and `' tend to be symbol names.
-         ("[`‘]\\(\\(?:\\sw\\|\\s_\\)\\(?:\\sw\\|\\s_\\)+\\)['’]"
+         ;; Words inside ‘’ and '' and `' tend to be symbol names.
+         ("['`‘]\\(\\(?:\\sw\\|\\s_\\)\\(?:\\sw\\|\\s_\\)+\\)['’]"
           (1 font-lock-constant-face prepend))
          ;; Constant values.
          ("\\_<:\\(?:\\sw\\|\\s_\\)+\\_>" 0 font-lock-builtin-face)
diff --git a/lisp/emacs-lisp/package.el b/lisp/emacs-lisp/package.el
index 074d3e8dda3..62900e08360 100644
--- a/lisp/emacs-lisp/package.el
+++ b/lisp/emacs-lisp/package.el
@@ -2173,17 +2173,18 @@ will be deleted."
                                    "Installed"
                                  (capitalize status)) ;FIXME: Why comment-face?
                                'font-lock-face 'font-lock-comment-face))
-           (insert " in ‘")
+           (insert (substitute-command-keys " in ‘"))
            ;; Todo: Add button for uninstalling.
            (help-insert-xref-button (abbreviate-file-name
                                      (file-name-as-directory pkg-dir))
                                     'help-package-def pkg-dir)
            (if (and (package-built-in-p name)
                     (not (package-built-in-p name version)))
-               (insert "’,\n             shadowing a "
+               (insert (substitute-command-keys
+                        "’,\n             shadowing a ")
                        (propertize "built-in package"
                                    'font-lock-face 'font-lock-builtin-face))
-             (insert "’"))
+             (insert (substitute-command-keys "’")))
            (if signed
                (insert ".")
              (insert " (unsigned)."))