From c50dfa2be83b6df258c810cd1dc71ad947214803 Mon Sep 17 00:00:00 2001
From: Holger Vogt <holger.vogt@uni-due.de>
Date: Fri, 14 Jun 2019 22:22:17 +0200
Subject: [PATCH] prevent crash if function is called with NULL argument

---
 src/misc/string.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/misc/string.c b/src/misc/string.c
index 14d049514..19cecec10 100644
--- a/src/misc/string.c
+++ b/src/misc/string.c
@@ -319,6 +319,8 @@ gettok(char **s)
 char *
 nexttok(const char *s)
 {
+    if (!s)
+        return NULL;
     int paren = 0;
 
     s = skip_ws(s);