From 7d5fa586cfbe20cc1173d93f74c9c9a2a6821e3f Mon Sep 17 00:00:00 2001
From: erg <devnull@localhost>
Date: Wed, 30 Nov 2005 22:19:52 +0000
Subject: [PATCH] Prevent core dump when a cluster has no label to be used as a
 tooltip.

---
 lib/common/emit.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/common/emit.c b/lib/common/emit.c
index 65994c3d8..baa0b9c6e 100644
--- a/lib/common/emit.c
+++ b/lib/common/emit.c
@@ -1439,7 +1439,7 @@ void emit_clusters(GVJ_t * job, Agraph_t * g, int flags)
 	if ((s = agget(sg, "tooltip")) && s[0]) {
 	    tooltip = strdup_and_subst_graph(s, sg);
 	    explicit_tooltip++;
-	} else {
+	} else if (GD_label(sg)) {
 	    tooltip = strdup_and_subst_graph(GD_label(sg)->text, sg);
 	}
 	if (url || explicit_tooltip)
-- 
2.50.1