This is a patch for a preference-corruption issue.  XEmacs corrupts the ~/.emacs file when you follow the steps below.  It has happened to me both on Ubuntu Linux and on FreeBSD.  The poor guy posting at https://stat.ethz.ch/pipermail/ess-help/2005-September/002851.html also experienced it.

Fix: See attached patch.  To make the patch, I copied two lines from 
http://cvs.savannah.gnu.org/viewvc/emacs/emacs/lisp/cus-edit.el?revision=1.321&view=markup into the xemacs21-devel-mule port's unpacked source.  Then I modified it to check even more aggressively: it refuses to try to save a user's customizations any time the init file didn't fully load, even if the custom file is a different file than the init file.  This is because it seems that the variable custom-file was set (to /home/j/.emacs) on my PC and I am worried it may be set elsewhere too.

I tested the patch by deleting my cus-edit.elc and pasting in the new cus-edit.el in my xemacs lisp directory.  It works fine.

Here is the patch:



Dear FreeBSD people, could you please forward the patch onto the XEmacs people?  Please let me know.

Regards,
Jason--2a4JsTCCeCb18JknbOnMc8jFMUjCCb6x41jss9DmFP9w4jj2
Content-Type: text/plain; name="file.diff"
Content-Transfer-Encoding: 7bit
Content-Disposition: attachment; filename="file.diff"

--- xemacs-21.5.27/lisp/cus-edit.el.orig        Tue Jun 26 04:10:18 2007
+++ xemacs-21.5.27/lisp/cus-edit.el     Tue Jun 26 04:14:52 2007
@@ -3756,6 +3756,8 @@
 ;;;###autoload
 (defun custom-save-all ()
   "Save all customizations in `custom-file'."
+  (when init-file-had-error
+    (error "Cannot save customizations; init file was not fully loaded"))
   (let ((inhibit-read-only t))
     (custom-save-variables)
     (custom-save-faces)
How-To-Repeat: * Add something to the top of the file (somewhere above the custom-set-variables statement) that xemacs can't understand, such as the lone word:
    foobarbazquux
* Start xemacs for the first time
* At the "Migrate init file to ~/.xemacs/? (yes or no)" prompt, enter "no"

Now XEmacs will clobber the custom-set-variables and custom-set-fonts clauses in your ~/.emacs file.  It replaces them with:

(custom-set-variables
 '(load-home-init-file t t))
(custom-set-faces)