(desktop-save): Save list of minor modes.

(desktop-create-buffer): Restore minor modes.
(desktop-minor-mode-table): New user-option.

diff --git a/lisp/desktop.el b/lisp/desktop.el
index 5fafd4df55747771c808d388bfa90ae2cd1a4850..e59d57c07fc626e5312a80504ed132a10ae2c81b 100644 (file)
--- a/lisp/desktop.el
+++ b/lisp/desktop.el
@@ -41,11 +41,10 @@
 ;;     (desktop-load-default)
 ;;     (desktop-read)
 ;;
-;; Between the second and the third line you may wish to add something that
-;; updates the variables `desktop-globals-to-save' and/or
-;; `desktop-locals-to-save'.  If for instance you want to save the local
-;; variable `foobar' for every buffer in which it is local, you could add
-;; the line
+;; Between these two lines you may wish to add something that updates the
+;; variables `desktop-globals-to-save' and/or `desktop-locals-to-save'.  If
+;; for instance you want to save the local variable `foobar' for every buffer
+;; in which it is local, you could add the line
 ;;
 ;;     (setq desktop-locals-to-save (cons 'foobar desktop-locals-to-save))
 ;;
@@ -58,8 +57,8 @@
 ;;                  (desktop-truncate regexp-search-ring 3)))
 ;;
 ;; which will make sure that no more than three search items are saved.  You
-;; must place this line *after* the (load "desktop") line.  See also the
-;; variable desktop-save-hook.
+;; must place this line *after* the `(desktop-load-default)' line.  See also
+;; the variable `desktop-save-hook'.
 
 ;; Start Emacs in the root directory of your "project". The desktop saver
 ;; is inactive by default.  You activate it by M-x desktop-save RET.  When
@@ -70,6 +69,14 @@
 ;; act as a default desktop when you start Emacs from a directory that
 ;; doesn't have its own.  I never do this, but you may want to.
 
+;; Some words on minor modes: Most minor modes are controlled by
+;; buffer-local variables, which have a standard save / restore
+;; mechanism.  To handle all minor modes, we take the following
+;; approach: (1) check whether the variable name from
+;; `minor-mode-alist' is also a function; and (2) use translation
+;; table `desktop-minor-mode-table' in the case where the two names
+;; are not the same.
+
 ;; By the way: don't use desktop.el to customize Emacs -- the file .emacs
 ;; in your home directory is used for that.  Saving global default values
 ;; for buffers is an example of misuse.
@@ -218,6 +225,20 @@ This is useful for truncating history lists, for example."
   :type 'hook
   :group 'desktop)
 
+(defcustom desktop-minor-mode-table
+  '((auto-fill-function auto-fill-mode)
+    (vc-mode nil))
+  "Table mapping minor mode variables to minor mode functions.
+Each entry has the form (NAME RESTORE-FUNCTION).
+NAME is the name of the buffer-local variable indicating that the minor
+mode is active.  RESTORE-FUNCTION is the function to activate the minor mode.
+called.  RESTORE-FUNCTION nil means don't try to restore the minor mode.
+Only minor modes for which the name of the buffer-local variable
+and the name of the minor mode function are different have to added to
+this table."
+  :type 'sexp
+  :group 'desktop)
+
 ;; ----------------------------------------------------------------------------
 (defvar desktop-dirname nil
   "The directory in which the current desktop file resides.")
@@ -394,7 +415,7 @@ which means to truncate VAR's value to at most MAX-SIZE elements
          (if (and (integerp size)
                   (> size 0)
                   (listp (eval var)))
-             (desktop-truncate (eval var) size)) 
+             (desktop-truncate (eval var) size))
          (insert "(setq "
                  (symbol-name var)
                  " "
@@ -426,14 +447,26 @@ MODE is the major mode."
                     (concat dirname desktop-basefilename)))
          (info (nreverse
                 (mapcar
-                 (function (lambda (b)
+                 (function
+                  (lambda (b)
                              (set-buffer b)
                              (list
                               (buffer-file-name)
                               (buffer-name)
                               major-mode
-                              (list    ; list explaining minor modes
-                               (not (null auto-fill-function)))
+                              ;; minor modes
+                              (let (ret)
+                                (mapcar
+                                 #'(lambda (mim)
+                                     (and (symbol-value mim)
+                                          (setq ret
+                                                (cons (let ((special (assq mim desktop-minor-mode-table)))
+                                                       (if special
+                                                           (cadr special)
+                                                         mim))
+                                                     ret))))
+                                 (mapcar #'car minor-mode-alist))
+                                ret)
                               (point)
                               (list (mark t) mark-active)
                               buffer-read-only
@@ -589,7 +622,8 @@ to provide correct modes for autoloaded files."
 ;; only.
 (defun desktop-create-buffer (ver desktop-buffer-file-name desktop-buffer-name
                                  desktop-buffer-major-mode
-                                 mim pt mk ro desktop-buffer-misc &optional locals)
+                                 mim pt mk ro desktop-buffer-misc
+                                 &optional locals)
   (let ((hlist desktop-buffer-handlers)
        (result)
        (handler))
@@ -601,7 +635,12 @@ to provide correct modes for autoloaded files."
       (set-buffer result)
       (if (not (equal (buffer-name) desktop-buffer-name))
          (rename-buffer desktop-buffer-name))
-      (auto-fill-mode (if (nth 0 mim) 1 0))
+      ;; minor modes
+      (cond ((equal '(t) mim)   (auto-fill-mode 1))    ; backwards compatible
+           ((equal '(nil) mim) (auto-fill-mode 0))
+           (t (mapcar #'(lambda (minor-mode)
+                          (when minor-mode (funcall minor-mode 1)))
+                          mim)))
       (goto-char pt)
       (if (consp mk)
          (progn