+(defvar customize-changed-options-previous-release "20.2"
+ "Version for `customize-changed-options' to refer back to by default.")
+
+;;;###autoload
+(defun customize-changed-options (since-version)
+ "Customize all user option variables changed in Emacs itself.
+This includes new user option variables and faces, and new
+customization groups, as well as older options and faces whose default
+values have changed since the previous major Emacs release.
+
+With argument SINCE-VERSION (a string), customize all user option
+variables that were added (or their meanings were changed) since that
+version."
+
+ (interactive "sCustomize options changed, since version (default all versions): ")
+ (if (equal since-version "")
+ (setq since-version nil)
+ (unless (condition-case nil
+ (numberp (read since-version))
+ (error nil))
+ (signal 'wrong-type-argument (list 'numberp since-version))))
+ (unless since-version
+ (setq since-version customize-changed-options-previous-release))
+ (let ((found nil)
+ (versions nil))
+ (mapatoms (lambda (symbol)
+ (and (or (boundp symbol)
+ ;; For variables not yet loaded.
+ (get symbol 'standard-value)
+ ;; For groups the previous test fails, this one
+ ;; could be used to determine if symbol is a
+ ;; group. Is there a better way for this?
+ (get symbol 'group-documentation))
+ (let ((version (get symbol 'custom-version)))
+ (and version
+ (or (null since-version)
+ (customize-version-lessp since-version version))
+ (if (member version versions)
+ t
+ ;;; Collect all versions that we use.
+ (push version versions))))
+ (setq found
+ ;; We have to set the right thing here,
+ ;; depending if we have a group or a
+ ;; variable.
+ (if (get symbol 'group-documentation)
+ (cons (list symbol 'custom-group) found)
+ (cons (list symbol 'custom-variable) found))))))
+ (if (not found)
+ (error "No user option defaults have been changed since Emacs %s"
+ since-version)
+ (let ((flist nil))
+ (while versions
+ (push (copy-sequence
+ (cdr (assoc (car versions) custom-versions-load-alist)))
+ flist)
+ (setq versions (cdr versions)))
+ (put 'custom-versions-load-alist 'custom-loads
+ ;; Get all the files that correspond to element from the
+ ;; VERSIONS list. This could use some simplification.
+ (apply 'nconc flist)))
+ ;; Because we set all the files needed to be loaded as a
+ ;; `custom-loads' property to `custom-versions-load-alist' this
+ ;; call will actually load them.
+ (custom-load-symbol 'custom-versions-load-alist)
+ ;; Clean up
+ (put 'custom-versions-load-alist 'custom-loads nil)
+ (custom-buffer-create (custom-sort-items found t 'first)
+ "*Customize Changed Options*"))))
+
+(defun customize-version-lessp (version1 version2)
+ ;; Why are the versions strings, and given that they are, why aren't
+ ;; they converted to numbers and compared as such here? -- fx
+
+ ;; In case someone made a mistake and left out the quotes
+ ;; in the :version value.
+ (if (numberp version2)
+ (setq version2 (prin1-to-string version2)))
+ (let (major1 major2 minor1 minor2)
+ (string-match "\\([0-9]+\\)\\(\\.\\([0-9]+\\)\\)?" version1)
+ (setq major1 (read (or (match-string 1 version1)
+ "0")))
+ (setq minor1 (read (or (match-string 3 version1)
+ "0")))
+ (string-match "\\([0-9]+\\)\\(\\.\\([0-9]+\\)\\)?" version2)
+ (setq major2 (read (or (match-string 1 version2)
+ "0")))
+ (setq minor2 (read (or (match-string 3 version2)
+ "0")))
+ (or (< major1 major2)
+ (and (= major1 major2)
+ (< minor1 minor2)))))
+