+(defun dgnushack-find-lisp-shadows (&optional lispdir)
+ "Return a list of directories in which other Gnus installations exist.
+This function looks for the other Gnus installations which will shadow
+the new Gnus Lisp modules which have been installed in LISPDIR, using
+the default `load-path'. The return value will make sense only when
+LISPDIR is existent and is listed in the default `load-path'. Assume
+LISPDIR will be prepended to `load-path' by a user if the default
+`load-path' does not contain it."
+ (unless lispdir
+ (setq lispdir (getenv "lispdir")))
+ (when (and lispdir (file-directory-p lispdir))
+ (setq lispdir (file-truename (directory-file-name lispdir)))
+ (let ((indices '("gnus.elc" "gnus.el" "gnus.el.bz2" "gnus.el.gz"
+ "message.elc" "message.el" "message.el.bz2"
+ "message.el.gz"))
+ (path (delq nil (mapcar
+ (lambda (p)
+ (condition-case nil
+ (when (and p (file-directory-p p))
+ (file-truename (directory-file-name p)))
+ (error nil)))
+ dgnushack-default-load-path)))
+ rest elcs)
+ (while path
+ (setq rest (cons (car path) rest)
+ path (delete (car rest) (cdr path))))
+ (setq path (nreverse (cdr (member lispdir rest)))
+ rest nil)
+ (while path
+ (setq elcs indices)
+ (while elcs
+ (when (file-exists-p (expand-file-name (pop elcs) (car path)))
+ (setq rest (cons (car path) rest)
+ elcs nil)))
+ (setq path (cdr path)))
+ (prog1
+ (setq path (nreverse rest))
+ (when path
+ (let (print-level print-length)
+ (princ (concat "\n\
+WARNING: The other Gnus installation" (if (cdr path) "s have" " has") "\
+ been detected in:\n\n " (mapconcat 'identity path "\n ") "\n\n\
+You will need to modify the run-time `load-path', remove them manually,
+or remove them using `make remove-installed-shadows'.\n\n"))))))))
+
+(defun dgnushack-remove-lisp-shadows (&optional lispdir)
+ "Remove the other Gnus installations which shadow the recent one."
+ (let ((path (with-temp-buffer
+ (let ((standard-output (current-buffer)))
+ (dgnushack-find-lisp-shadows lispdir))))
+ elcs files shadows file)
+ (when path
+ (unless (setq elcs (directory-files srcdir nil "\\.elc\\'"))
+ (error "You should build .elc files first."))
+ (setq files
+ (apply
+ 'append
+ (mapcar
+ (lambda (el)
+ (list (concat el "c") el (concat el ".bz2") (concat el ".gz")))
+ (append
+ (list (file-name-nondirectory dgnushack-gnus-load-file)
+ (file-name-nondirectory dgnushack-cus-load-file))
+ (mapcar (lambda (elc) (substring elc 0 -1)) elcs)))))
+ (while path
+ (setq shadows files)
+ (while shadows
+ (setq file (expand-file-name (pop shadows) (car path)))
+ (when (file-exists-p file)
+ (princ (concat " Removing " file "..."))
+ (condition-case nil
+ (progn
+ (delete-file file)
+ (princ "done\n"))
+ (error (princ "failed\n")))))
+ (setq path (cdr path))))))