From ec6d6769202814c3035d67ec35c3bd6df7effe5c Mon Sep 17 00:00:00 2001
From: Holger Vogt <holger.vogt@uni-due.de>
Date: Sun, 8 Sep 2019 09:35:55 +0200
Subject: [PATCH] Make CopyGraph safe against NULL argument. Otherwise memcpy
 will fail.

---
 src/frontend/plotting/graphdb.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/frontend/plotting/graphdb.c b/src/frontend/plotting/graphdb.c
index c4a2d70fb..09ba1dc90 100644
--- a/src/frontend/plotting/graphdb.c
+++ b/src/frontend/plotting/graphdb.c
@@ -109,6 +109,9 @@ CopyGraph(GRAPH *graph)
     struct _keyed *k;
     struct dveclist *link, *newlink;
 
+    if (!graph)
+        return NULL;
+
     ret = NewGraph();
     memcpy(ret, graph, sizeof(GRAPH)); /* va: compatible pointer types */