From ba7ad783a829d93b7f9b713be645a17cc60d4c09 Mon Sep 17 00:00:00 2001
From: Holger Vogt <holger.vogt@uni-due.de>
Date: Wed, 17 May 2023 09:32:23 +0200
Subject: [PATCH] safeguard against crash upon buggy input

---
 src/frontend/inpcom.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/frontend/inpcom.c b/src/frontend/inpcom.c
index 1f4994c7b..dd83a62f4 100644
--- a/src/frontend/inpcom.c
+++ b/src/frontend/inpcom.c
@@ -4483,7 +4483,8 @@ static int inp_get_param_level(
     return level;
 }
 
-
+/* Return the number of terminals for a given device, characterized by
+   the first letter of its instance line. Returns 0 upon error. */
 int get_number_terminals(char *c)
 {
     int i, j, k;
@@ -4491,6 +4492,9 @@ int get_number_terminals(char *c)
     char nam_buf[128];
     bool area_found = FALSE;
 
+    if (!c)
+        return 0;
+
     switch (*c) {
         case 'r':
         case 'c':