Allow using `customize-save-variable' under Emacs -Q: Set the variable, and give a warning

2 files changed, 31 insertions, 17 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index e024646cd26..f1c36a9feea 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,9 @@
+2011-07-11  Lars Magne Ingebrigtsen  <larsi@gnus.org>
+
+        * cus-edit.el (custom-file): Take an optional no-error variable.
+        (customize-save-variable): Set the variable, and give a warning if
+        running under "emacs -q".
+
 2011-07-11  Juanma Barranquero  <lekktu@gmail.com>
 
         * loadhist.el (unload-feature-special-hooks):
diff --git a/lisp/cus-edit.el b/lisp/cus-edit.el
index 22b7cc6b3fe..d443d6c160c 100644
--- a/lisp/cus-edit.el
+++ b/lisp/cus-edit.el
@@ -1033,7 +1033,11 @@ If given a prefix (or a COMMENT argument), also prompt for a comment."
          (put variable 'saved-variable-comment comment)))
   (put variable 'customized-value nil)
   (put variable 'customized-variable-comment nil)
-  (custom-save-all)
+  (if (custom-file t)
+      (custom-save-all)
+    (message "Setting `%s' temporarily since \"emacs -q\" would overwrite customizations"
+             variable)
+    (set variable value))
   value)
 
 ;; Some parts of Emacs might prompt the user to save customizations,
@@ -4403,23 +4407,27 @@ Click on \"More\" \(or position point there and press RETURN)
 if only the first line of the docstring is shown."))
   :group 'customize)
 
-(defun custom-file ()
+(defun custom-file (&optional no-error)
   "Return the file name for saving customizations."
-  (file-chase-links
-   (or custom-file
-       (let ((user-init-file user-init-file)
-             (default-init-file
-               (if (eq system-type 'ms-dos) "~/_emacs" "~/.emacs")))
-         (when (null user-init-file)
-           (if (or (file-exists-p default-init-file)
-                   (and (eq system-type 'windows-nt)
-                        (file-exists-p "~/_emacs")))
-               ;; Started with -q, i.e. the file containing
-               ;; Custom settings hasn't been read.  Saving
-               ;; settings there would overwrite other settings.
-               (error "Saving settings from \"emacs -q\" would overwrite existing customizations"))
-           (setq user-init-file default-init-file))
-         user-init-file))))
+  (let ((file
+         (or custom-file
+             (let ((user-init-file user-init-file)
+                   (default-init-file
+                     (if (eq system-type 'ms-dos) "~/_emacs" "~/.emacs")))
+               (when (null user-init-file)
+                 (if (or (file-exists-p default-init-file)
+                         (and (eq system-type 'windows-nt)
+                              (file-exists-p "~/_emacs")))
+                     ;; Started with -q, i.e. the file containing
+                     ;; Custom settings hasn't been read.  Saving
+                     ;; settings there would overwrite other settings.
+                     (if no-error
+                         nil
+                       (error "Saving settings from \"emacs -q\" would overwrite existing customizations"))
+                   (setq user-init-file default-init-file)))
+               user-init-file))))
+    (and file
+         (file-chase-links file))))
 
 ;; If recentf-mode is non-nil, this is defined.
 (declare-function recentf-expand-file-name "recentf" (name))