(message-cite-original): If mail-citation-hook

is non-nil, just run that and do nothing else.
(message-cite-function): Don't initialize from mail-citation-hook.

lisp/gnus/message.el

@@ -463,11 +463,11 @@ Used by `message-yank-original' via `message-yank-cite'."
 
 ;;;###autoload
 (defcustom message-cite-function
-  (if (and (boundp 'mail-citation-hook)
-	   mail-citation-hook)
-      mail-citation-hook
-    'message-cite-original)
-  "*Function for citing an original message."
+  'message-cite-original
+  "*Function for citing an original message.
+Predefined functions include `message-cite-original' and
+`message-cite-original-without-signature'.
+Note that `message-cite-original' uses `mail-citation-hook'if that is non-nil."
   :type '(radio (function-item message-cite-original)
 		(function-item sc-cite-original)
 		(function :tag "Other"))
@@ -1629,19 +1629,22 @@ prefix, and don't delete any headers."
 
 (defun message-cite-original ()
   "Cite function in the standard Message manner."
-  (let ((start (point))
-	(functions
-	 (when message-indent-citation-function
-	   (if (listp message-indent-citation-function)
-	       message-indent-citation-function
-	     (list message-indent-citation-function)))))
-    (goto-char start)
-    (while functions
-      (funcall (pop functions)))
-    (when message-citation-line-function
-      (unless (bolp)
-	(insert "\n"))
-      (funcall message-citation-line-function))))
+  (if (and (boundp 'mail-citation-hook)
+	   mail-citation-hook)
+      (run-hooks 'mail-citation-hook)
+    (let ((start (point))
+	  (functions
+	   (when message-indent-citation-function
+	     (if (listp message-indent-citation-function)
+		 message-indent-citation-function
+	       (list message-indent-citation-function)))))
+      (goto-char start)
+      (while functions
+	(funcall (pop functions)))
+      (when message-citation-line-function
+	(unless (bolp)
+	  (insert "\n"))
+	(funcall message-citation-line-function)))))
 
 (defun message-insert-citation-line ()
   "Function that inserts a simple citation line."