From c9026cec2d1063331b908aa9cb03b414e9f9742a Mon Sep 17 00:00:00 2001
From: Gerd Moellmann <gerd@gnu.org>
Date: Mon, 18 Dec 2000 17:10:50 +0000
Subject: [PATCH] (tooltip-mode): Signal an error if x-show-tip isn't fboundp.

---
 lisp/tooltip.el | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/lisp/tooltip.el b/lisp/tooltip.el
index dada23d0c2e..e02eec71884 100644
--- a/lisp/tooltip.el
+++ b/lisp/tooltip.el
@@ -197,6 +197,8 @@ This might return nil if the event did not occur over a buffer."
   "Mode for tooltip display.
 With ARG, turn tooltip mode on if and only if ARG is positive."
   (interactive "P")
+  (unless (fboundp 'x-show-tip)
+    (error "Sorry, tooltips are not yet available on this system"))
   (let* ((on (if arg
 		 (> (prefix-numeric-value arg) 0)
 	       (not tooltip-mode)))
-- 
2.30.2