[Emacs-diffs] Changes to emacs/lisp/help-fns.el,v

[John Paul Wallington]

CVSROOT:        /sources/emacs
Module name:    emacs
Changes by:     John Paul Wallington <jpw>      07/10/20 01:50:38

Index: help-fns.el
===================================================================
RCS file: /sources/emacs/emacs/lisp/help-fns.el,v
retrieving revision 1.107
retrieving revision 1.108
diff -u -b -r1.107 -r1.108
--- help-fns.el 19 Oct 2007 01:12:54 -0000      1.107
+++ help-fns.el 20 Oct 2007 01:50:38 -0000      1.108
@@ -456,6 +456,28 @@
              (and (or any-symbol (boundp sym)) sym)))))
       0))
 
+(defun describe-variable-custom-version-info (variable)
+  (let ((custom-version (get variable 'custom-version))
+       (cpv (get variable 'custom-package-version))
+       (output nil))
+    (if custom-version
+       (setq output
+             (format "This variable was introduced, or its default value was 
changed, in\nversion %s of Emacs.\n"
+                     custom-version))
+      (when cpv
+       (let* ((package (car-safe cpv))
+              (version (car (cdr-safe cpv)))
+              (pkg-versions (assq package 
customize-package-emacs-version-alist))
+              (emacsv (cdr (assoc version pkg-versions))))
+         (if (and package version)
+             (setq output
+                   (format (concat "This variable was introduced, or its 
default value was changed, in\nversion %s of the %s package"
+                                   (if emacsv
+                                       (format " that is part of Emacs %s" 
emacsv))
+                                   ".\n")
+                           version package))))))
+    output))
+
 ;;;###autoload
 (defun describe-variable (variable &optional buffer frame)
   "Display the full documentation of VARIABLE (a symbol).
@@ -646,7 +668,7 @@
              (with-current-buffer standard-output
                (insert (or doc "Not documented as a variable."))))
            ;; Make a link to customize if this variable can be customized.
-           (if (custom-variable-p variable)
+           (when (custom-variable-p variable)
                (let ((customize-label "customize"))
                  (terpri)
                  (terpri)
@@ -655,7 +677,14 @@
                    (save-excursion
                      (re-search-backward
                       (concat "\\(" customize-label "\\)") nil t)
-                     (help-xref-button 1 'help-customize-variable variable)))))
+                   (help-xref-button 1 'help-customize-variable variable))))
+             ;; Note variable's version or package version
+             (let ((output (describe-variable-custom-version-info variable)))
+               (when output
+                 (terpri)
+                 (terpri)
+                 (princ output))))
+
            (print-help-return-message)
            (save-excursion
              (set-buffer standard-output)