ls-lisp: get rid of the dreaded "no effect until you restart Emacs".

* lisp/ls-lisp.el (ls-lisp-set-options): New function.
(ls-lisp-emulation): Use ls-lisp-set-options for custom :set.  Doc fix.

2 files changed, 26 insertions, 7 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index eae2a294bf8..5ba650c43b0 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -7,6 +7,9 @@
         (ls-lisp-verbosity, ls-lisp-use-localized-time-format): Doc fixes.
         (ls-lisp-format, ls-lisp-format-time): Don't take `now' as an argument.
         (ls-lisp-insert-directory): Update caller.
+        (ls-lisp-set-options): New function.
+        (ls-lisp-emulation): Use ls-lisp-set-options for custom :set.
+        Doc fix.
 
         * play/landmark.el (lm-prompt-for-move):
         * play/gomoku.el (gomoku-prompt-for-move): Remove nonsensical code.
diff --git a/lisp/ls-lisp.el b/lisp/ls-lisp.el
index 3791f6f5978..5f76c1bab7f 100644
--- a/lisp/ls-lisp.el
+++ b/lisp/ls-lisp.el
@@ -70,21 +70,37 @@
   :version "21.1"
   :group 'dired)
 
+(defun ls-lisp-set-options ()
+  "Reset the ls-lisp options that depend on `ls-lisp-emulation'."
+  (mapc 'custom-reevaluate-setting
+        '(ls-lisp-ignore-case ls-lisp-dirs-first ls-lisp-verbosity)))
+
 (defcustom ls-lisp-emulation
   (cond ;; ((eq system-type 'windows-nt) 'MS-Windows)
-        ((memq system-type
-               '(hpux usg-unix-v irix berkeley-unix))
-         'UNIX))                        ; very similar to GNU
+        ((memq system-type '(hpux usg-unix-v irix berkeley-unix))
+         'UNIX))        ; very similar to GNU
   ;; Anything else defaults to nil, meaning GNU.
   "Platform to emulate: GNU (default), MacOS, MS-Windows, UNIX.
-Corresponding value is one of the atoms: nil, MacOS, MS-Windows, UNIX.
-Sets default values for: `ls-lisp-ignore-case', `ls-lisp-dirs-first',
-`ls-lisp-verbosity'.  Need not match actual platform.  Changing this
-option will have no effect until you restart Emacs."
+Corresponding value is one of: nil, `MacOS', `MS-Windows', `UNIX'.
+Set this to your preferred value; it need not match the actual platform
+you are using.
+
+This variable does not affect the behavior of ls-lisp directly.
+Rather, it controls the default values for some variables that do:
+`ls-lisp-ignore-case', `ls-lisp-dirs-first', and `ls-lisp-verbosity'.
+
+If you change this variable directly (without using customize)
+after loading `ls-lisp', you should use `ls-lisp-set-options' to
+update the dependent variables."
   :type '(choice (const :tag "GNU" nil)
                  (const MacOS)
                  (const MS-Windows)
                  (const UNIX))
+  :initialize 'custom-initialize-default
+  :set (lambda (symbol value)
+         (unless (equal value (eval symbol))
+           (custom-set-default symbol value)
+           (ls-lisp-set-options)))
   :group 'ls-lisp)
 
 (defcustom ls-lisp-ignore-case